Mg颗粒强化对Sn58Bi/Cu焊点金属间化合物生长及机械性能的影响机理研究  

Study on the Growth of Intermetallic Compounds in Mg Particle-Reinforced Sn58Bi/Cu Solder Joints and the Mechanism of Mechanical Property Influence

作　　者：饶丽斌 黄玺 张亮 RAO Libin;HUANG Xi;ZHANG Liang(Xiamen Hongfa Electric Power Control Co.,Ltd.,Xiamen 361026,China;School of Materials Science and Engineering,Xiamen University of Technology,Xiamen 361024,China)

机构地区：[1]厦门宏发电力电器有限公司,福建厦门361026 [2]厦门理工学院材料科学与工程学院,福建厦门361024

出　　处：《电焊机》2024年第5期25-30,共6页Electric Welding Machine

基　　金：厦门理工学院高层次人才科研启动项目(YKJ22054R)。

摘　　要：采用机械混合的方法将Mg颗粒成功添加到Sn58Bi无铅钎料中,制备了一种新型复合钎料Sn58Bi-xMg(x=0,0.2,0.4,0.6,0.8,1.0)。针对该复合钎料在Cu衬底上形成焊点的显微组织和界面金属间化合物(IMC)的生长情况进行了深入观察与研究。试验结果表明,加入Mg颗粒起到了细化组织的作用,同时基体中均匀分散的Mg颗粒还抑制了Bi相的析出,有助于提高焊点的细化度和整体强度。随着Mg颗粒含量的增加,IMC层厚度逐渐减小,当Mg颗粒的添加量为0.4 wt.%时达到最低值,仅为3.03μm。值得注意的是,当Mg颗粒含量超过0.4 wt.%时,由于大粒径的Mg颗粒易发生团聚并容易氧化,导致强化效果不太理想。通过对IMC晶粒生长情况的观察,验证了Mg颗粒的引入能够成功细化IMC晶粒,从而实现细晶强化,提高焊点的整体强度。另外,与未添加Mg颗粒的焊点相比,Sn58Bi-0.4Mg焊点的抗剪强度提高了36.87%。此外,断口处出现韧窝也表明焊点的延展性得到明显提升。This study employed a mechanical mixing method to successfully incorporate Mg particles into the lead-free sol‐der Sn58Bi,resulting in a novel composite solder Sn58Bi-xMg(x=0,0.2,0.4,0.6,0.8,1.0).In-depth observation and investi‐gation were conducted regarding the microstructure of the solder joints formed by these composite solders on Cu substrates and the growth of intermetallic compounds(IMCs)at the interfaces.The experimental results indicated that the introduction of Mg particles played a role in refining the microstructure of the solder joints.Simultaneously,the uniformly dispersed Mg particles in the matrix also suppressed the precipitation of Bi phases,contributing to the enhancement of solder refinement and overall strength.With the increase in Mg particle content,the thickness of IMC gradually decreased.Particularly,when the addition of Mg particles was 0.4 wt.%,the IMC thickness reached its minimum at only 3.03μm.It is noteworthy that when the Mg particle content exceeded 0.4 wt.%,the larger-sized Mg particles were prone to aggregation and oxidation,leading to a less-than-satisfactory strengthening effect.Through observations of the growth of IMC grains,it was verified that the introduction of Mg particles successfully refined the IMC grains,achieving a fine-grain strengthening effect and im‐proving the overall strength of the solder joints.Compared to solder joints without added Mg particles,the shear strength of Sn58Bi0.4Mg solder joints increased by 30%.Additionally,the appearance of ductile dimples on the fracture surface indi‐cated a significant improvement in the ductility of the solder joints.These research findings provide new insights and meth‐ods for the improvement of soldering technology.

关 键 词：Mg颗粒 Sn58Bi无铅钎料 机械性能 金属间化合物 

分 类 号：TG425[金属学及工艺—焊接]