TiNi形状记忆合金与不锈钢瞬间液相扩散焊工艺研究

Research on Transient Liquid Phase Diffusion Bonding Process of TiNi Shape Memory Alloy to Stainless Steel

采用AgCu中间过渡层,研究了连接温度、保温时间和连接压力对TiNi形状记忆合金与不锈钢瞬间液相扩散焊接头剪切强度的影响规律。本实验条件下连接温度为860℃,保温时间为60min,连接压力为0.05MPa时接头剪切强度最大为239.4MPa。通过扫描电镜(SEM)和X射线衍射仪(XRD)研究了最佳工艺参数下接头的元素分布和相组成,结果表明:接头生成了TiNi2,TiFe和Ti3Ni4等金属间化合物,从而影响接头性能。

Transient liquid phase diffusion bonding（TLP-DB） of TiNi shape memory alloy（SMA） to stainless steel was performed with AgCu foil as interlayer. The effect of bonding temperature, holding time and bonding pressure was also investigated. The results showed that the maximum shear strength of the joint was obtained for the specimens joined at 860℃ for 60 minutes with a specific pressure of 0.05MPa. Through scanning electron microscopy（SEM） and X-ray diffractometry（XRD） test, the element distribution and phase composition of the joint welded under the optimum process parameters were investigated. It indicated that the joint property was significantly influenced by the formation of intermetallics TiNi2, TiFe and Ti3 Ni4 etc.