Au-19.25Ag-12.80Ge钎料的焊接性能研究

Welding Performance Study on Au-19.25Ag-12.80Ge Brazing Alloy

根据Au-Ag-Ge三元相图,制备了新型Au-19.25Ag-12.80Ge（%,质量分数）钎料合金。利用DTA,Sirion200场发射扫描电镜对钎料的熔化特性及显微组织进行分析,并对其与纯Ni的润湿性加以研究。结果表明：Au-19.25Ag-12.80Ge钎料合金的熔化温度为446.76-494.40℃,结晶温度区间为47.64℃;焊接温度在510-550℃范围内时,Au-19.25Ag-12.80Ge钎料合金与Ni基体具有良好的铺展性和润湿性,在熔化钎料前沿有润湿环现象出现,钎料合金与Ni基体之间形成了一条连续的金属间化合物层,能谱分析表明该金属间化合物层为Ge3Ni5金属间化合物,由于该化合物层较脆,故应控制焊接工艺以获得连续均匀且厚度适当的金属间化合物层;对于本钎料合金而言,焊接温度530℃,保温时间10min可获得较理想的焊接界面。

According to Au-Ag-Ge phase diagram, anew-type brazing alloy Au-19.25Ag-12.80Ge （%,mass fraction） was prepared. The melting characteristics and microstructure of the solder alloy were ana- lyzed using DTA and Sirion 200 field emission scanning electron microscope, and its wettability with pure Ni was also studied. The results showed that, the range of melting temperature of Au-19.25Ag-12.80Ge brazing alloy was 446.76 - 494.40 ℃, and the tem- perature interval between the solidus and the liquidus was 47.64 ℃. When the soldering temperature was in the range of 510 - 550 ℃, the brazing alloy had a good spreadability and wettability with Ni, and a wetting ring appeared in the front of the brazing alloy afterspreading. The observation of interface structure revealed that there was one continuous IMC layer between the brazing alloy and the base metal Ni. X-ray energy dispersive spectrum analysis results showed that the IMC layer was Ge3Ni5 intermetallics. Because of its brittleness, a continuous and uniform IMC layer with proper thickness could be gained by controlling the welding condition. For Au-19.25Ag-12.80Ge brazing alloy, an ideal welding interface could be obtained, when the welding temperature was 530 ℃ and the holding time was about 10 min.