钎焊过程原位合成高强度银钎料

AgCuZnSn合金具备高强度、成分无害化的优势,在绿色制造中应用前景广阔,但Sn元素的加入导致的成形性能下降,限制了其使用. 为克服该不足,设计了一种使用AgCuZn/ZnCuAgSn/AgCuZn复合焊片在钎焊过程中原位合成AgCuZnSn高强钎料的方法,采用的复合钎焊片外层为AgCuZn低熔合金,内层为ZnCuAgSn合金,二者熔点接近且内层合金低于合成后钎料熔点,复合钎料的加工性优于同成分的AgCuZnSn钎料. 使用复合钎焊片进行了感应钎焊不锈钢试验. 结果表明,钎焊过程中两种合金几乎同时熔化,经瞬间保温后可充分熔合,获得高强度钎缝,采用该工艺获得的接头强度高于常规钎焊连接强度.

In-situ synthesis of high strength Ag brazing filler metals during brazing process

The AgCuZnSn alloy is Cd-free and has high strength, makes it has a board application prospect in green manufacture, while the decrease in forming property induced which element limits its application. To overcome that weak point, a method to in-situ synthesis high strength Ag brazing alloy by using AgCuZn/ZnCuAgSn/AgCuZn composite sheet during the brazing process is proposed in the paper. The outer layer of the composite sheet is AgCuZn alloy, and the inner is ZnCuAgSn alloy. The melting points of the two alloys are close and melting point of the inner alloy is lower than the synthesized alloy, and the process ability of the composite sheet is better than the AgCuZnSn alloy with the same composition. Brazing of stainless steel using the composite brazing sheet was studied. It was found that the two alloys melt at the same time, and fused comprehensively after holding for a short time, forming high strength brazing seam. The strength of the obtained brazed joint is much higher than the joints brazed using common AgCuZn alloy.