添加铜箔中间层的NiTi形状记忆合金超声波焊接

采用超声波焊接方法对添加铜箔中间层的NiTi形状记忆合金进行搭接焊，研究接头的表面形貌、界面形貌、相变行为、抗拉性能和断裂特点. 结果表明，超声波焊接能实现添加铜箔中间层的薄片状NiTi形状记忆合金的有效连接. NiTi焊缝表面存在明显压痕，界面处结合良好，无金属间化合物生成. NiTi形状记忆合金超声波焊缝呈可逆单相转变过程，接头强度达到母材的65%，断裂位置在母材区，断口形貌呈现韧性断裂特征. 超声波焊接方法将有效解决NiTi形状记忆合金采用传统熔焊方法时产生脆性金属间化合物的这一问题，为NiTi记忆合金的连接提供了新的解决途径.

Ultrasonic welding of NiTi shape memory alloy with Cu interlayer

Ultrasonic welding method was applied to NiTi shape memory alloy with Cu interlayer, and the surface morphology, interface morphology, phase transformation behavior, tensile properties and fracture characteristics of NiTi joint were studied. The results show that ultrasonic welding technique can effectively join NiTi shape memory alloy with Cu interlayer. There are obvious indentations on the surface of NiTi welding due to the effect of sonotrode tip. Well bonding could be observed at the weld interface, and no intermetallic compound was formed. Ultrasonic welding NiTi shape memory alloy showed a reversible phase transition process. The strength of NiTi memory alloy joints reached 65% of the base material, and the fracture surface showed ductile fracture characteristic. Ultrasonic welding method conlat solve the problem of brittle intermetallic compounds produced by traditional fusion welding method, which provides a new solution for the connection of NiTi shape memory alloys.