镍元素对AgCu28钎焊焊缝的影响

Influence of Ni-Addition on Microstructures and Properties of Seam Brazed with AgCu28 Solder

在氢气气氛下,对TU1、4J33和镀镍4J33进行钎焊,使用钎料为AgCu28和AgCu28Ni0.75,利用扫描电镜、能谱分析仪和金相显微镜,对钎焊焊缝微观组织形貌进行观测。结果表明,在实验的钎焊工艺下,AgCu28钎料钎焊TU1的焊缝组织良好,为银铜共晶组织,基本无晶界渗透现象,AgCu28Ni0.75钎料钎焊TU1的焊缝,钎料向母材晶界渗透现象严重;在AgCu28钎料中添加镍元素,或被焊母材含有镍元素或者被焊接母材外有镀镍层时,钎焊焊缝出现明显的成分偏析现象。

Herein,we experimentally addressed the brazing in H2 atmosphere of microwave electric vacuum device components,made of TU1,4 J33 and Ni-plated 4 J33 alloys,with AgCu28 and AgCu28 Ni0.75 solders.The influence of the addition of Ni in AgCu28 solder on the microstructures,phases and mechanical behavior of the welded seam was investigated with scanning electron microscope,energy dispersive spectroscopy and metallographic microscope.The preliminary results show that the Ni addition had a major impact.To be specific,Ag-Cu eutectic alloy formed at the well-brazed TU1 seam with no grain boundary penetration;AgCu28 Ni0.75 solder was found to seriously diffuse into the grain boundaries of the base metal.In addition,the Ni,added into AgCu28 solder and/or plated on the base metal surfaces,accounted for the significant surface segregation.