Co颗粒含量对SnBi/Cu接头微观组织与性能的影响EI北大核心CSCD

采用扫描电镜(SEM)观察Sn35Bi-x Co(x=0%,0.3%,0.7%,1.0%,1.2%,1.5%,质量分数,下同)复合钎料/Cu接头的微观组织,结合能谱(EDS)和XRD分析,研究接头组织差异。利用万能试验机测试接头力学性能,研究Co颗粒含量对SnBi/Cu接头组织及性能的影响机制。结果表明:随Co颗粒含量增加,Sn35Bi-Co复合钎料的润湿性呈现先增大后降低的趋势,当Co颗粒含量为0.7%时,润湿性最佳;在凝固阶段,向Sn35Bi/Cu接头中加入适量的Co颗粒后,能有效细化焊缝组织,界面IMC层更为平坦,焊缝中Co原子置换界面Cu_(6)Sn_(5)层中Cu原子,生成(Cu,Co)_(6)Sn_(5)固溶体,对界面IMC层具有固溶强化作用;Sn35Bi-Co/Cu接头的抗剪强度随Co颗粒含量增加先增大后降低,当Co颗粒含量为0.7%时,获得最大值54.09 MPa。

Effect of Co particle content on microstructure and properties of SnBi/Cu joints

The microstructure of Sn35Bi-xCo(x=0%, 0.3%, 0.7%, 1.0%, 1.2%, 1.5%, mass fraction) composite solder/Cu joints was observed by scanning electron microscopy (SEM).Combined energy spectrum (EDS) and XRD analysis, the difference of joint structure was studied. The mechanical properties of joints were tested by universal testing machine, and the influence mechanism of Co particle content on the structure and properties of SnBi/Cu joints was studied. The results show that, with the increase of Co particle content, the wettability of Sn35Bi-Co composite solder increases first and then decreases. When Co particle content is 0.7%, the wettability is the best.When appropriate amount of Co particles is added to the Sn35Bi/Cu joint in the solidification stage, the weld microstructure can be effectively refined, the IMC layer of the interface is more flat, Co atoms in the weld replace Cu atoms in the interface Cu₆Sn₅ layer, and the (Cu, Co)₆Sn₅ solid solution can be formed, which can strengthen the IMC layer of the interface.The shear strength of Sn35Bi-Co/Cu joints increases first and then decreases with the increase of Co particle content. When Co particle content is 0.7%, the maximum value of 54.09 MPa is obtained.