摘要
利用扫描电子显微镜(SEM)、能谱分析仪(EDX)、电子拉伸试验机对Bi-xAg-0.4Ni-0.2Cu-0.1Ge(x=2,5,8,11,14)高温无铅钎料/铜接头进行了界面微观组织分析、抗剪强度测试及剪切断口分析.结果表明,界面微观组织由初生Ag原子、初晶Bi原子和共晶组织组成,还有少量的NiBi3相.随着钎料中Ag元素含量的提高,微观组织中初生Ag原子数量逐渐增多,宏观性能上接头抗剪强度提高.初生Ag原子能够阻碍钎料中裂纹的扩展,使得接头的强度提高.钎料与铜基板之间没有金属间化合物生成,它们之间的连接主要是通过液态钎料原子向铜基板晶界扩散.钎料中的Bi原子向铜基板晶界的扩散程度高于Ag原子.钎料与铜基板界面的连接处为接头薄弱区,是剪切断裂的起点.
The microstructure,joint shear strength and fracture surface of high-temperature lead-free solder Bi-xAg-0.4Ni-0.2Cu-0.1Ge(x=2,5,8,11,14) were analyzed with scanning electron microscopy,energy dispersive X-ray spectrometry and electronic tensile testing machine.The results show that interface microstructure mainly consists of primary Ag,primary crystal Bi,eutectic phase and little NiBi3 phase.With the increasing of Ag in solder,primary Ag increases gradually and shear strength heightens obviously.No intermetallic compound forms between solder and Cu substrate,which join mainly through the diffusion of liquid solder atoms to Cu crystal boundaries.The diffusion of Bi to Cu crystal boundary is more than that of Ag.The interface between solder and Cu substrate is the weak region of joint and is shear fracture starting point.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2009年第10期45-48,共4页
Transactions of The China Welding Institution
