连接温度对Zr/Ta扩散连接接头界面组织及性能的影响

Effect of Bonding Temperature on Interfacial Microstructure and Properties of Zr/Ta Diffusion Bonded Joints

摘要:

锆合金凭借优异的耐腐蚀性能和低的热中子吸收截面，在核工业领域受到了极大的关注及应用，特别是用于腐蚀环境的溶解器设备。本工作对Zr-3合金和难熔金属钽的扩散连接界面组织及力学性能进行了研究，探究了扩散连接温度对锆/钽接头剪切强度的影响，并对连接接头界面结构和断口进行分析，以及对连接接头的耐腐蚀性能做了初步研究。结果表明，接头典型界面结构为Zr/α-Zr+β-(Zr,Ta)固溶体/Ta，扩散层厚度随连接温度升高逐渐增厚。接头剪切强度随温度升高呈现先上升后下降的变化趋势，900 ℃-30 min-10 MPa的连接工艺下接头强度达到最大值，为385 MPa，断口呈现混合断裂特征。此外，锆/钽扩散连接接头展现出较好的耐腐蚀性能。

Abstract:

Zirconium alloys have garnered significant attention and widespread application in the nuclear industry due to their exceptional corrosion resistance and low thermal neutron absorption cross-section, particularly in dissolver equipment for highly corrosive environments. This study investigated the diffusion bonding interface microstructure between Zr-3 alloy and refractory metal tantalum as well as their mechanical properties. The effect of diffusion bonding temperature on the shear strength of zirconium/tantalum joints was examined. Additionally, the interface structure and fracture surface morphology of the joints were analyzed, and a preliminary study on the corrosion resistance of the joint was conducted. Results show that the typical interface structure of the joint is Zr/α-Zr+β-(Zr,Ta) solid solution/Ta, with the thickness of the diffusion layer increasing gradually as the bonding temperature rises. The shear strength of the joint initially increases and subsequently decreases with rising temperature. Under the bonding conditions of 900 °C-30 min-10 MPa, the joint strength reaches its maximum value of 385 MPa, with the fracture surface exhibiting mixed fracture characteristics. Furthermore, the zirconium/tantalum diffusion bonding joint demonstrates excellent corrosion resistance.