Au-Ag-Si系钎料合金与Ni的润湿性

Wettability of Au-Ag-Si brazing filler metal series with Ni

通过分析相图,采用中频感应真空熔炼制成液相点温度在450～500℃之间Au-10．22Ag-3．25Si, Au-14．02Ag-3．28Si和Au-18．47Ag-3．27Si 3种不同成分的Au-Ag-Si系钎料合金。分别在其液相点以上20,40和60℃及流动氢气保护下进行钎料在Ni板上的铺展试验,通过分析铺展面积及润湿角,研究其与Ni的润湿性;采用背散射电子相观察钎料与Ni润湿后的界面组织。研究结果表明:Au-Ag-Si系钎料合金与Ni润湿性良好,随着钎焊温度的增加,铺展面积增加,浸润角减小;钎料合金与Ni润湿后,出现润湿环现象;润湿环主要由Au元素组成;钎料与Ni润湿后,在界面处形成Ni3Si金属间化合物,Ni3Si的形成在一定程度上可提高钎料焊接强度。

Based on the phase diagram, three kinds of Au-Ag-Si brazing filler metal with three different constituents, i.e., Au- 10.22Ag-3.25Si, Au- 14.02Ag-3.28Si and Au- 18.47Ag-3.27Si were prepared by using the vacuum melting method in a medium-frequency induction furnace. The spreading-out experiment of the Au-Ag-Si brazing filler metal on Ni sheet was done at 20, 40 and 60 ℃ above its liquidus temperature respectively with flow H2 as protective gas. The wettability of the Au-Ag-Si brazing filler metal with Ni was studied by measuring and analyzing the area-of-spread and wetting angle. The interface structure of the brazing filler metal with Ni after its spreading was observed by backscattered electron images. The results show that the Au-Ag-Si brazing filler metal series have a good wettability with Ni. When brazing temperature increases, the area-of-spread increases and the wetting angle decreases, there are wetting rings when brazing filter metal is wetted with Ni. The wetting rings principlely consist of Au element. The intermetallic of Ni3Si is formed at the interface, and the formation of Ni3Si can improve the brazed joint strength to some degree.