镍丝与多股铜线电阻钎焊接头形成机理及微观组织

Formation mechanism and microstructure of resistance brazing joint of nickel wire and multi-strand copper wire

为实现航空传感元器件引线与多股铜导线优质连接,提升其可靠性及产品安全性。文中采用石墨精密电阻钎焊设备,实现多股铜导线/镍丝良好钎焊连接。通过扫描电镜分析焊接接头横截面微观组织,总结阐述多股铜导线/镍丝钎焊接头形成机理。结果表明:石墨电阻热使铜丝溶解于钎料中形成岛状富Cu相,均匀分布于钎焊区域;受温度梯度及元素浓度梯度影响,铜丝/镍丝表面富Cu相沿径向生长。

In order to achieve high-quality connection between the aeronautical sensing component leads and the multi-strand copper wire,the reliability and product safety were improved.In this paper,graphite precision resistance brazing equipment was used to achieve good brazing connection of multiple strands of copper wire to nickel wire.The microstructure of the welded joint cross section was analyzed by scanning electron microscopy.The formation mechanism of the multi-strand Cu/Ni wire brazed joint was summarized.The results showed that the graphite resistance heat dissolved Cu in the melted brazing filler metal to form an island-like Cu-rich phase,which was evenly distributed in the brazing region.Due to the temperature gradient and element concentration gradient,the growth direction of Cu-rich phase was along the diameter of the copper or nickel wire.