Highlights
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2026, 55(11):2980-2992. DOI: 10.12442/j.issn.1002-185X.20250468Abstract:
Titanium and titanium alloys, owing to their low density, high specific strength, and excellent corrosion resistance, are widely used in aerospace and marine engineering. The development of additive manufacturing has enabled new approaches for fabricating complex titanium and titanium alloy components. As a solid-state additive manufacturing technique, cold spray has attracted considerable attention for its advantages of low deposition temperature, high spraying velocity, and minimal thermal effects. The current research status of cold spray additive manufacturing of titanium and titanium alloy coating was reviewed. The characteristics of feedstock powders and their influence on deposition behavior were introduced. The microstructure and properties of cold-sprayed deposits were analyzed, and the mechanisms and effects of strengthening strategies such as in-situ reinforcement and post-processing were summarized, providing a reference for process improvement and application expansion.2026, 55(11):2937-2947. DOI: 10.12442/j.issn.1002-185X.20250417Abstract:
Porous metallic materials are a class of materials characterized by their structurally and functionally integrated features, with a well-defined pore structure being their most notable attribute. This porous structure enables them to exhibit dual characteristics of both metallic and porous materials, making them widely applicable in fields such as nuclear industry, petrochemical engineering, and aerospace. Additive manufacturing technology allows for the integrated fabrication of complex porous metallic structures, offering advantages such as high material utilization rate and precise control over pore structure. This paper reviews the current development of additive manufacturing technologies for metallic porous materials, focusing on the pore formation mechanisms and performance characteristics of additively manufactured porous metallic materials. It also summarizes their application progress in industries such as healthcare and mold manufacturing, discusses the integration of artificial intelligence in metallic additive manufacturing, and provides an outlook on the future development of this technology.2026, 55(11):2916-2927. DOI: 10.12442/j.issn.1002-185X.20250497Abstract:
The dealloying strategy based on dilute solid solution precursor holds significant importance in nanoporous metal fabrication. While conventional dealloying is constrained by the narrow compositional range of binary alloys, the dilute solid solution precursors achieve precise control over porous architectures by substantially expanding the tunable compositional range and optimizing kinetic pathways. Results show that structures such as high-aspect-ratio nanoporous microwires, ultra-high porosity freestanding thin films, and nested hierarchical nanoporous metals are fabricated, demonstrating significant advantages in functional applications: electrocatalytic materials achieve enhanced hydrogen evolution performance by optimizing surface electronic structures; solar steam generation devices leverage hierarchical porosity and localized surface plasmon resonance effects to attain broadband light absorption and efficient evaporation; and electroactuator materials overcome the limits of strain amplitude and strain rate by hierarchical network design. Critically, this strategy reveals a novel mechanism for synergistically resolving the fundamental compromise between high specific surface area/mass transfer efficiency and mechanical stability through the coordinated design of precursor composition and dealloying parameters.2026, 55(11):2894-2915. DOI: 10.12442/j.issn.1002-185X.20250646Abstract:
Laser powder bed fusion (LPBF) has emerged as a powerful additive manufacturing technique for fabricating architected cellular metallic structures with precisely tailored properties, making it particularly attractive for biomedical applications such as bone implants, scaffolds, and load-bearing devices. By enabling lightmass designs, complex geometries, and tunable mechanical behavior, LPBF offers unique opportunities for matching implant performance with biological and mechanical requirements. However, the intricate coupling between LPBF process parameters and the resulting structural, microstructural, and mechanical properties remain a major challenge for achieving the consistency and reliability demanded in clinical practice. This review comprehensively analyzed the effects of key LPBF parameters, such as laser power, scanning speed, and layer thickness on dimensional accuracy, relative density, microstructure, and surface roughness of metallic cellular structures. Their subsequent influence on mechanical performance, such as strength, fatigue resistance, and functional behavior, was critically discussed with a focus on biomedical relevance. In addition, the role of lattice design variables, including topology, unit cell size, and build orientation, was examined, highlighting their importance in optimizing mechanical integrity and biocompatibility. Current challenges, such as surface defects, geometric deviations, and microstructural heterogeneity, were identified as critical barriers to broader biomedical adoption. Finally, future perspectives emphasize process optimization and the integration of advanced computational approaches, particularly machine learning, to accelerate the design and manufacturing of complex, patient-specific biomedical architectures.2026, 55(11):2802-2811. DOI: 10.12442/j.issn.1002-185X.20250336Abstract:
Three types of truss rod unit lattice structures were nested within the honeycomb cavities to obtain a new honeycomb-nested lattice structure. Using AlSi10Mg powder as the material, samples with different relative densities of the new bcc honeycomb-nested lattice structure (HC-N-bcc), honeycomb-nested symmetric rod lattice structure (HC-SP), new fluorite-type honeycomb-nested lattice structure (HC-N-F), and hollow honeycomb structure (HC-E) were fabricated by the selective laser melting (SLM) technique. Lateral compression mechanical properties, macro-micro deformation mechanisms, and energy absorption analyses were conducted on these samples. The results show that the lateral compression performance of the honeycomb-nested lattice structures is significantly superior to that of the hollow honeycomb structure. At the relative density of 46%, the HC-SP structure exhibits a compression modulus and peak stress that are 43% and 44.7% higher than those of HC-E, respectively. Under the strain of 50%, its energy absorption () and crushing force efficiency (CFE) are 7.7 and 5.3 times higher than those of HC-E, respectively. When truss unit lattices are embedded in the honeycomb cavities, the honeycomb shell deforms gradually and uniformly instead of fracturing instantly, significantly improving the compressive stability of the honeycomb structure. Furthermore, the larger the proportion of the truss volume in the overall structure, the better the performance improvement of the honeycomb-nested lattice structure. -
2026, 55(10):2687-2712. DOI: 10.12442/j.issn.1002-185X.20250386Abstract:
Laser additive manufacturing, as an advanced digital forming technology, is widely used in the research of superalloy preparation. GH3536, as a solid solution strengthened nickel-based superalloy, is suitable for the preparation of components for combustion chambers of aero-engines due to its excellent mechanical properties. The control of metallurgical defects, microstructure modulation and mechanical property strengthening mechanism of laser additive manufacturing of GH3536 alloy were reviewed. The current research status and progress of laser additive manufacturing for GH3536 alloy were analyzed, and the research on the influence mechanism of its tensile and creep properties and other research was expected. It is hoped to provide reference for the research and development of laser additive manufacturing for GH3536 alloy.2026, 55(10):2665-2686. DOI: 10.12442/j.issn.1002-185X.20250302Abstract:
Nickel-based superalloys are widely used in critical hot-section components of high-end equipment such as aero-engines and gas turbines due to their excellent mechanical properties and oxidation resistance at elevated temperatures. As an advanced manufacturing method, laser directed energy deposition (L-DED) has demonstrated great potential in the repair of complex components, owing to its advantages such as mold-free near-net shaping, controllable energy input, small heat-affected zone, and dense microstructure in the deposited layer. However, during L-DED repair process, nickel-based superalloys undergo complex rapid melting and solidification, as well as repeated thermal cycling, resulting in unique microstructural features and a high tendency to develop typical metallurgical defects, such as pores, cracks, stray grains, and microstructure degradation, which can significantly degrade their mechanical performance. The typical defects and their control methods, as well as microstructural evolution characteristics were reviewed, and the key mechanical properties, including room-temperature tensile strength, high-temperature creep resistance, and fatigue performance, between directly deposited and repaired nickel-based superalloys were compared. Furthermore, based on existing theoretical models, the mechanisms of defect formation and microstructural evolution were analyzed, highlighting the current technical challenges and limitations in this field. This review provides a theoretical foundation and direction for the process optimization, microstructural control, and performance enhancement of L-DED-repaired or L-DED-formed nickel-based superalloys.2026, 55(10):2652-2664. DOI: 10.12442/j.issn.1002-185X.20250348Abstract:
Laser cladding is widely employed for surface strengthening of titanium alloys and other metals owing to its advantageous metallurgical bonding and narrow heat-affected zones. Among various strengthening materials, WC is used as a superhard ceramic phase. Through its synergistic effect with Co, the hardness and wear resistance of the cladding layer can be effectively enhanced. However, research has demonstrated that laser power exerts a significant influence on cladding layer quality. When excessive power is applied, excessive dissolution of WC particles occurs, facilitating crack initiation and pore formation. Conversely, insufficient power commonly leads to defects, such as unmelted particles and porosity. This review focused on the influence of laser power on WC grain size and growth mechanisms within the coating, and summarized the wear resistance mechanisms of the coating. Furthermore, the main limitations currently encountered in the preparation of WC-Co coatings were analyzed, along with corresponding improvement strategies. Finally, existing challenges and future development trends were discussed.2026, 55(10):2639-2651. DOI: 10.12442/j.issn.1002-185X.20250297Abstract:
Discontinuous yielding of metal materials during room-temperature deformation is a critical scientific issue that significantly affects their mechanical properties and application safety. This review summarized recent research advancements in this field, with a focus on the characteristics, influencing factors, and underlying mechanisms of discontinuous yielding. The discontinuous yielding phenomenon was mainly characterized by a yield drop and a stress plateau on the stress-strain curve. Results show that microstructural characteristics such as alloy composition, degree of recrystallization, grain size and morphology, as well as phase composition and stability, serve as primary factors influencing discontinuous yielding. These factors affect the yielding behavior by regulating dislocation movement and deformation mechanisms. Furthermore, the intrinsic relationship among discontinuous yielding, room-temperature deformation mechanism, and the work hardening behavior in metallic materials was explored. Based on current research, future studies should focus on the microstructure regulation, alloy design, deformation mechanisms, and the development of constitutive models to deepen the understanding of discontinuous yielding and to provide a foundation for optimizing material properties. -
2026, 55(9):2411-2420. DOI: 10.12442/j.issn.1002-185X.20250384Abstract:
Hydraulic machinery serves as the core equipment in hydropower stations and pumping stations, primarily encompassing turbines and pumps. Cavitation and erosion occurring on turbines stand out as the main causes of failure in flow-passing components, which have remained a critical challenge hindering the development of hydraulic machinery for over six decades. Numerous researchers have consistently found that applying a dense coating on the surface of the substrate material can effectively mitigate the damage to hydraulic machinery caused by cavitation and erosion. As an advanced surface modification technique, laser cladding has opened up new avenues for the industrial application of such coatings. By summarizing existing studies, this review comprehensively analyzed the mechanisms, influencing factors, and prediction methods of cavitation and erosion. It specifically summarized the impact of powder composition and operating conditions on the anti-cavitation and anti-erosion performances of laser cladding alloy coatings. Based on the above analysis, the review addressed the current drawbacks of materials in terms of anti-cavitation and anti-erosion performances, summarized the existing problems to date, and outlined the future development directions and trends of laser cladding alloy coatings. This work aimed to provide valuable references for the development of high-performance laser cladding coatings.2026, 55(9):2397-2410. DOI: 10.12442/j.issn.1002-185X.20250444Abstract:
High-entropy alloys (HEAs) are emerging alloy materials in recent years, breaking the inherent concept of designing traditional alloy compositions based on 1?2 major elements. Due to their unique structural features and performance advantages conferred by their multi-principal-element combinations, HEAs exhibit wide application prospects in marine engineering. In this review, the basic concepts and development status of HEAs have been introduced. Furthermore, their technological breakthrough, performance features, and corresponding mechanism analysis in different scenarios, including structural mechanics, coating protection, corrosion resistance, radiation tolerance, and component fabrication, have been reviewed. Special attention has been paid to the development status and application scenarios of HEAs in the field of shipbuilding and marine engineering. Some prominent problems currently existing in the research process of HEAs have been summarized, aiming to propose design methods and preparation directions of HEAs. More importantly, it also clarified novel development strategies to solve practical problems such as a series of corrosion and protection issues faced by HEAs under complex service conditions including marine engineering, along with new ideas for the future development of advanced HEAs that possess superior comprehensive performance and enhanced environmental adaptability.2026, 55(9):2238-2256. DOI: 10.12442/j.issn.1002-185X.20260028Abstract:
Over the past years, high-entropy metallic glasses (HEMGs) have attracted increasing research interest due to their unique structural characteristics arising from high configurational entropy, as well as distinctive properties such as sluggish diffusion, microstructural heterogeneity, enhanced glass-forming ability (GFA), and improved thermal/mechanical stability. Similar to conventional metallic glasses (MGs), HEMGs lack long-range atomic periodicity; however, the high-entropy effect introduces additional complexity in structural evolution, such as decoupling of the glass transition, potential glass-to-glass transitions, and a continuous polyamorphic transition during reheating. This enables HEMGs with tunable atomic rearrangement, atomic interactions, and chemical/topological heterogeneity, thereby conferring great potential for achieving superior structural and functional properties. Although several review papers have summarized the development of HEMGs, the rapid advancement of this field inspires us to provide a concise overview discussion of the latest research progress in HEMG-forming alloy systems. This review first focused on the GFA of newly developed HEMGs, followed by a comparative analysis of their unusual structural relaxation, crystallization behavior, and mechanical properties relative to conventional MGs. Finally, the unique atomic-scale structure and structural heterogeneity of HEMGs were reviewed, and the review concluded with a summary and outlook.2026, 55(9):2219-2237. DOI: 10.12442/j.issn.1002-185X.20250367Abstract:
Metallic glasses are a unique class of materials with exceptional mechanical properties, including high strength, excellent corrosion resistance, and significant elasticity. These materials display intriguing dynamical relaxation processes, which influence their mechanical and thermal properties. Understanding the dynamical relaxations in metallic glasses is crucial for optimizing their performance in various applications. Due to the restrictions of experimental techniques to access processes at the atomic level, the detailed mechanisms responsible for the dynamical relaxations cannot be easily obtained. Numerical simulations are potential candidates to analyze the elementary dynamical processes at the atomic scale and thus to capture the fundamental origin of dynamical relaxations. The development of computing has allowed researchers to reach an enormous advancement in the understanding of the physical mechanisms behind dynamical relaxations in metallic glasses. This review provided a brief overview of the current state of research in numerical simulations of dynamical relaxations in metallic glasses, highlighting key methodologies, significant findings, ongoing challenges, and future directions. By synthesizing current research, this review emphasizes the importance of these simulations in improving the design and processing of metallic glasses (from structural materials to high-performance components) for a wide range of applications.2026, 55(9):2209-2218. DOI: 10.12442/j.issn.1002-185X.20250552Abstract:
Metallic glasses exhibit exceptional properties but suffer from brittle fracture via shear banding at room temperature. Homogeneous deformation is vital for understanding amorphous plasticity. This review summarized recent advances in homogeneous deformation of metallic glasses in atomic-scale flow mechanisms, evolution of shear transformation zones, flow defects, and hierarchical relaxation processes. The correlation among free volume kinetics, stress-temperature equivalence, and rejuvenation threshold stress was introduced. Role of structural heterogeneity in flow stability was discussed, alongside the application of modern characterization and modeling techniques. The review proposed investigation methods for designing high ductile metallic glasses based on these insights.2026, 55(9):2179-2187. DOI: 10.12442/j.issn.1002-185X.20250585Abstract:
The universal generalizing approach for non-isothermal behaviour of different alloys was provided with the novel deformation modelling. Results show that strong correlation can be found between the predicted model and experiment results, which shows accurate estimation of main applied parameters, such as the linear thermal expansion coefficient. Necking contours and critical thickness at corrugation for ribbon and rod specimens can also be calculated. Fractal analysis of corrugation folds (their main size) was conducted for polycrystalline and amorphous ribbon specimens. Structural peculiarities at the plastic deformation stage were investigated. -
2026, 55(8):2099-2116. DOI: 10.12442/j.issn.1002-185X.20250155Abstract:
With the rapid development of human society, the discharge of various types of sewage has increased year by year, and environmental problems such as water pollution have become increasingly serious. Seeking effective sewage treatment methods has become an urgent need. Due to its excellent surface activity, low oxidation-reduction potential, and outstanding catalytic degradation performance, amorphous alloys are regarded as effective catalysts for solving various types of wastewater, such as dyeing wastewater. Currently, extensive research has been conducted on the treatment of wastewater containing organic pollutants such as dyes and pesticides, as well as inorganic pollutants such as heavy metals and acid-base salts. However, the degradation mechanism of amorphous alloys varies greatly depending on the type of wastewater and the amorphous alloy system, resulting in different degradation rates. Therefore, selecting suitable amorphous alloy components and appropriate material modification methods is crucial for achieving efficient degradation of wastewater. This review summarized the conventional techniques for wastewater treatment, the characteristics and potential of amorphous alloys, their applications in wastewater treatment, and the existing problems. It also reviewed the influence of various chemical parameters and other factors on the catalytic performance of amorphous alloys, as well as various material modification methods, aiming to provide valuable references for the research of new catalysts.2026, 55(8):2084-2098. DOI: 10.12442/j.issn.1002-185X.20250557Abstract:
TiAl alloy has important application value in aerospace and other high-temperature structural components due to its low density, high specific strength, and excellent creep resistance at high temperature. However, the high-temperature oxidation resistance of TiAl alloy in the environment above 750 ℃ is poor and the service life of some high-temperature service components under the condition of hot corrosion and high-temperature wear is reduced, which restrict its application. Double glow plasma alloying surface technology is an important way to enhance the surface protection ability without changing the overall performance of the substrate. The basic mechanism of the double glow plasma surface alloying technology was reviewed. The unit infiltration, dual infiltration, multi-component co-infiltration, and the composition and structure of infiltration coatings on high temperature oxidation resistance, hot corrosion resistance, and wear resistance were discussed. Finally, it outlined the future developing trends in the view of theoretical research, preparation process, and engineering applications.2026, 55(8):2074-2083. DOI: 10.12442/j.issn.1002-185X.20250239Abstract:
As a representative γ'-strengthened nickel-based superalloy, GH4099 is widely used in hot-end components under extreme service environments such as aviation, aerospace, and nuclear due to its excellent high-temperature performance, thermal stability, corrosion resistance, as well as fatigue resistance and fracture toughness. Laser powder bed fusion (LPBF) technique has effectively solved the technical bottlenecks such as prolonged processing cycle, insufficient process synergy, low material utilization, and high cost in the forming process of complex components by the traditional manufacturing technique. This review presents a comprehensive overview of the recent advancements in LPBF technique for the formation of GH4099 and delved into various aspects of GH4099 superalloys prepared by LPBF, including its technical principles, solidification defects, microstructure, and high-temperature mechanical properties. Furthermore, it focused on the influence of powder characteristics, process parameters, post-treatment techniques (including heat treatment and hot isostatic pressing technique), and other factors on the solidification defects and high-temperature mechanical properties of GH4099 superalloys prepared by LPBF. Finally, it summarized and outlined the application potential and development trends of this technique in future manufacturing.2026, 55(8):1958-1966. DOI: 10.12442/j.issn.1002-185X.20250166Abstract:
Porous CoCrNi medium-entropy alloy (MEA) with porosity of 60.6%–78.1% and pore size of 1.8–2.4 mm were prepared by powder sintering-dissolution method. Results show that the pore distribution is uniform, and the metallurgical bonding is good. The dynamic compression test results show that the material has a significant strain rate strengthening effect, and the impact resistance is the best at strain rate of 500 s–1. The yield strength increases by 52.8% (from 22.9 MPa to 35.0 MPa) with the increase in strain rate from 200 s–1 to 800 s–1. The dynamic yield strength increases by 25% compared with the quasi-static yield strength. The energy absorption value reaches 35.4–14.5 MJ/m3 (6.6%–14.0% higher than the quasi-static result), and the maximum ideal energy absorption efficiency is close to 0.9. At the same time, under the condition of low temperature (–100 ℃), the elastic modulus and platform stress are increased by 2.4%–10.5% and 2.5%–9.8%, respectively, compared with those at room temperature. The energy absorption value is 41.3–15.2 MJ/m3, which is twice that of magnesium alloy foam, and the maximum ideal energy absorption efficiency is 0.8. In summary, the porous CoCrNi MEA has both dynamic strengthening and low-temperature strengthening characteristics, and it has good energy absorption capacity and high ideal energy absorption efficiency, showing significant application potential in the field of actual working conditions and extreme environments.2026, 55(8):1917-1928. DOI: 10.12442/j.issn.1002-185X.20250397Abstract:
As a strategic critical metal, niobium is widely used in the fields of aerospace, nuclear industry, and superconductors owing to its superior properties. With the requirement of sustainable development, the energy consumption in niobium melting processes has attracted increasing attention. Green, low-carbon, and energy-saving practices have become the new development direction. In addition, microelectronics technology requires high-purity niobium as a sputtering target material. Although niobium with a purity of up to 5N has been achieved, a low-cost high-purity technique is still challenging. This review summarized a variety of pyrometallurgical methods for the preparation and purification of crude niobium. As a traditional method for producing crude niobium, the key challenge of thermal reduction is how to reduce energy consumption. As a technique with industrial propects, molten salt electrolysis has been developed into a variety of methods, but the efficiency needs to be further improved. In addition, some new purification techniques are constantly emerging, such as fully-automated melting technique assisted by the digital twin and artificial intelligence. In the future, a variety of technical means will be combined to purify niobium metal. This review also briefly introduced the current status of niobium recovery and further explored the full lifecycle of niobium based on the concept of urban mine, to provide direction for achieving niobium recycling. -
2026, 55(7):1807-1815. DOI: 10.12442/j.issn.1002-185X.20250115Abstract:
The distribution and evolution of the internal grain structure of large-scale GH4738 alloy during the complex continuous deformation cogging process, based on the process sequentiality and organizational heredity, were investigated by employing a finite element model combined with secondary development methods, providing a general approach for process design and outcome prediction. Finite element simulation calculations were conducted based on the actual billet preparation process of GH4738 superalloy with Ф660 mm grade, comparing the simulation results with the grain size at corresponding positions of the actual billets to verify the reliability and accuracy of the established model. Utilizing this model, typical upsetting and cogging processes were analyzed, and the effects of process parameters on the microstructural evolution of the billet during multiple deformation passes were discussed, along with methods for process formulation. Results show that during the upsetting process, as the upsetting speed increases, the deformation temperature decreases, the reduction amount decreases, and the degree of dynamic recrystallization within the billet decreases. In the cogging process, as the upsetting speed decreases, the cogging temperature increases, the feed amount decreases, and the degree of dynamic recrystallization within the billet increases. Furthermore, based on the specific analysis, it is recommended to control the upsetting speed during the upsetting process between 5 and 12 mm/s; the initial upsetting temperature should be 1160 °C; the single-pass reduction amount should be controlled between 25% and 35%. The cogging process is more complex than the upsetting process. Taking into account the factors such as grain refinement within the billet, surface temperature drop during the cogging process, and the occurrence of the "concave center" phenomenon, the upsetting speed is controlled between 60 and 90 mm/s; the second cogging temperature is chosen between 1120 and 1130 °C; the feed amount is controlled between 200 and 350 mm.2026, 55(7):1793-1800. DOI: 10.12442/j.issn.1002-185X.20250098Abstract:
Al-Ga-Mg-Sn soluble aluminum alloy was selected for a one-step hydrometallurgical technique. Acid leaching agents, including organic acid solutions (e.g., oxalic, malic, and acetic solutions) and inorganic acid solutions (e.g., nitric acid) were used. The type of leaching agent, pH value, temperature, and solution concentration are key factors influencing the recovery of Ga during hydrogen production. Recovery results show that under the temperature of 70 ℃ and the agent concentration of 0.2 mol·L–1, the organic acid solution successfully recovers gallium, with oxalic acid exhibiting the highest recovery efficiency (86.88%), followed by malic acid (73.40%) and acetic acid (13.17%). In contrast, the inorganic acid (nitric acid) solution fails to recover gallium. Oxalic acid, with an initial pH value of approximately 3.8, achieves a recovery efficiency of 94.38% under 70 °C/0.3 mol·L–1 and 93.78% under 90 °C/0.2 mol·L–1. The leaching behavior of gallium was then tested and analyzed based on changes in pH value, shape of the recovered gallium, solid particle size and Zeta potential of the product during the hydrolysis process. The results show that the recovery of gallium from oxalic acid leachate increases with the decrease in particle size of the product and increase in absolute value of Zeta potential. The highest recovery efficiency (94.38%) is achieved with a product particle size of 155 nm and a Zeta potential value of –31.29 mV.2026, 55(7):1692-1700. DOI: 10.12442/j.issn.1002-185X.20250326Abstract:
Tensile mechanical tests at room temperature with varying strain rates (0.001, 0.01, and 0.07 s-1) were conducted on Cu tubes (as-processed state), Nb tubes (soft state), and Mg rods (extruded state) used for internal magnesium diffusion (IMD)-MgB2 single-core wires. Uniaxial unidirectional mechanical tests and cyclic compression mechanical tests at room temperature were performed on B powder to obtain the stress-strain curves. Based on the abovementioned analysis results, Johnson-Cook constitutive models for three metals at room temperature were established, as well as the function between the elastic modulus of B powder and its relative density. Furthermore, the bulk deformation of IMD-MgB2 single-core wires during room-temperature rolling was simulated using the DEFORM finite element software, and the deformation behavior and stress distribution of materials were analyzed. Results demonstrate that the Johnson-Cook models established for three metals and the elastic modulus-relative density function of B powder accurately describe the flow behavior of Cu, Nb, and Mg in IMD-MgB2 wires, as well as the elastic deformation of B powder. DEFORM finite element simulation results can also effectively reflect the deformation behavior of IMD-MgB2 single-core wires. The overall deformation during the rolling process is uniform with a homogeneous stress distribution; however, the surface still has defects. This study provides a theoretical basis for optimizing the plastic forming process of IMD-MgB2 superconducting wires.2026, 55(7):1651-1663. DOI: 10.12442/j.issn.1002-185X.20250404Abstract:
Micro/nano-structured composite coating composed of titanium dioxide (TiO2) and hydroxyapatite (HA) was fabricated on TA2 pure titanium through synergistic micro-arc oxidation (MAO) and hydrothermal (HT) processing to enhance the corrosion resistance and biocompatibility of titanium substrates. The surface micromorphology of the coatings was investigated by scanning electron microscope; the roughness and hydrophilicity of the coatings were investigated by atomic force microscope and water contact angle, respectively; the corrosion resistance was evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization tests in simulated human body fluids; the biocompatibility was investigated by in-vitro cell culture experiments. Results demonstrate that by doping HA into MAO electrolyte, a micrometer-sized coating loaded with nano-HA particles can be obtained, and then HT treatment can be conducted to obtain the micro/nano-structured composite coating with a HA-containing nanoflake structure. This micro/nano-structured composite coating possesses good hydrophilicity and fine corrosion resistance. The coating performance achieves optimal state when the coating is prepared with 3 g/L HA and HT-treated for 6 h. In this case, the water contact angle is as low as 24.2°, and the polarization resistance is as high as 2.467×104 Ω·cm2. In addition, the synergistic effect of nano-HA and micro/nano-structure on the coating surface greatly promotes the cell proliferation, presenting non-cytotoxic characteristic, and indicating that the coating possesses good biocompatibility. -
2026, 55(6):1612-1624. DOI: 10.12442/j.issn.1002-185X.20250103Abstract:
High-purity molybdenum powder, owing to its excellent high-temperature mechanical properties, electrical and thermal conductivity, and corrosion resistance, has been widely applied in aerospace, electronic devices, nuclear energy, and powder metallurgy. This paper systematically reviewed the preparation methods of high-purity molybdenum powder, including hydrogen reduction, carbothermal reduction, spray pyrolysis, and low-temperature molten salt-assisted reduction. The effects of different preparation techniques on the purity, particle size distribution, morphological evolution, and sintering performance of molybdenum powder were analyzed. Among existing methods, hydrogen reduction is extensively applied, and research suggests that tuning reduction conditions can significantly influence impurity removal and morphological consistency. Additionally, emerging techniques, such as spray pyrolysis and low-temperature molten salt-assisted reduction, exhibit promising potential in particle size control, spheroidization, and nanostructuring, thereby enhancing powder flowability and sintering densification. Future research should further optimize precursor selection and process parameters to enhance the purity, particle size uniformity, and morphological control of molybdenum powder, meeting the growing demand for high-performance molybdenum materials in advanced manufacturing.2026, 55(6):1451-1464. DOI: 10.12442/j.issn.1002-185X.20250309Abstract:
NiTi shape-memory alloys are extensively used across various fields due to their distinctive shape-memory effect and superelasticity. Additive manufacturing technique enables the precise fabrication of high-performance complex structures of NiTi shape-memory alloys, facilitating innovative structural designs. This paper reviewed the applications of NiTi porous structures prepared by selective laser melting (SLM) in the fields of biomedical and mechanical engineering. It summarized the characteristics of various novel porous structures of SLM-NiTi across various applications, explored innovative design methodologies for these structures, and discussed their corresponding advantageous properties, which include compressive performance, superelasticity, shape-memory effect, energy absorption capability, and biocompatibility. These design methodologies and structures can provide references for the design and application of high-performance NiTi structures prepared by additive manufacturing.2026, 55(6):1419-1428. DOI: 10.12442/j.issn.1002-185X.20250248Abstract:
Waspaloy alloy is widely used in aerospace applications, particularly in gas turbines operating under extreme service conditions. The effects of solid solution duration and temperature on the microstructure and mechanical properties of a Waspaloy low-pressure turbine (LPT) case in in-service aero-engines were investigated via on-site metallographic replication techniques and laboratory verification tests. The results show that excessive solid solution treatment (1010 °C/11 h) has no adverse impact on the microstructure or grain size of the LPT cases. The alloy exhibits low sensitivity to solid solution duration. As the solid solution duration is prolonged from 4 h to 20 h, the grain size remains unchanged, and the grain morphology remains essentially consistent. Only a gradual decrease in the number of twins in the microstructure and a gradual increase in proportion of fine strengthening phases are observed. In contrast, the alloy is highly sensitive to solid solution temperature. When the solid solution temperature increases from 1010 °C to 1040 and 1070 °C, the grain size increases from Grade 7.5 to Grade 6.5 and to grade 3.0, respectively. Simultaneously, the primary strengthening phases within austenite grains are fully replaced by secondary ones. Additionally, M23C6 carbides at γ phase grain boundaries transition from isolated island-like morphologies (at low temperature) to elongated strip-like morphologies (at high temperature). Simultaneously, both the quantity and size of the intragranular MC carbides significantly increase. The microhardness and mechanical properties of the alloy are predominantly governed by the scale of strengthening phases and grain size. With the prolongation of solid solution duration, the microhardness, tensile strength, and yield strength progressively increase. However, as the solid solution temperature rises, these properties increase first and then decrease.2026, 55(6):1385-1392. DOI: 10.12442/j.issn.1002-185X.20250266Abstract:
Underwater local dry laser cladding (ULDLC) is a key technique for in-situ repair of nuclear power equipment. In this study, an underwater laser remelting technique was proposed to further enhance the wear resistance of duplex stainless steel (DSS) coatings prepared by ULDLC. The effects of laser remelting heat input on the microstructure and wear resistance of DSS coating prepared by ULDLC were investigated. Results indicate that the microstructure of DSS coatings consists of Widmanst?tten austenite (WA), intergranular austenite (IGA), grain boundary austenite, secondary austenite (γ2), and ferrite. With the increase in laser remelting heat input, the content of IGA and WA gradually decreases, while the ferrite content increases. After laser remelting, γ2 is eliminated and the grain morphology of ferrite is transformed from flaky to equiaxed. Under optimal laser remelting parameters (a laser power of 3 kW, a laser spot diameter of 6 mm, and a laser scanning speed of 10 mm/s), the microhardness of remelted zone is 318.7 HV, which is increased by 25.7 HV, the friction coefficient decreases by 32%, and the wear volume is reduced by 55%. The significantly improved wear resistance is attributed to the synergistic effects of surface oxide-layer formation and ferrite grain refinement. -
2026, 55(5):1374-1384. DOI: 10.12442/j.issn.1002-185X.20250279Abstract:
The structural materials of space nuclear reactors need to withstand extreme service environments such as high temperature and high-flux neutron irradiation, and their performance greatly affects the safety and economy of reactor operation. This paper focuses on the irradiation damage behavior of Mo-Re alloys used in space nuclear reactors, reviews irradiation damage effects, microstructure evolution caused by irradiation, and degradation of service performance. It provides a theoretical basis for the microstructure optimization, performance prediction, and service life evaluation of Mo-Re alloys as reactor materials.2026, 55(5):1363-1373. DOI: 10.12442/j.issn.1002-185X.20240791Abstract:
Superalloys, serving as the critical materials for hot-end components like turbine blades, combustion chambers, and turbine disks, are widely used in aviation, aerospace, and energy sectors due to their excellent performance in high-temperature environments. However, controlling the microstructure of superalloys remains a significant challenge in actual production. Radial forging, with its high efficiency, high material utilization, and significant improvement of the microstructure of forgings, shows great potential in the production of superalloy materials. Through multiple hammers and high-frequency forging, radial forging achieves uniform deformation of the billets, enhancing the mechanical properties and internal density of the forgings. This paper systematically elaborates on the driving principles of radial forging equipment and the influence of key process parameters on the production process. It analyzes the microstructure evolution mechanism and grain growth behavior of superalloys under multi-pass high-frequency forging, compares the applicability of different forging penetration models, and summarizes the current research status of stress-strain constitutive models and microstructure evolution models in finite element simulation. This review also points out that high-precision multi-physics coupled simulation and intelligent process design are the core directions for future development.2026, 55(5):1348-1362. DOI: 10.12442/j.issn.1002-185X.20240849Abstract:
The pre-processing module is a core component of casting numerical simulation software, directly influencing the accuracy and efficiency of simulations. This paper presented a comprehensive review of pre-processing techniques in casting simulation, with a specific focus on geometric modeling, parameter configuration, and the pivotal mesh generation techniques. The principles and evolutionary history of hexahedral, tetrahedral, and hybrid meshing methods were elaborated. Furthermore, the strengths and limitations of various algorithms in handling complex castings were analyzed. Finally, the paper identified key challenges currently facing pre-processing modules and outlined future development trends.2026, 55(5):1334-1347. DOI: 10.12442/j.issn.1002-185X.20250234Abstract:
Metal additive manufacturing, characterized by its point-by-point and layer-by-layer forming process, enables the efficient and precise fabrication of complex structural components that are difficult to produce with traditional manufacturing techniques. However, the metal additive manufacturing process involves large temperature gradients and rapid cooling rates, constituting a highly non-equilibrium process that may lead to crack formation within the solidified microstructure, thereby influencing the mechanical properties of the material. Consequently, the control of solidification microstructure during metal additive manufacturing is pivotal for designing materials with superior mechanical properties. The solidification microstructure selection map serves as a tool that establishes a mapping relationship between composition/process parameters (used as both horizontal and vertical axes) and solidification microstructure, enabling the prediction and regulation of solidification microstructures in metal additive manufacturing processes. This review provided a comprehensive summary of the current types of solidification microstructure selection maps, outlined their construction methodologies, and summarized the applications of various solidification microstructure selection maps in metal additive manufacturing processes for recent years. Lastly, this review offered insights into the prospects of solidification microstructure selection maps in terms of novel types, innovative construction approaches, and potential application values.2026, 55(5):1317-1333. DOI: 10.12442/j.issn.1002-185X.20250226Abstract:
With the rapid advancement of electronic devices towards miniaturization, high integration, and multifunctionality, the complexity of chip packaging has increased significantly. As packaging density continues to rise and solder joint size decreases, the operating conditions of electronic components in service become increasingly demanding. Consequently, the reliability of micro-interconnect solder joints has become a critical concern, with solder joint failure emerging as one of the key bottlenecks hindering the further development of electronic packaging techniques. This paper focuses on the failure behavior of micro-interconnect solder joints and reviews several common reliability issues in electronic packaging. Based on the selection of different phase-field variables, several typical phase-field modeling approaches are summarized. Furthermore, the paper analyzes the application and current progress of phase-field methods in simulating several representative failure modes, such as electromigration, through-silicon vias (TSVs), and interfacial intermetallic compound (IMC) growth. Finally, the potential of phase-field modeling in studying micro-scale failure mechanisms is discussed, along with its future development trends in multi-physics coupling, data-driven modeling, and engineering applications. This work aims to provide systematic references and methodological support for both theoretical analysis and practical engineering studies on the failure behavior of micro-interconnect solder joints.2026, 55(5):1308-1316. DOI: 10.12442/j.issn.1002-185X.20250232Abstract:
With the rapid development of the aviation industry, superalloys and titanium-based alloys serve as core materials for aerospace engines and structural components, whose microstructure control and performance optimization are key factors to ensure equipment reliability. The mechanically-coupled phase-field model, as an effective tool for simulating microstructure evolution, bridges the gap among microscale mechanical principles, mesoscale microstructure simulation and macroscopic performance predictions. The model reveals the intrinsic connection between microstructure evolution and mechanical properties of materials in thermomechanical coupled field, providing theoretical support for the microstructure control and performance evaluation of aerospace materials. This paper systematically reviewed the research progress on mechanically-coupled phase-field models in the fields of typical aerospace materials, such as superalloys and titanium-based alloys. It outlined typical application cases of the model in investigating the mechanisms of solid-state phase transformation. This review encompassed applications of phase-field models from elastic and elastoplastic to defect-coupled formulations, addressing both γ′ phase precipitation and rafting in superalloys, as well as the evolution of precipitate phases in titanium-based alloys. Furthermore, it discussed the challenges in current research and provided an outlook on the future prospects of the mechanically-coupled phase-field model in aerospace material research. Lastly, it highlighted the key issues of this type of phase-field model and its future development directions. -
2026, 55(4):1115-1128. DOI: 10.12442/j.issn.1002-185X.20250217Abstract:
Titanium matrix composites (TMCs), owing to their high specific strength and high specific modulus, hold great promise for applications in load-bearing aerospace components. However, the strength-ductility trade-off at room temperature significantly restricts their widespread use. The hetero-deformation induced (HDI) hardening effect in heterogeneous structured materials offers a new approach to overcoming the strength-toughness trade-off bottleneck in TMCs. The recent advances in heterogeneous structured titanium and titanium alloys were outlined, then the current research status and compositing strategies of TMCs were summarized and discussed. The failure mechanisms of homogeneous TMCs were elucidated, and the latest developments in configuration and heterostructure design by the pinning effects of reinforcement phases were highlighted. Taking the "hard-in-soft" network structures and "soft-in-hard" granular structures as examples, this work reviewed the design concepts, fabrication methods, classification, and strengthening mechanisms of heterogeneous structured TMCs, providing insights and references for the development of TMCs with a well-balanced strength-ductility relationship.2026, 55(4):1102-1114. DOI: 10.12442/j.issn.1002-185X.20250345Abstract:
Ti-6Al-4V alloy is widely used in aerospace, biomedical, and other fields due to its excellent specific strength, corrosion resistance, and biocompatibility. However, rapid solidification and complex thermal cycling during additive manufacturing often lead to the formation of coarse columnar β grains in titanium alloys, resulting in anisotropic mechanical properties and reduced fatigue performance. Achieving equiaxed microstructure control is crucial for improving the comprehensive properties of additively manufactured titanium alloys. This work reviewed recent advances in achieving equiaxed microstructures of Ti-6Al-4V (TC4) alloy through microalloying, composite fabrication, external field assistance, and heat treatment. The influence mechanisms of α-stabilizing elements, β-stabilizing elements, external field-assisted techniques, and heat treatment processes on the microstructure and mechanical properties of Ti-6Al-4V alloy were discussed. Furthermore, future research directions were outlined, focusing on precise microstructure control, process parameter optimization, and the development of high-performance titanium alloys. The aim of this work is to provide theoretical guidance and technical support for microstructure optimization and performance enhancement of additively manufactured titanium alloys.2026, 55(4):1013-1018. DOI: 10.12442/j.issn.1002-185X.20250181Abstract:
The white blocks of TB18 high Mo equivalent metastable β ultra-high strength and toughness titanium alloy were studied. The alloy which was forged in the two-phase region and then solid solution and aging treatment in β region. The formation mechanism and elimination methods of white blocks were analyzed by mechanical property testing, microstructure observation, and further heat treatment experiments. The results indicate that the white blocks in TB18 titanium alloy are β matrix without any precipitation of α phase, with low hardness, high plasticity, and high impact toughness. The reason for the formation of white blocks is not related to the distribution of β-stable elements in the alloy, but mainly caused by the forging process. White blocks can be weakened or eliminated from the macroscopic structure by optimizing forging or heat treatment processes, such as increasing solubility, pre-aging, and extending aging time. However, from a more detailed microstructure analysis, the white blocks in TB18 titanium alloy cannot be completely eliminated but can only be reduced in size, which is determined by the characteristics of the TB18 alloy. The results of this study have a fundamental guiding role in improving the preparation process and optimizing the microstructure of TB18 alloy, and also produce important reference significance for the microstructure and performance analysis of similar alloys.2026, 55(4):950-958. DOI: 10.12442/j.issn.1002-185X.20240804Abstract:
A systematical analysis of the macrostructure, microstructure, composition, and crystal orientation of the bright-band defect was conducted by OM, SEM, and EBSD methods, as well as Gleeble tests, and the formation mechanism of bright-band defect of forged TC18 alloy was studied. The results show that the bright-band defects in the center of TC18 alloy forging stocks correspond to β cube-grains with the size of around 100 mm. During the forging process, an inhomogeneous distribution of temperature and equivalent strain in the forging stocks is caused by adiabatic heating, which is an important reason for the microstructural heterogeneity. The large β cube-grains are formed due to the repeated compression along the orthogonal direction, which results in continuous strengthening of the <100> texture in the center of the forging stocks, and the merging of <100> grains with similar orientations. Through annealing treatment and compression along diagonal direction, it is possible to effectively reduce and avoid bright-band defects in TC18 alloy.2026, 55(4):841-855. DOI: 10.12442/j.issn.1002-185X.20250284Abstract:
To investigate the effect of solution treatment and aging process parameters on the microstructure and mechanical properties of TB18 titanium alloy, process optimization research was conducted based on the mixed-level orthogonal experiment design of factor levels. Results show that through range analysis, the significance order of process parameters is determined as follows: solution cooling method>solution temperature>aging time>aging temperature>solution time. Considering the strength-ductility matching and engineering application requirements, the benchmark parameters are selected as solution time of 1 h, solution cooling method of air cooling (AC), aging temperature of 525 °C, and aging time of 4 h. Furthermore, the effects of solution temperature in the range of 790–870 °C on the impact toughness and micro-fracture characteristics of the alloy were studied. The results reveal that the larger the area of shear lip and fibrous zone, and the smaller the area of radiation zone, the better the toughness of the alloy. With the increase in solution temperature, the length of secondary cracks on the fracture surface increases, the number of dimples increases, and the toughness is enhanced. Based on the collaborative optimization of strength and toughness, the optimal heat treatment process for TB18 alloy is determined as 870 °C/1 h, AC+525 °C/4 h, AC. -
Research Progress on Coordinated Deformation of Superconducting Wires Based on Finite Element Method
2026, 55(3):830-840. DOI: 10.12442/j.issn.1002-185X.20250077Abstract:
The structures of NbTi, Nb3Sn, MgB2, and Bi-based superconducting materials are complex. The uniformity of coordinated deformation among metals, between metals and powders, and within core wires determines the processing quality and mechanical properties of wires. The structures of wires and dies, processing parameters, and deformation conditions are important factors affecting their coordinated deformation behavior. The finite element numerical simulation method is an important engineering tool for analyzing and evaluating the coordinated deformation behavior of superconducting wires under multiple factors. This approach can accurately and intuitively simulate the coordinated rheological behavior during the forming process of multi-layer and multifilament composite superconducting wires, as well as the stress/strain distribution among composite phases and their interfaces. This review summarizes recent progress in finite element simulation of superconducting wire forming. It covers the establishment of finite element models, selection of constitutive models, and setting of boundary conditions for superconducting wire forming. At the same time, the review discusses the affecting mechanism of deformation parameters, die structure, and processing technique on coordinated deformation behavior, as well as recent advances in multi-scale analysis.2026, 55(3):808-829. DOI: 10.12442/j.issn.1002-185X.20250206Abstract:
Tantalum, as a high-performance biometallic material with bioaffinity, is widely used in bone structure reconstruction and bone function repair. Porous tantalum exhibits excellent mechanical properties, biological properties, as well as in vivo osseointegration and bone ingrowth performance, showing outstanding clinical treatment effectiveness. This review based on recent research of our team and combined with literature analysis, reviewed the latest research progress in additive manufactured porous tantalum materials, including fabrication processes, structural design and optimization, mechanical properties, biological properties (cell-material interactions), in vivo osseointegration and bone ingrowth capabilities, and clinical applications. In particular, additive manufactured porous tantalum materials and orthopedic implants allow for the precise design and regulation of three-dimensional interconnected biomimetic porous structures, excellent static and dynamic mechanical properties, and bone conduction and bonding abilities. These materials are easy to manufacture anatomically matched personalized products, with promising applications in the repair of bone defects and the treatment of bone diseases.2026, 55(3):798-807. DOI: 10.12442/j.issn.1002-185X.20250289Abstract:
To meet the growing demand for enhanced material properties of aero-engines, the alloying element content of wrought superalloys is increasing, which leads to the difficulty of ingot casting. Excessive addition of alloying elements in superalloys tend to induce cracking under the combined action of thermal stress and phase transformation stress. Once cracks occur, it will not only interfere with the stability of process parameters such as current and voltage in the subsequent remelting process, but also raise scrap rate of the ingot, and exert an irreversible impact on the performance and reliability of the final product. Cracks in ingot, as a complex metallurgical defect during superalloy casting, has become a critical technological bottleneck, restricting the size scaling of high-alloyed superalloy ingots. Then, this paper reviews the recent research progress on the causes of cracking in wrought superalloy ingots during triple-melting processes, as well as various influencing factors in crack formation. Corresponding inhibition measures are also proposed for different cracking causes. The research direction of ingot cracking is prospected, aiming to provide a theoretical basis and technical reference for producing defect-free superalloy materials.2026, 55(3):655-664. DOI: 10.12442/j.issn.1002-185X.20250176Abstract:
The multi-principal element characteristic of high-entropy alloys has revolutionized the conventional alloy design concept of single-principal element, endowing them with excellent mechanical properties. However, owing to this multi-principal element nature, high-entropy alloys exhibit complex deformation behavior dominated by alternating and coupled deformation mechanisms. Therefore, elucidating these intricate deformation mechanisms remains a key challenge in current research. Neutron diffraction (ND) techniques offer distinct advantages over traditional microscopic methods for characterizing such complex deformation behavior. The strong penetration capability of neutrons enables in-situ, real-time, and non-destructive detection of structural evolution in most centimeter-level bulk samples under complex environments, and ND allows precise characterization of lattice site occupations for light elements, such as C and O, and neighboring elements. This review discussed the principles of ND, experiment procedures, and data analysis. Combining with recent advances in the research about face-centered cubic high-entropy alloy, typical examples of using ND to investigate the deformation behavior were summarized, ultimately revealing deformation mechanisms dominated by dislocations, stacking faults, twinning, and phase transformations.2026, 55(3):636-654. DOI: 10.12442/j.issn.1002-185X.20250140Abstract:
Graphene/copper-based composite heat sinks demonstrate extensive application potential in military equipment thermal management, high-power electronic packaging, new energy vehicles, and 5G communication systems, due to their outstanding properties, including high thermal conductivity, tunable thermal expansion coefficients, excellent mechanical strength, and low density. However, the industrial-scale application of these composites faces critical challenges during the fabrication of components with complex structures, such as inhomogeneous dispersion of graphene within the copper matrix and poor interfacial bonding between the two phases, which substantially undermine the overall performance of graphene/copper-based composites. To address these issues, the preparation methods for graphene/copper-based composite heat sinks were reviewed. For each method, a rigorous analysis was presented to clarify its inherent advantages and unavoidable restrictions. Furthermore, the latest research progress in addressing three core scientific challenges was synthesized, including uniform dispersion of graphene, interfacial optimization mechanisms, and molecular dynamics simulations for elucidating the structure-property relationships. Finally, the future development directions of graphene/copper-based composite heat sinks in engineering applications were prospected. -
2026, 55(2):558-572. DOI: 10.12442/j.issn.1002-185X.20240724Abstract:
In recent years, clean nuclear energy has developed rapidly. Zr alloys are commonly used as fuel element cladding materials in water-cooled nuclear reactions due to their good corrosion resistance and low neutron absorption cross-section. The nuclear fuel is usually sealed in a Zr alloy envelope by welding, so its weld quality is particularly critical. The high heat input of traditional fusion welding leads to large deformation, and the porosity and intermetallic compounds (IMCs) in the brazing process tend to damage the joint performance, and low-temperature diffusion bonding of Zr alloys can avoid the above problems. Therefore, this paper analyzed the weldability of Zr and its alloys, reviewed the research status of their welding technologies including fusion welding, brazing, and diffusion bonding, briefly introduced two kinds of pre-welding optimization methods, namely surface mechanical attrition treatment (SMAT) and thermo-hydrogen processing (THP). Finally, it summarized and prospected the applications in low-temperature diffusion bonding of Zr alloys.2026, 55(2):543-557. DOI: 10.12442/j.issn.1002-185X.20250327Abstract:
The development of additive manufacturing (AM) has brought innovative opportunities for the precision forming of high-melting-point refractory metals (such as tungsten, molybdenum, tantalum, niobium, and their alloys). However, due to the inherent properties of refractory metals such as high melting point, their AM processes exhibit significant particularities different from those of other metal materials. Based on the metal powder bed fusion (PBF) AM techniques represented by selective laser melting (SLM) and selective electron beam melting (SEBM), this paper systematically reviewed the research progress of tungsten, molybdenum, tantalum, niobium, and their alloys in AM field. The research focused on the powder preparation technique of refractory metals, as well as the microstructure regulation strategies of typical process defects (such as pore, cracking, grain coarsening) during the forming process and mechanical properties of these alloys. In addition, this paper also summarized the key faced in the industrialization process of refractory metals prepared by AM and prospected the future development trends.2026, 55(2):365-388. DOI: 10.12442/j.issn.1002-185X.20250078Abstract:
Soft magnetic alloys are extensively used in various power electronic devices due to their advantageous properties, including high saturation magnetic induction, low coercivity, and high permeability. In certain applications, complex-shaped components are increasingly required for performance enhancement. Additive manufacturing technique, particularly selective laser melting (SLM), has emerged as an effective method for fabricating such complex-shaped soft magnetic components. SLM, a laser-based additive manufacturing technique, employs high-power-density lasers to melt and fuse metal powders within a powder bed selectively. This approach enables rapid prototyping, precise geometrical control, and the integration of multi-material designs. This review highlights recent advancements in the application of SLM technique for the production of soft magnetic alloys, focusing on Fe-Si, Fe-Ni, Fe-Co, and amorphous alloy systems. Moreover, it explores the implementation of SLM in manufacturing processes and evaluates both the opportunities and challenges associated with SLM-based production of soft magnetic alloys.2026, 55(2):333-344. DOI: 10.12442/j.issn.1002-185X.20240524Abstract:
Platinum group metals have high melting points, strong corrosion resistance, stable chemical properties, and low oxygen permeability in high-temperature oxygen-containing environments. As thermal protective coating materials, they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields, such as protecting hot-end components of hypersonic aircraft. This research reviewed the latest research progress of platinum group metal coatings with high-temperature oxidation resistance, including coating preparation techniques, oxidation failure, and alloying modification. The leading preparation techniques of current platinum group metal coatings were discussed, as well as the advantages and disadvantages of various existing preparation techniques. Besides, the intrinsic properties, failure forms, and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed. On this basis, the necessity, main methods, and main achievements of alloying modification of platinum group metals were summarized. Finally, the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected. -
2026, 55(1):278-284. DOI: 10.12442/j.issn.1002-185X.20240592Abstract:
In the field of superconducting materials research, from the discovery of elemental mercury as a superconductor to the preparation of nickel-based superconductors, the study on physical properties and microscopic mechanisms of superconducting materials has greatly promoted the development of condensed matter physics. The development of practical high-temperature superconductors based on new preparation techniques plays an extremely important role in the fields of strong and weak electricity. As a new means, the high-pressure experimental technique has become one of the powerful tools for exploring novel superconductors and increasing their superconducting transition temperature (Tc). Focusing on three high-temperature superconductors with relatively high superconducting transition temperatures (exceeding 150 K), including H3S, LaH10 and HgBaCaCuO, this paper summarizes the research progress in their preparation techniques and clarifies the preparation strategies of practical high-temperature superconductors. It is concluded that high pressure facilitates the preparation of LaH10, a hydrogen-rich compound superconductor with a special crystal structure, so that it can obtain a higher superconducting transition temperature. At the same time, high pressure can also affect copper oxide superconductors in a similar way of changing doping, thereby changing their superconductivity. High pressure technique is an effective way to fabricate high-temperature superconductors with special crystal structures (layered and caged).2026, 55(1):266-277. DOI: 10.12442/j.issn.1002-185X.20240643Abstract:
Cathodic arc ablation restricts the stable operating time of arc plasma devices. Developing cathodes with long lifespan and service stability is essential for improving the operating capability of current equipment. Understanding cathodic arc ablation behavior and failure mechanisms is key to developing high-performance cathodes. This article firstly analyses the intricate arc ablation process of metallic cathodes and introduces failure mechanisms of sputtering, oxidation, and inhomogeneous ablation resulting from cathode spots. Furthermore, it reviews the recent advancements in improving cathode ablation resistance, including grain refinement, low work function addition, and gradient functionalization. In the final section, the future development of metallic cathodes is prospectively discussed based on in-situ observation of cathode spots, the construction of multi-field cathodic arc ablation model, and the establishment of a comprehensive cathode developing regime encompassing design, manufacturing, and testing processes.2026, 55(1):250-265. DOI: 10.12442/j.issn.1002-185X.20240617Abstract:
Due to their low density, good room-temperature plasticity, and excellent high-temperature toughness, refractory niobium alloys have been used in hot-end components in the aerospace field. However, niobium alloys prepared by traditional casting methods are difficult to process parts with complex geometries, and face problems such as long production time, high cost and high buy-to-fly ratio. The rapid development of additive manufacturing technique in recent years not only shortens production time and lowers cost but also achieves superior mechanical properties, presenting new opportunities for the further application of niobium alloys. To this end, this paper reviews the current state-of-the-art research on additive manufactured niobium alloys focusing on the laser and electron-beam additive manufacturing of two generations of typical niobium alloys (namely C-103 and Nb521), with specific attention to the control of their mechanical properties and microstructure. In addition, common types of niobium alloys and additive manufacturing techniques are briefly introduced. Finally, the review outlines future research directions and identifies remaining challenges for this field. By reviewing the current state of additive manufactured niobium alloys, this paper provides a reference for the further application of niobium alloys in the aerospace field for hot-end components with complex structures.2026, 55(1):193-202. DOI: 10.12442/j.issn.1002-185X.20240596Abstract:
According to the varying load in different directions, the anisotropy control of porous materials can significantly enhance the load-bearing efficiency of materials, thus better addressing the need for lightweight designs. In this research, a modified Gibson-Ashby model for strut-based porous materials accounting for geometric parameters was established by taking G7 and bccz types of TC4 porous materials as examples. This model can serve as a guide for the precise control of anisotropy for strut-based porous materials. Based on this model, a series of anisotropic porous materials with similar configurations but distinct properties were created by adjusting geometric parameters of common unit cells. The effects of unit cell geometric parameters on the anisotropic compressive strength and failure modes of porous materials were investigated through vertical and lateral compressive tests, thereby validating the efficacy of the modified model. The results show that the compressive strength of strut-based porous materials is primarily determined by the aspect ratio and the inclination angle of their struts. By fine-tuning the inclination angle of struts, the anisotropic mechanical properties of porous materials can be effectively modulated. Under the same density, increasing the inclination angle of the diagonal struts from 35° to 55° can significantly increase the vertical compressive strength of G7 and bccz types of TC4 porous materials by 105% and 45%, respectively, with only a minor reduction in lateral compressive strength of 16% and 13%, respectively.2026, 55(1):47-58. DOI: 10.12442/j.issn.1002-185X.20250065Abstract:
The key parameters that characterize the morphological quality of multi-layer and multi-pass metal laser deposited parts are the surface roughness and the error between the actual printing height and the theoretical model height. The Taguchi method was employed to establish the correlations between process parameter combinations and multi-objective characterization of metal deposition morphology (height error and roughness). Results show that using the signal-to-noise ratio and grey relational analysis, the optimal parameter combination for multi-layer and multi-pass deposition is determined as follows: laser power of 800 W, powder feeding rate of 0.3 r/min, step distance of 1.6 mm, and scanning speed of 20 mm/s. Subsequently, a Genetic Bayesian-back propagation (GB-BP) network is constructed to predict multi-objective responses. Compared with the traditional back propagation network, the GB-back propagation network improves the prediction accuracy of height error and surface roughness by 43.14% and 71.43%, respectively. This network can accurately predict the multi-objective characterization of morphological quality of multi-layer and multi-pass metal deposited parts. -
2025, 54(12):3218-3232. DOI: 10.12442/j.issn.1002-185X.20240483Abstract:
Cold spraying has great advantages in preparation of oxidization-sensitive metallic coatings because of the lower heat input and almost no oxidation resulting from its low temperature process. Combined with the convenience of cold spraying in manufacturing particle reinforced composite coatings, titanium matrix composite coatings prepared by cold spraying can compensate for the shortcomings of poor wear resistance of pure titanium or titanium alloys. In addition, one can also get the functional coatings besides the structural coatings. According to the existing research reports, the deposition behaviors and mechanisms of cold-sprayed titanium matrix composite coatings were summarized. By analyzing the porosity and deposition efficiency, the effect of reinforcement on the microstructure of the cold-sprayed titanium matrix composite coatings was explained. The mechanism of reinforcement on mechanical and wear performance of titanium matrix composite coatings were revealed. Finally, the future application of cold-sprayed titanium matrix composite coatings is prospected, and several promising directions are listed.2025, 54(12):3210-3217. DOI: 10.12442/j.issn.1002-185X.20240522Abstract:
TiAl alloys have a good application prospect in the field of high temperature structural materials due to their excellent specific strength, specific stiffness, corrosion resistance and oxidation resistance. The lamellar structure is an important microstructure of TiAl alloy, and its discontinuous coarsening behavior directly affects the comprehensive properties of the alloy. In this paper, the coarsening types of TiAl alloy lamellar structure are introduced, and the thermodynamics and kinetics of discontinuous coarsening are analyzed. Besides, the research progress of discontinuous coarsening behavior of TiAl alloys lamellar structure in recent years is reviewed. The effects of chemical composition and content, microstructure characteristics, heat treatment process (such as cyclic heat treatment cycle, temperature, time, cooling rate, etc.), additive manufacturing technology and stress on discontinuous coarsening are summarized. Finally, the future development direction of TiAl alloy lamellar structure design and optimization is prospected.2025, 54(12):3128-3138. DOI: 10.12442/j.issn.1002-185X.20240422Abstract:
Based on the diamond-type triply periodic minimal surface (D-TPMS) lattice structures, two types of TPMS lattice structure models of homogeneous and variable density were designed and prepared by the regulation method of linear gradient wall thickness and selective laser melting technology. The effects of relative density, printing direction and model type on the mechanical properties and energy absorption characteristics were analyzed, and the stress distribution and damage mechanism of the variable-density lattice structures were verified by the finite element method. The results show that the damage of the homogeneous TPMS lattice structure is 45o shear fracture, which occurs at the early stage of plastic deformation; the damage of the variable density TPMS lattice structure is interlayer collapse, and the overall structure has excellent load bearing and energy absorption capacity. When the relative density of the TPMS lattice structure is 0.275, the ultimate compressive strength of the homogeneous TPMS lattice structure is up to 193.8 MPa, the deformation amount is 7.7%, and the cumulative value of energy absorption is 11.76 MJ/m3, whereas the ultimate compressive strength of the variable-density TPMS lattice structure is up to 221.4 MPa, and the structure is still intact when the deformation amount is 50%, and the cumulative value of energy absorption is up to 77.52 MJ/m3, which is 6.59 times higher than that of the homogeneous structure. It is demonstrated that the variable-density TPMS lattice structure has good energy absorption effect and excellent load-bearing performance, which has a significant application prospect in the field of collision avoidance and energy absorption.2025, 54(12):3123-3127. DOI: 10.12442/j.issn.1002-185X.20240518Abstract:
ZrC-SiC composite matrix dispersion coated particle fuel surrogate pellets were prepared by spark plasma sintering (SPS) process. The effects of different TRISO (TRistructural ISOtropic) packing fraction on the microstructure and sintering densification process of surrogate pellets were investigated, and the distribution of TRISO particles was characterized. The results show that under the sintering conditions of 1900 ℃/ 30 MPa/10 min, dispersion coated particle fuel pellet samples with TRISO packing volume fraction up to 40%, uniform particle distribution, integral microstructure and good matrix densification can be obtained. The TRISO packing fraction has little effect on the sintering densification process of fuel pellet samples.2025, 54(12):3065-3076. DOI: 10.12442/j.issn.1002-185X.20240656Abstract:
GH4350 (AEREX 350) is a Ni-based wrought superalloy for high-performance fasteners, with a maximum service temperature of 750 °C. It has high tensile strength, fatigue resistance, stress rupture and relaxation resistance, corrosion resistance, low thermal expansion, and notch sensitivity. The high strength of GH4350 is largely derived through solid solution strengthening and the γ′ phase precipitation strengthening. During the precipitation of γ′ phase, a minor amount of η phase also precipitates. However, it is reported that the microstructure of alloy is sensitive to heat treatment parameters, including temperature and time. The γ′ phases can be transformed into η phases under certain conditions, potentially degrading the performance of the alloy. The chemical composition characteristics, heat treatment strategies, and strengthening mechanism of GH4350 were reviewed in this research, aiming to understand the factors behind its remarkable high-temperature performance, to guide the development of new alloys, and to further enhance its heat resistance. -
2025, 54(11):2964-2984. DOI: 10.12442/j.issn.1002-185X.20240461Abstract:
In the additive manufacturing process, there are melt-solidification defects in the processed components using electron beam or laser powder melting technology. The additive friction stir deposition (AFSD) based on solid-phase additive technology overcomes such defects and has been applied. During the additive process of AFSD, material melting and solidification are not involved. The deposited components with high material density and small grains have a uniform, equiaxed, and fine microstructures. Consequently, they possess good toughness and mechanical properties that can reach the forging level. Although there have been some studies on AFSD for materials such as aluminum alloy, magnesium alloy, and titanium alloy, this process is still in the early stage. Therefore, the research and application of AFSD in the recent 20 years were reviewed, which was elaborated from aspects such as principles, equipment, processes, properties, applications, and development trends, providing a reference for the research of AFSD.2025, 54(11):2949-2963. DOI: 10.12442/j.issn.1002-185X.20240661Abstract:
Cu-Ta composites with high strength, high electrical and thermal conductivity, and excellent thermal stability show promising applications in many fields, such as electrical devices, defense, rail transport, ultra-high field pulsed magnets, and biomedical engineering. Extensive studies were conducted to meet the application requirements, and significant results were achieved. This work provides a comprehensive review of recent developments in the fabrication methods, performance, and applications of Cu-Ta composites. Besides, the problems of present researches have been pointed out and development trends in future are prospected.2025, 54(11):2931-2937. DOI: 10.12442/j.issn.1002-185X.20240577Abstract:
The discrete element simulation of high-pressure torsion (HPT) deformation of W-Cu homogeneous powder material was carried out by PFC-3D software. The force chain and displacement distribution of particles during compression and torsion deformation were analyzed, and their effects on porosity, coordination number, and equivalent stress in different regions were discussed. The simulation results indicate that the particle displacement exhibits a gradient distribution along both the compression direction and radial direction, with the maximum displacement located at the sample edge and on the upper surface. During the compression stage, particle rearrangement reduces the porosity rapidly, while shear deformation further promotes secondary particle rearrangement and rotation, which leads to a gradual decrease in porosity. The relative density and coordination number at the sample edge are higher than at the center, indicating that shear deformation under large torsional radius is beneficial for powder densification. Under the conditions of 400 ℃ and 1.5 GPa, HPT deformation is applied to the cold-pressed W-30Cu powder compacts with different turns. The experimental results show that with the increase in torsional radius and HPT turns, the degree of particle breakage, microstructure refinement, and homogeneity are improved significantly. Under the combined effect of high hydrostatic pressure and shear force, the pores are elongated and enclosed, which results in increased relative density from (95.44±0.87)% (after 10 turns) to (96.03±0.54)% (after 20 turns). The crystallite size of tungsten significantly reduces to 20.8 nm and the dislocation density rapidly increases to 2.35×1014 m-2 after 15 turns; the grain refinement and dislocation accumulation achieve the dynamic equilibrium. After 20 turns, due to the combined effects of powder densification, microstructure refinement, and dislocation accumulation, the microhardness at the samples edge reaches (334.8±4.2) HV, which represents an increment of approximately 78.7% compared to the sample center after 10 turns.2025, 54(11):2833-2843. DOI: 10.12442/j.issn.1002-185X.20240327Abstract:
The thermal simulation compression experiments were conducted on forged TA16 titanium alloy using the Gleeble-3800 system at the temperature of 730–1030 ℃ and strain rates from 0.1 s–1 to 10 s–1. The true stress-true strain curves of TA16 alloy under these deformation conditions were obtained. Constitutive models for the TA16 alloy were established using three different methods: the Arrhenius model, the Johnson-Cook model, and artificial neural networks (ANN). The model errors were analyzed. The results indicate that the TA16 alloy reaches a dynamic balance between work hardening and softening after yielding at medium and low strain rates. At high strain rates, it initially softens and then enters a balance state, demonstrating good workability. The mean absolute percentage error (MAPE) of the constitutive models for the TA16 alloy using the Arrhenius model, the Johnson-Cook model, and ANN is 11.49%, 23.7%, and 1.69%, respectively. The ANN model shows an order of magnitude higher accuracy compared to the traditional constitutive models. The Arrhenius model exhibits better accuracy at medium and high strain rates and in the medium and low strain range, making it practical for engineering applications. The Johnson-Cook model reflects the trend of high-strain hardening and struggles to describe the dynamic equilibrium state after yielding for the TA16 alloy, resulting in poor model accuracy and making it unsuitable for engineering applications. The ANN model demonstrates extremely high predictive accuracy across the entire range of experimental parameters, and it also maintains good accuracy for data predictions beyond the experimental parameter ranges, providing a highly accurate constitutive model for engineering applications.2025, 54(11):2802-2808. DOI: 10.12442/j.issn.1002-185X.20240569Abstract:
Flux-coated brazing and soldering material is a type of material-saving and emission-reducing composite material in recent years, which is the representative product of the development of brazing and soldering technology, which is highly concerned by welding researchers worldwide. This work mainly reviewed the research reports on the design, preparation technology, and application of flux-coated brazing and soldering materials, put forward the shortcomings of current research, and proposed the future research directions mainly focusing on the standards, the synergistic reaction mechanism between flux and metals, the alloying, and the morphology of flux-coated brazing and soldering materials in order to provide reference information and theoretical guidance for related research and technological development in the field of welding. -
2025, 54(10):2671-2683. DOI: 10.12442/j.issn.1002-185X.20240295Abstract:
Superconducting materials have broad application prospects in multiple fields, thus attracting global researchers to invest in them since their inception. Superconductive connection is a crucial part of the application of superconducting tapes and is also a component of forming persistent mode joints. However, superconducting joints currently have shortcomings in critical parameters, preparation difficulty, environmental impact, and other aspects. Therefore, scholars are constantly innovating and optimizing process methods. The structure of superconducting joints and the preparation methods and performance of four common types of superconducting material joints in recent years were introduced. The shortcomings and defects were summarized, and the future development of superconducting joints was analyzed, providing reference for the development of superconducting joints.2025, 54(10):2599-2606. DOI: 10.12442/j.issn.1002-185X.20240300Abstract:
The microstructure and properties of the novel GH4198 alloy were studied under various solution heat treatment regimes using advanced characterization techniques such as electron probe microanalysis, metallographic microscopy, and field emission scanning electron microscope. The results indicate that as the solution temperature increases from 1100 °C to 1150 °C, the primary γ' phase dissolves into the matrix, the grain size increases from ASTM 9.5 to 3, and the size of the secondary γ' phase increases. The tensile properties are greatly affected by the solution temperature: the optimum tensile strength is obtained at 850 °C and low-temperature tensile strength drops when the solution temperature increases from 1120 °C to 1140 °C. At the sub-solvus temperature of 1120 °C, as the solution cooling rate increases from 10 °C/min to 450 °C/min, the volume fraction and the size of the primary γ' phase remain unchanged, the size of the secondary γ' phase decreases, and the microhardness increases. The possible explanations for the improvement of mechanical properties are also discussed.2025, 54(10):2533-2540. DOI: 10.12442/j.issn.1002-185X.20240248Abstract:
To study the influence of microporous layer (MPL) on the surface contact and transmission characteristics of titanium felt porous transport layer (PTL), the MPL was prepared by vacuum sintering after the surface of titanium felts with 0.25 mm, 0.4 mm and 0.6 mm in thickness were filled with titanium powder. The surface contact area/resistance, pore size distribution and polarization curve of electrolytic water measured by laser scanning confocal microscope, mercury porosimetry and electrolysis cell, respectively. The results show that the effective contact area of the PTLs with MPL increase from 3.1% to 11.2%, 22.8% and 4.8% compared with that of titanium fiber felt. In addition, the contact resistances decrease to 7.07, 5.26 and 7.86 mΩ·cm2 at the contact pressure of 1.5 MPa. The pore size distribution changes from the bimodal structure of PTL to the trimodal structure of PTL with MPL. The addition of a small pore size channel of 6–32 μm is conducive to liquid water transmissions; meanwhile, medium & large pore size channels are beneficial to gas phase transmission. The overpotential of the different thickness PTLs with MPL decrease by 12 mV, 45 mV and 32 mV at current density of 2 A/cm2. In this case, the contact resistance is the lowest, the pore size distribution is uniform, and the electrolysis efficiency of porous transport layer with 0.4 mm in thickness is the highest.2025, 54(10):2509-2524. DOI: 10.12442/j.issn.1002-185X.20250303Abstract:
Using the slurry reaction sintering process to prepare Hf-Ta-Si composite coating on Ta12W alloy surface, the effect of Si content on the in-situ formation mechanism of the Hf-Ta-Si coating was investigated. Results show that 30Hf:70Si coatings exhibit inferior surface uniformity with some pores. The upper part of the sample displays a four-layer gradient structure: the outermost layer is primarily composed of HfSi and HfC, the middle layer consists of (Ta, Hf)5Si3 solid solution, the lower main-layer consists of TaSi2, and the coating/substrate interface layer is Ta5Si3. However, the flow of molten Si under gravity leads to Si-enrichment on the lower part of the coating. After optimizing the Hf:Si ratio to 40:60, the gradient differences in elemental distribution on the coating surface decrease. The surface layer is dominated by HfSi/HfC, but the precipitation of HfC becomes more uniform. The continuity of the (Ta, Hf)5Si3 solid solution in middle layer is enhanced, whereas the lower layer and the interface transition layer remain unchanged. Overall, a denser multi-layer gradient structure is formed with improved surface uniformity. Additionally, the acid-alcohol resin in the organic solvent suffers high-temperature pyrolysis and in-situ reacts with Hf to generate the ultra-high-temperature ceramic HfC. This phenomenon is expected to enhance the oxidation resistance and high-temperature stability of coating.2025, 54(10):2470-2482. DOI: 10.12442/j.issn.1002-185X.20240530Abstract:
To address the issues of low accuracy, long time consumption, and high cost of the traditional temperature prediction methods for laser directed energy deposition (LDED), a machine learning model combined with numerical simulation was proposed to predict the temperature during LDED. A finite element (FE) thermal analysis model was established. The model's accuracy was verified through in-situ monitoring experiments, and a basic database for the predictive model was obtained based on FE simulations. Temperature prediction was performed using a generalized regression neural network (GRNN). To reduce dependence on human experience during GRNN parameter tuning and to enhance model prediction performance, an improved adaptive step-size fruit fly optimization algorithm (ASSFOA) was introduced. Finally, the prediction performance of ASSFOA-GRNN model was compared with that of back-propagation neural network model, GRNN model, and fruit fly optimization algorithm (FOA)-GRNN model. The evaluation metrics included the root mean square error (RMSE), mean absolute error (MAE), coefficient of determination (R2), training time, and prediction time. Results show that the ASSFOA-GRNN model exhibits optimal performance regarding RMSE, MAE, and R2 indexes. Although its prediction efficiency is slightly lower than that of the FOA-GRNN model, its prediction accuracy is significantly better than that of the other models. This proposed method can be used for temperature prediction in LDED process and also provide a reference for similar methods. -
2025, 54(9):2416-2428. DOI: 10.12442/j.issn.1002-185X.20240619Abstract:
Improving the hot working performance of difficult-to-deform alloys, such as powder metallurgy superalloys, is an important way to improve their formability, yield rate and the development of high performance alloys. Hot extrusion can effectively improve the microstructure of the alloy and enhance its hot working properties during the preparation process. This paper reviews the research progress on hot extrusion process parameters of powder metallurgy superalloys in recent years, systematically discusses the influence of hot extrusion parameters on the extrusion process and microstructure, and summarizes the research work on the selection and optimization of hot extrusion parameters. At present, the influence of extrusion speed and extrusion ratio on alloy microstructure, numerical simulation of hot extrusion process and optimization of extrusion device need to be further studied. This paper is used to provide reference for understanding the hot extrusion process and subsequent engineering practice, and to provide certain theoretical guidance and technical support for regulating the alloy microstructure, optimizing the hot working process and improving the hot working performance.2025, 54(9):2403-2415. DOI: 10.12442/j.issn.1002-185X.20240221Abstract:
Thermal barrier coatings (TBCs) can effectively reduce the actual operating temperature of hot-end components of advanced turbines and engines and improve their service reliability and durability. Yttria-stabilized zirconia (YSZ) TBCs are currently the most mainstream thermal barrier coating system, but as the thrust-to-weight ratio continues to increase, higher requirements have been placed on the performance of YSZ TBCs. As an important surface strengthening technique, laser remelting has been proven by many researchers to be used to strengthen YSZ TBCs and improve their overall performance. In this paper, the effects of laser remelting on the microstructure and properties of thermal sprayed YSZ TBCs and the strengthening mechanism are reviewed, including their microstructure, phase composition, thermal shock resistance, high- temperature oxidation resistance, calcium-magnesium-aluminum-silicon (CMAS) corrosion resistance and foreign-particle erosion resistance. Finally, the future development of this technique is discussed, which provides valuable reference for the research and application of thermal sprayed YSZ TBCs by laser remelting.2025, 54(9):2395-2402. DOI: 10.12442/j.issn.1002-185X.20240226Abstract:
Because of the special dimension effect and interface effect, film materials have unique advantages compared with bulk materials. Fe(Se,Te), an iron-sulfur superconductor, is more conducive to the study on superconducting mechanism because of its simple crystal structure. It has been found that single-layer FeSe superconducting films grown on SrTiO3 (STO) substrate significantly increase the superconducting transition temperature (Tc), which makes the study on FeSe superconducting films a new direction to understand the mechanism of unconventional superconductors. In addition, it is also found that the critical transition temperature of FeSe multilayer films is higher than that of bulk materials. The recent research achievements on the preparation of Fe(Se,Te) superconducting films and the enhancement of Tc by stress effect and interface effect were reviewed.2025, 54(9):2301-2312. DOI: 10.12442/j.issn.1002-185X.20240202Abstract:
The effect of material elastic modulus on stress and strain distribution in implants and bone tissue was investigated. Utilizing dental manufacturer and clinical statistical data, implant and mandible bone models were established. Material parameters for prepared Zr30Ti and Zr22Nb alloys were obtained through tensile testing, with Ti6Al4V (elastic modulus: 110 GPa) and Zr24Nb (elastic modulus: 30 GPa) selected as contrasting materials. Bone tissue was modeled using orthotropic material properties closer to real characteristics. Vertical and oblique loads were applied according to ISO 14801 standards, with a tilt angle of 30°. All studies were referenced against Ti6Al4V. Results show that the decrease in implant elastic modulus detrimentally affects its load-bearing capacity under oblique loads, with stress increments for Zr30Ti (76 GPa), Zr22Nb (59 GPa), and Zr24Nb (30 GPa) of 2.98%, 5.47%, and 14.55%, respectively. However, maximum stresses still remain below their strengths (952, 611, and 800 MPa). The stress transmission from implants is primarily borne by cortical bone, with maximum stress increments in cortical bone under oblique loads for Zr30Ti, Zr22Nb, and Zr24Nb of 17.59%, 31.92%, and 79.14%, respectively. The risk of cortical bone overloading increases with decrease in implant elastic modulus, but the stresses generated by Zr30Ti and Zr22Nb within cortical bone remain below cortical bone strength, ensuring favorable application safety. The stress transmitted from implants to cortical bone increases and becomes more uniform with decrease in elastic modulus, with average Mises stress increments at the implant-bone interface for Zr30Ti, Zr22Nb, and Zr24Nb under oblique loads of 12.75%, 122.94%, and 155.11%, respectively; while the stress difference at the interface for implant-bone decreases by 16.82%, 29.45% and 65.41%, respectively. This is attributed to larger deformation zones within implants with lower elastic modulus, where under oblique loads, the internal maximum strains in the neck region of Zr30Ti, Zr22Nb, and Zr24Nb implants are 2 times, 2.6 times, and 4.9 times greater than that of Ti6Al4V, respectively, with minimal differences in modulus between implants and bone tissue, promoting more coordinated deformation at the interface. Thereby, this can promote stress transfer to cortical bone and reduce interfacial stress difference. With decrease in elastic modulus, the stress at the bottom of cancellous bone implant sites gradually decreases, and the overall stress is concentrated in the upper part. The stress distribution of the cancellous bone in Zr30Ti and Zr22Nb zirconium alloy implants is more uniform.2025, 54(9):2273-2280. DOI: 10.12442/j.issn.1002-185X.20240184Abstract:
To investigate the complex interaction mechanism between elements Re and Ru, a dataset containing composition, microstructural parameters, kinetic parameters, physical parameters and macroscopic properties with the aid of high-throughput calculations were established, which effectively reduces the experimental cost and time. Results show that the addition of Re and Ru improves the creep life of the alloys by lowering the effective diffusion coefficient and stacking dislocation energy. The addition of the element Ru reduces the stacking dislocation energy and the antiphase domain energy, which in combination with the solid solution strengthening of Ru together affect the yield strength of the alloys, resulting in no significant change in the yield strength. At the same time, the four alloy systems were studied, element Re significantly promotes the tcp phase precipitation, while element Ru does not inhibit or promote the tcp phase precipitation. The element distribution behavior and the phase stability structure diagram of nickel-based superalloy was analyzed whether Ru inhibited or promoted the tcp phase precipitation. -
2025, 54(8):2164-2176. DOI: 10.12442/j.issn.1002-185X.20240150Abstract:
As an important type of Al alloys with excellent comprehensive properties, Al- Mg alloys with good corrosion resistance and weldability are widely used in aerospace, rail transit and marine ships. The recent research progress on the microstructure and property regulation of Al- Mg alloys during solidification, heat treatment and plastic deformation is summarized, and the characteristic of each regulation method is analyzed. The application of continuous rheo-extrusion forming technique in the fabrication of Al- Mg alloys is emphatically introduced, and the future development direction of Al- Mg alloys is prospected.2025, 54(8):2151-2163. DOI: 10.12442/j.issn.1002-185X.20240133Abstract:
Ni-based single crystal superalloys have excellent comprehensive properties at high temperature, and are widely used in hot-end components such as blades of aero-engines and gas turbines. Fatigue failure is one of the main failure modes of blades in service. Based on the research status of fatigue behavior of Ni-based single crystal superalloys, the fatigue damage mechanism of Ni-based single crystal superalloys was reviewed. The effects of crystal orientation, temperature and loading mode on fatigue behavior were discussed. The methods to optimize the fatigue life of Ni-based single crystal superalloys, such as composition optimization, heat treatment and surface treatment, were introduced. Finally, the application of some advanced testing techniques, such as in-situ testing, in the study of fatigue behavior of Ni-based single crystal superalloys was proposed, and the development trend of fatigue behavior research of Ni-based single crystal superalloys was prospected.2025, 54(8):2118-2124. DOI: 10.12442/j.issn.1002-185X.20240148Abstract:
The problem of ice accumulation on solid surface has a significant impact on both industrial sectors and human life, so exploring novel anti-icing materials is of great importance. In this study, polydimethylsiloxane with low surface energy was employed onto aluminum plates as a binder. Fe3O4 and Fe3O4/SiO2 dispersion liquids were separately sprayed to form hydrophobic coatings with photothermal effect. Fe3O4 provides photothermal effect and forms a certain micro-nano rough structure on the coating surface. When SiO2 is added, the hydrophobicity is further enhanced, with a water contact angle reaching 155°. This coating greatly delays the icing time and accelerates frost melting. Under one-sun illumination, the temperature rise can reach 71.8 ℃. The coating exhibits self-cleaning capability, effectively preventing severe contamination. It also demonstrates certain resistance to windblown sand impact and excellent mechanical stability, thereby providing a new direction for the development of anti-icing materials.2025, 54(8):1988-1996. DOI: 10.12442/j.issn.1002-185X.20240563Abstract:
To verify the wear resistance and erosion resistance of Ti-doped Ta2O5 coating (TTO), a series of TTOs were prepared by magnetron sputtering technology by controlling the power of the Ti target. The change of growth structure, microstructure, and tribological properties of TTOs with Ti target power was studied. After the erosion test, the variation of erosion damage behavior of TTOs with mechanical properties under different erosion conditions was further studied. The results show that the TTOs eliminate the roughness, voids, and defects in the material due to the mobility of the adsorbed atoms during the growth process, and a flat and dense smooth surface is obtained. Tribological tests show that the TTOs are mainly characterized by plastic deformation and microcrack wear mechanism. Higher Ti target power can improve the wear resistance of TTOs. Erosion test results reveal that the impact crater, furrow, micro-cutting, brittle spalling, and crack formation are the main wear mechanisms of the TTOs samples under erosion conditions.2025, 54(8):1980-1987. DOI: 10.12442/j.issn.1002-185X.20240411Abstract:
The high-entropy alloy composite coatings AlCu2Ti(NiCr)2-(WC)x (x denotes powder feeding speeds, including 0, 25, 50, and 75 r/min) were prepared by plasma cladding using a hybrid mode of AlCu2(NiCr)2Ti cable-type welding wire (CWW) and tungsten carbide (WC) powder. The effect of WC powder feeding speed on the microstructure, hardness, and wear properties of the prepared coatings was investigated. The results show that the coatings consist of body-centered cubic main phases and face-centered cubic secondary phases, with carbide reinforcement phases formed due to the addition of WC. The hardness and wear resistance of the coatings are significantly improved compared to the TC11 substrate. When WC powder feeding speed is set at 50 r/min, the coating exhibits optimal wear resistance, with a minimum volume wear rate of 8.5869×10-6 mm3·N-1·m-1, greatly improving the wear properties of TC11 surface. The coincident CWW-powder plasma cladding provides a viable method for the preparation of high-entropy alloy composite coatings with enhanced wear resistance.2025, 54(8):1926-1933. DOI: 10.12442/j.issn.1002-185X.20240421Abstract:
ZGH401 alloy was prepared under varying laser power levels and scanning speeds by the orthogonal test method using selective laser melting (SLM). The effect of different energy densities on microstructure and mechanical properties of the formed alloy was investigated. The microstructure of ZGH401 was analyzed by scanning electron microscope, electron back-scattered diffraction, and electron probe microanalysis. The results show that the defects of the as-built ZGH401 are gradually reduced, the relative density is correspondingly enhanced with increasing the energy density, and the ultimate density can reach 99.6%. An increase in laser power leads to a corresponding rise in hardness of ZGH401, while a faster scanning speed reduces the residual stress in as-built ZGH401 samples. In addition, better tensile properties are achieved at room temperature due to more grain boundaries perpendicular to the build direction than parallel to the build direction. The precipitated phases are identified as carbides and Laves phases via chemical composition analysis, with fewer carbides observed at the molten pool boundaries than within the molten pools. -
2025, 54(7):1895-1905. DOI: 10.12442/j.issn.1002-185X.20240633Abstract:
High efficiency solid-state neutron moderator materials are crucial component in micro-nuclear reactor. The main function of neutron moderator is to reduce the energy of neutrons produced by fission to a range that sustains further fission. Meanwhile, moderator materials are also one of the core structural materials in reactors. The application of high-temperature-resistant and efficient neutron moderator can help promote the development of miniaturization and mobility of micro nuclear reactors. Starting from the principle of moderators, several promising high-temperature resistant and efficient neutron moderators were summarized. The development prospects for different moderators were discussed, providing valuable guidance for subsequent researches and applications.2025, 54(7):1882-1894. DOI: 10.12442/j.issn.1002-185X.20240695Abstract:
With the rapid development of artificial intelligence (AI), its application in the field of nuclear fuel and materials is gradually becoming a new driving force for the advancement of nuclear energy technology. This article comprehensively reviews the current state of AI research in the field of nuclear fuel and materials and conducts an in-depth analysis of future development trends. It first introduces AI methods applied to scientific research, discussing from two aspects: network architecture and learning paradigms. Next it systematically summarizes the current state of AI applications in performance prediction at the material and structure levels of nuclear fuel materials, design optimization of materials and structures, and computer vision in fuel production and operation. The review then looks forward to the future development trends of the combination of AI with nuclear fuel and materials. At the algorithm level, it discusses methods to enhance the interpretability of machine learning models, quantify uncertainty, and the importance of limited supervised learning technology in reducing data requirements. At the application level, it discusses key technologies such as acceleration of multi-scale multi-physics field simulations, topological optimization and generative design, universal pre-trained models for nuclear material properties, and automated laboratories. Finally, several suggestions are proposed to further promote the application of AI in the field of nuclear fuel and materials.2025, 54(7):1838-1846. DOI: 10.12442/j.issn.1002-185X.20240108Abstract:
To improve the hardness and wear resistance of titanium (Ti), it is proposed to introduce TiB2 hard phase into pure Ti to accurately control the reaction process of the two components based on the discharge plasma sintering (SPS) technique, and to construct a TiB2-TiB-Ti "hard-core-strong-interface" structure in Ti matrix that inherits the diffusion path of B element. Finally, a high hardness of 863.5 HV5 at room temperature and 720.9 HV5 at 400 ℃ is obtained with the addition of 40% TiB2, which makes its friction performance better than that of commercial TC4 high-temperature titanium alloys under the same friction conditions in the temperature range from room temperature to 400 ℃. At the same time, thanks to its excellent bonding interface, the alloy also exhibits unique high-temperature and high-toughness properties, maintaining a high compressive strength of 1120 MPa and strain of about 11.7% at 400 ℃. The design idea of this study is inspiring and universal, which is expected to provide a new method for the research and development of new medium-high-temperature and high-toughness wear-resistant titanium alloys, and to promote the application of related materials in aerospace field.2025, 54(7):1741-1754. DOI: 10.12442/j.issn.1002-185X.20240771Abstract:
Zirconium alloys used as nuclear fuel cladding materials are subjected to neutron irradiation inside the reactor, which affects their corrosion resistance. Ion irradiation can be used to simulate neutron irradiation to study the effect of irradiation on corrosion behavior. In this study, the Zr-4 plate was irradiated with Ar+ at 360 ℃ with an electrostatic accelerator. The unirradiated and 5 dpa irradiated samples were corroded in 360 ℃/18.6 MPa/3.5 μL/L Li+1000 μL/L B aqueous solution and 400 ℃/10.3 MPa super-heated steam for 300 d. The microstructure of the samples was characterized by SEM and TEM. Results show that the Zr(Fe,Cr)2 second-phase particles in the unirradiated samples have hexagonal close-packed structures, whose Fe/Cr atomic ratio is in the range of 1.8–2.0, and the second-phase particles are amorphized after irradiation. Under the two corrosion conditions, during the corrosion process of the irradiated damage zone in the alloy matrix, the oxide film thickness of the irradiated samples is smaller than that of the unirradiated samples, indicating that Ar+ irradiation can enhance the corrosion resistance of Zr-4 to a certain extent. However, once the irradiated damage zone is fully oxidized, as corrosion proceeds, the oxide film thickness of the irradiated samples becomes greater than that of the unirradiated samples, suggesting that the oxide film formed in the irradiated damage zone facilitates the diffusion of oxidative ions, accelerating the corrosion of Zr-4. The influence of irradiation on the corrosion resistance of Zr-4 at different stages is discussed from the perspectives of microstructure evolution and stress accumulation in the oxide film induced by irradiation-induced defects. -
2025, 54(6):1641-1652. DOI: 10.12442/j.issn.1002-185X.20240046Abstract:
Shape memory alloys (SMA) possess both the shape memory effect and superelasticity. This material plays a significant role in the aviation field, and it is crucial to understand its types, mechanisms, preparation, and processing techniques. This review focused on the research progress of SMA in aviation applications. Considering the material characteristics of SMA, its application research in aviation fields was analyzed, such as pipe joints, deformable wings, air intake fairings, and intelligent noise reduction nozzles. The research findings indicate that as aviation manufacturing technology advances, the application of SMA is expected to evolve towards high temperature resistance, lightweightness, and intelligence.2025, 54(6):1581-1587. DOI: 10.12442/j.issn.1002-185X.20240055Abstract:
The stress of human bone in daily activities is complex. To obtain the optimal porous titanium alloy structure suitable for bone implants, it is necessary to analyze the mechanical properties of porous structures. According to the compression, torsion, and bending loads of human bone, three kinds of porous structures (TO-C, TO-T, and TO-B) were designed and reconstructed by topology optimization method. The mechanical properties of different porous structures were studied by finite element simulation in compression, torsion and bending states. Finally, the compression test of porous specimens prepared by selective laser melting technique was carried out. The simulation results show that the compressive strength and bending strength of TO-B structure are optimal, while the torsional strength of TO-T structure is optimal. The compression test shows that the compressive strength of three structures at a porosity of 60% ranges from 188.35 MPa to 258.88 MPa and the elastic modulus ranges from 2.51 GPa to 4.16 GPa, all of which meet the requirements of human bones. By combining simulation and compression test to comprehensively analyze the mechanical properties of porous structures, it is found that TO-B structure has the best comprehensive performance and is the optimal type of porous structure for orthopedic implants.2025, 54(6):1535-1542. DOI: 10.12442/j.issn.1002-185X.20240081Abstract:
Functionally gradient cathodes (FGC) realize the combination of ablation-resistant surface and conductive matrix, which can effectively extend the cathodic service life. Nb/Cu FGC, with Nb layer and Cu as surface and matrix, respectively, was prepared by laser cladding. The microstructure, composition, and the phase information were characterized. The microhardness and thermal conductivity of the FGC were tested. Furthermore, the cathodic discharge and ablation behavior in Ar atmosphere were investigated. Results show that several scattered cathode spots appear and densely distributed ablation craters are observed. The Nb/Cu FGC displays relatively moderate ablation behaviors. The average ablation rate of Nb/Cu FGC (1.61 μg/C) is 26.1% lower than that of Cu cathodes (2.18 μg/C), as ascribed to the synergy of ablation resistant Nb surface and the highly-conductive Cu matrix. Nb/Cu FGC exhibits the potential in arc plasma applications.2025, 54(6):1417-1425. DOI: 10.12442/j.issn.1002-185X.20240247Abstract:
Through a modified inherent strain model based on the minimum residual stress and deformation, three building schemes with different building postures and support structures were evaluated by finite element analysis. Results demonstrate that according to the principle of reducing the overall height of the building and reducing the support structure with a large tilt angle from the building direction, the residual stress and deformation can be effectively reduced by proper design of building posture and support before laser powder bed melting. Moreover, without the data of thermophysical property variation of Ti-6Al-4V artificial knee implants with temperature, predicting the residual stress and deformation with acceptable accuracy and reduced time cost can be achieved by the inherent strain model. -
2025, 54(5):1377-1396. DOI: 10.12442/j.issn.1002-185X.20250029Abstract:
Magnesium alloys hold tremendous potential for applications in automotive lightweighting, with reliable joining being one of the key technical issues for lightweight manufacturing. Laser welding is a suitable joining technology for the development of magnesium alloys due to its low heat input. However, the insufficient in-service performance for laser-welded joints of magnesium alloys, currently restricts their engineering applications. This paper summarizes the cutting-edge research progress in laser welding of magnesium alloys, with a focus concentrated on the intrinsic characteristics of laser welding of magnesium alloys and the influence of welding process parameters on the quality of welded joints. Meanwhile, taking into consideration the critical issues found in the cases of magnesium alloys for automotive utilization, the core influencing factors, regarding the service performance of laser-welded joints of magnesium alloys for automotive applications, are reviewed, and the prospect for future development is proposed.2025, 54(5):1344-1352. DOI: 10.12442/j.issn.1002-185X.20240041Abstract:
REBa2Cu3O7-x(YBCO) high-temperature superconducting coated conductors (CCs), i.e. the second-generation high-temperature superconducting tapes, with excellent current carrying properties and mechanical behavior, are potentially applied in the fields of power, transportation, medical care, and military, receiving extensive attention from superconductor research teams in recent years. Increasing the thickness of the superconducting layer in CCs is facilitated to enhance the superconducting current transmission capability and to increase the engineering critical current density, thus being one of the major routes to reduce the cost of CCs. The "thickness effect", i.e. the critical current density (Jc) decreases with the increase in film thickness, mainly hinders the fabrication of high-quality superconducting thick films. This study introduced the preparation methods and epitaxial growth mechanism of YBCO thick films, discussed various factors that affect Jc and main ways to improve Jc, and summarized the latest research progress of YBCO thick films from major international teams.2025, 54(5):1134-1144. DOI: 10.12442/j.issn.1002-185X.20240228Abstract:
Thermal deformation characteristics of Fe-Cr-Ni-based alloys for nuclear power plants were investigated using a Gleeble-3500 thermal simulation tester. The microstructure evolution law of alloy heat deformation was investigated using the electron backscatter diffraction (EBSD) technique. Results demonstrate that the flow stress curves show typical dynamic recrystallization (DRX) characteristics. According to EBSD analysis, the nucleation and growth of DRX grains are mainly at grain boundaries. The complete DRX occurs at 1100 °C/0.01 s-1 condition, and the grains are refined. The main DRX nucleation mechanism of the alloy is the grain boundary bowing nucleation. Therefore, the softening mechanism of Fe-Cr-Ni-based alloys for nuclear power plants is the combination of dynamic recovery and DRX. The Arrhenius constitutive model with strain compensation is developed. The correlation coefficient between the predicted and experimental values is 0.9947. The reliable mathematical model of critical stress (strain) and Z parameter is obtained. The critical stress (strain) of DRX increases as the temperature decreases or the strain rate increases. The DRX kinetic model is established by the Avrami model, and a typical S-type curve is obtained. As the strain rate decreases and the temperature increases, the volume fraction of DRX increases.2025, 54(5):1127-1133. DOI: 10.12442/j.issn.1002-185X.20240720Abstract:
TaN coatings were deposited on Ti bipolar plates by magnetron sputtering to improve corrosion resistance and service life. The influence of N2 flow rate on the surface morphology, hydrophobicity, crystallinity, corrosion resistance, and interfacial contact resistance of TaN coatings was studied. Results show that as the N2 flow rate increases, the roughness of TaN coatings decreases firstly and then increases, and the hydrophobicity increases firstly and then decreases. At the N2 flow rate of 3 mL/min, TaN coating with larger grain size presents lower roughness and high hydrophobicity. The coating possesses the lowest corrosion current density of 2.82 μA·cm-2 and the highest corrosion potential of -0.184 V vs. SCE in the simulated proton exchange membrane water electrolyser environment. After a potentiostatic polarization test for 10 h, a few corrosion pits are observed on the TaN coatings deposited at an N2 flow rate of 3 mL/min. After 75 h of electrolytic water performance testing, the TaN coating on bipolar plate improves the corrosion resistance and thus enhances the electrolysis efficiency (68.87%), greatly reducing the cost of bipolar plates.2025, 54(5):1121-1126. DOI: 10.12442/j.issn.1002-185X.20240561Abstract:
The effect of deformation resistance of AlCr1.3TiNi2 eutectic high-entropy alloys under various current densities and strain rates was investigated during electrically-assisted compression. Results show that at current density of 60 A/mm2 and strain rate of 0.1 s-1, the ultimate tensile stress shows a significant decrease from approximately 3000 MPa to 1900 MPa with reduction ratio of about 36.7%. However, as current density increases, elongation decreases due to intermediate temperature embrittlement. This is because the current induces Joule effect, which then leads to stress concentration and more defect formation. Moreover, the flow stress is decreased with the increase in strain rate at constant current density. -
2025, 54(4):1087-1095. DOI: 10.12442/j.issn.1002-185X.20230764Abstract:
Zirconium alloy coating can improve the accident resistance of zirconium alloy cladding without changing the present fuel system, which is one of the hot research directions to improve the accident-tolerant ability of nuclear fuel assemblies. Cr-based coating is the most widely concerned coating material at the current stage. The development progress and design ideas from Cr coatings to various Cr-based coatings after Fukushima nuclear accident were systematically reviewed in this paper. The selection basis and high-temperature oxidation failure mechanism of Cr-based coating were introduced. The solution ideas and research progress were discussed from two aspects of composition design and structure design. Finally, the development prospect of Cr-based coating on zirconium alloy in the future was proposed. The review has important reference significance for the development and application of the new generation of accident tolerant fuel coating technique in the future.2025, 54(4):1072-1086. DOI: 10.12442/j.issn.1002-185X.20230767Abstract:
Hot isostatic pressing combined with mold control technique can achieve near-net shaping of complex high-performance components. The mold core is crucial for controlling the internal structural accuracy of the formed parts. Presently, mold cores predominantly employ metallic materials. However, these metallic cores are susceptible to substantial deformation under elevated temperatures and pressures. The removal of acid-induced corrosion is not only inefficient but also environmentally unsound. The diffusion of foreign elements from the metal mold cores results in contamination of parts. Additionally, issues such as embedding of forming powder into the surface lead to poor surface quality of the parts. These problems hinder the development of hot isostatic pressing to the forming of complex internal cavity parts. Ceramic mold cores exhibit low chemical reactivity and minimal interdiffusion with metal elements. Its high temperature hardness and stiffness confer resistance to deformation, and its core removal rate is high under alkaline conditions. The above advantages offer a potential solution to issues caused by metal cores. Based on representative literature and research advancements in the field of ceramic mold cores for casting, this paper focuses on analyzing the synergistic relationship between the mechanical and dissolution properties of ceramic mold cores used in hot isostatic pressing. This paper provides a detailed introduction and comparison of the optimization strategies for mechanical properties, dissolution performance, and moisture resistance of silicon oxide, aluminum oxide, calcium oxide, and magnesium oxide-based ceramics used in hot isostatic pressing cores. This paper also explores complex high-precision structural formation, sintering, and post-processing methods. Additionally, it anticipates challenges and future directions for the application of ceramic cores in the near-net shaping hot isostatic pressing process.2025, 54(4):1053-1071. DOI: 10.12442/j.issn.1002-185X.20230787Abstract:
Directionally solidified superalloys are widely used in turbine blades of advanced power propulsion systems such as industrial gas turbines due to their excellent high-temperature strength, creep resistance, corrosion and oxidation resistance, as well as good structural stability and casting properties. Directionally solidified superalloys for gas turbines have been developed from the first generation to the fourth generation by adjusting the proportions of different solid solution strengthening, precipitation strengthening and grain boundary strengthening elements. The intragranular structures are mainly composed of γ phase and γ? phase. There are carbides, borides and other precipitates at the grain boundaries that can pin the grain boundaries. Under the joint influence of these strengthening phases, nickel-based directionally solidified superalloys have better tensile and creep properties that can change with temperature. Starting with the composition characteristics and microstructure characteristics, this article combines the current application status of directionally solidified superalloys in gas turbines, and further analyzes its performance characteristics. Finally, it looks forward to future research on directionally solidified superalloys.2025, 54(4):983-992. DOI: 10.12442/j.issn.1002-185X.20230774Abstract:
In this work, medium and high entropy alloy coating was prepared on the surface of 38CrMoAl by laser cladding technique. The effects of adding elements such as Al, Si, Fe, and Nb to CoCrNi series alloys on the phase, microstructure, and element distribution of the alloy coating were studied. The hardness, wear resistance, and electrochemical properties of the coating were analyzed and characterized. The results indicate that CoCrNi alloy has a face-centered cubic (fcc) crystal structure, and the addition of Al and Fe promotes the formation of body-centered cubic (bcc) phase. After the addition of Nb and Si elements, a Laves/bcc eutectic+Nb-riched composite phase is formed in the septenary-element-alloy coating, and the microstructure is significantly refined. The comprehensive performance of CoCrNi-based medium and high entropy alloy coatings is superior to that of 38CrMoAl substrate. Compared with CoCrNi and AlCoCrFeNi alloy coatings, the hardness, wear resistance, and corrosion resistance of AlSiCoCrFeNiNb coatings have been significantly improved: the surface hardness is 713.3 HV0.1, which is 3.24 times higher than that of the substrate. The wear mechanism is mainly slight abrasive wear and adhesive wear, with an average coefficient of friction of 0.52 and a wear rate of 115.73×10–12 mm3/(N·m), reduced by 64.4% compared with that of the substrate. The self corrosion potential (Ecorr) is –0.3392 V, and self corrosion current density (Icorr) is 0.472 μA·cm-2.2025, 54(4):862-870. DOI: 10.12442/j.issn.1002-185X.20240122Abstract:
A static corrosion experiment of 347H stainless steel alloyed with elements Cu and Mo was carried out in a nitrate molten salt (60% NaNO3+40% KNO3) at 565 °C for 720 h. The effects of elements Cu and Mo on the corrosion resistance of 347H stainless steel in molten salt were investigated by analyzing the phase composition, microstructure and chemical composition of the corrosion products. The results show that the grain refinement induced by element Mo imparts the stainless steel with optimal corrosion resistance at a medium grain size. Furthermore, the formation of MoC significantly enhances the intergranular corrosion resistance of the stainless steel. The stainless steel exhibits uniform corrosion in the nitrate solution. The corrosion layer displays a dual-layer structure, and the corrosion products protecting matrix are present in both the inner and outer layers. The outer layer consists of a mixture of Fe oxides (Fe2O3, Fe3O4), NaFeO2, and a minor amount of MgFe2O4. Conversely, the inner layer is primarily composed of a spinel layer (FeCr2O4, MgCr2O4) and a thin Cu2O layer. The oxidation of Cu in the inner layer leads to the formation of a dense Cu2O layer, effectively impeding O2- plasma infiltration into the matrix. -
2025, 54(3):818-836. DOI: 10.12442/j.issn.1002-185X.20240629Abstract:
The basic properties, structural, and functional applications of copper were described and the process characteristics and joint properties of copper brazing were and analyzed. The current research status of brazing between copper and dissimilar materials such as steel, aluminum, titanium, ceramics, and carbon-based materials were reviewed and examples of studies on brazing copper with heterogeneous structures were listed. Specific considerations in the brazing process were also examined, including brazing filler metal selection, process formulation, interlayer design, use of brazing equipment, and performance inspection. The importance of joining structure and joint interface design was emphasized. Furthermore, it is proposed that the development direction of copper brazing should focus on being green, intelligent, reliable, and low-cost, providing a technical reference for the engineering applications of copper and the brazing fabrication of heterogeneous structures containing copper.2025, 54(3):791-802. DOI: 10.12442/j.issn.1002-185X.20240533Abstract:
Steel material is the main structural material of marine equipment, but its corrosion usually occurs in the marine atmosphere environment, thus affecting its service performance. Compared with general atmospheric corrosion, marine atmospheric corrosion is affected by sea salt aerosols, chloride ions and other specific factors of marine atmosphere. In addition, the marine atmospheric corrosion properties of steel materials are closely related to the alloying elements of the materials. This paper reviewed the relevant studies of worldwide scholars on the effect of rare metal doping on the marine atmospheric corrosion resistance of steel materials in recent years, and summarized the corrosion mechanism of carbon steel, stainless steel, weathering steel and other common structural steels under marine atmospheric environment. The effects of Nb, Mo, Sb, Sn, Ce, La, Y and other rare metal elements on the marine atmospheric corrosion resistance of steel materials were analyzed. For weathering steel and carbon steel, the effect of rare metal elements on the structure of rust layer was mainly discussed. For stainless steel, the effect mechanism of rare metal elements on inclusion modification and pitting behavior of stainless steel was discussed. The future research directions were prospected, in order to provide references for the application of rare metal doped steel in marine atmospheric environment and for the improvement of marine atmospheric corrosion resistance.2025, 54(3):755-764. DOI: 10.12442/j.issn.1002-185X.20230730Abstract:
AZ91-La-Yb magnesium alloy as anode of seawater batteries was prepared by combining mechanical alloying with spark plasma sintering processes. The effects of rare earth La-Yb doping on the microstructure and electrochemical behavior of AZ91 anode were studied. The results show that the AZ91-La-Yb alloy prepared by mechanical alloying-spark plasma sintering processes consists of equiaxed grains. On the one hand, La-Yb doping results in the formation of micron-scale (0.5–2 μm) RE-rich phase that are uniformly distributed at grain boundaries. This phase is mainly composed of rare earth metals (RE=La, Yb) and Mg(RE) solid solution. On the other hand, the plastic deformation caused by discharge plasma sintering and the doping effect of rare earth elements La-Yb significantly improve the morphology of β-Mg17Al12 phase, transforming from a coarse network structure to a slender elongated shape. The combination of uniform distribution of nearly micron-scale RE-rich phase and the smaller β phase promotes the uniform dissolution of magnesium alloys and effectively alleviates localized corrosion of magnesium alloys. Compared to the AZ91 anode magnesium alloy, the AZ91-La-Yb alloy doped with rare earth La-Yb exhibits more stable discharge voltage and excellent discharge performance. At a current density of 20 mA/cm2, its specific capacity can reach 1068 mAh/g, and the anode utilization efficiency is 50.4%.