退火时间对AgCuZnNiMn/Cu/AgCuZnNiMn多层复合钎料元素扩散行为的影响

Effect of annealing time on element diffusion behavior of AgCuZnNiMn/Cu/AgCuZnNiMn multilayer composite brazing filler metal

采用扫描电镜(SEM)、能谱仪(EDS)和万能力学试验机等研究了500℃退火不同时间对AgCuZnNiMn/Cu/AgCuZnNiMn多层复合钎料界面元素扩散行为与钎焊力学性能的影响。结果表明:复合钎料界面扩散层主要为银基固溶体、铜基固溶体;随退火时间的增加,物相发生明显粗化,界面两侧元素不断发生互扩散,当退火时间为24 h时,界面扩散层厚度达20μm。同时,随退火时间的增加,钎焊接头界面处的应力缓释Cu层逐渐减少直至消失,接头强度从224 MPa下降到165 MPa,接头断裂机制从以韧窝为主的韧性断裂向韧-脆混合性断裂转变。表明退火时间对多层复合钎料中间层宽度设定有重要影响,而中间层的相对宽度也影响钎料的使用性能。

Effect of annealing at 500℃for different time on the diffusion behavior of elements at the interface of AgCuZnNiMn/Cu/AgCuZnNiMn multilayer composite brazing filler metal and the mechanical properties of brazing were studied by means of scanning electron microscopy(SEM),energy dispersive spectrometer(EDS)and universal mechanical testing machine.The results show that the interface diffusion layer of the composite brazing filler metal is mainly silver-based solid solution and copper-based solid solution.With the increase of annealing time,the phase coarsens obviously,and the elements on both sides of the interface continue to diffuse.When the annealing time is 24 h,the thickness of the interface diffusion layer reaches 20μm.At the same time,with the increase of annealing time,the stress-released Cu layer at the interface of the brazed joint gradually decreases until it disappears,the strength of the joint decreases from 224 MPa to 165 MPa,and the fracture mechanism of the joint changes from ductile fracture dominated by dimples to ductile-brittle mixed fracture.It shows that annealing time has an important influence on the width of the interlayer of the multi-layer composite brazing filler metal,and the relative width of the interlayer also affects the service performance of the brazing filler metal.