Effects of surface microstructure on the active element content and wetting behavior of brazing filler metal during brazing Ti3SiC2 ceramic and Cu

Abstract

The wetting behavior of Ag-Cu-xTi (x = 0, 0.5, 1, 2, 3, 4.5 wt. %) brazing filler metals on Ti3SiC2 ceramic was investigated. Moreover, two methods, the addition of reactive element Ti in filler metals and surface microstructure on Ti3SiC2, were used to decrease the wetting angle of filler metals. When employing the addition of Ti, the wetting angle of Ag-Cu-xTi gradually decreased with increasing the content of Ti from 0 to 4.5 wt. %, while the interface brittle compounds increased during the same course. According to wetting theory, a square convex platform and groove microstructure was designed to promote the wetting of Ag-Cu-2Ti. The microstructure was processed on Ti3SiC2 surfaces by laser machine, the effects of microstructures on wetting behavior were verified experimentally.The results show that the wetting angle of Ag-Cu-2Ti on Ti3SiC2 with surface microstructure decreased effectively compared with that on smooth Ti3SiC2. Meanwhile, the same wetting behavior and less interface brittle compounds could be achieved by using surface microstructure and filler metal with less Ti. The experimental results had a sound fit with theoretical calculation. The novel method provided a feasible route for optimizing filler metal composition and promoting the application of filler metals with less reactive element in brazing field.