PZT压电陶瓷与TC4合金钎焊连接界面结构设计

Piezoelectric ceramics are used in the manufacture of ultrasonic motor because of its inverse piezoelectric effect. However, some problems of poor joint conductivity, easy aging and low connection accuracy caused by organic bonding in the manufacture of ultrasonic motor need to be solved. In this paper, the surface of PZT piezoelectric ceramics was metallized via magnetron sputtering to improve the weldability between PZT piezoelectric ceramic and TC4 titanium alloy. The results show that the bonding force between Ag and base metal is poor, and the unwelded position appears at the junction of Ag layer and base metal. The welding is easy to occur at the junction of Ti and Ag when Ti/Ag is a metallized layer due to the poor bonding force between Ag and Ti. Ni and solder can form Ni-Sn layer to improve the joint reliability when the metallized layer is Ni/Ag. A composite metal layer, that is, the base metal/Ti/Ni/Ag structure, was selected as a metallized layer on the base metal surface, and the typical microstructure of the joint was analyzed. The results show that the composite metal layer can improve the bonding strength between the metallized layer and the base metal and realize the effective bonding between the BASE metal of PZT ceramics and TC4 alloy. The microstructure of the interface is β-Sn/Ag₃Sn/β-Sn+Ni₃Sn₄/Ni₃Sn+Ni/Ti₂Ni/Ti₂Ni+α-Ti/PZT.