Effects of rapid solidification on the microstructure and microhardness of a lead-free Sn-3.5Ag solder  

作　　者：SHEN Jun LIU Yongchang Han Yajing GAO Houxiu 

机构地区：[1]College of Mechanical Engineering, Chongqing University, Chongqing 400044, China [2]College of Materials Science and Engineering, Tianjin University, Tianjin 300072, China

出　　处：《Rare Metals》2006年第4期365-370,共6页稀有金属（英文版）

基　　金：This work was financially supported by the National Natural Science Foundation of China (No. 50401003), the Natural Science Foundation of Tianjin City (No. 033608811) and Fok Ying Tong Education Foundation (No. 104015).

摘　　要：A lead-free Sn-3.5Ag solder was prepared by rapid solidification technology. The high solidification rate, obtained by rapid cooling, promotes nucleation, and suppresses the growth of Ag3Sn intermetallic compounds （IMCs） in Ag-rich zone, yielding fine Ag3Sn nanoparticulates with spherical morphology in the matrix of the solder. The large amount of tough homogeneously-dispersed IMCs helps to improve the surface area per unit volume and obstructs the dislocation lines passing through the solder, which fits with the dispersion-strengthening theory. Hence, the rapidly-solidified Sn-3.5Ag solder exhibits a higher rnicrohardness when compared with a slowly-solidified Sn-3.5Ag solder.A lead-free Sn-3.5Ag solder was prepared by rapid solidification technology. The high solidification rate, obtained by rapid cooling, promotes nucleation, and suppresses the growth of Ag3Sn intermetallic compounds （IMCs） in Ag-rich zone, yielding fine Ag3Sn nanoparticulates with spherical morphology in the matrix of the solder. The large amount of tough homogeneously-dispersed IMCs helps to improve the surface area per unit volume and obstructs the dislocation lines passing through the solder, which fits with the dispersion-strengthening theory. Hence, the rapidly-solidified Sn-3.5Ag solder exhibits a higher rnicrohardness when compared with a slowly-solidified Sn-3.5Ag solder.

关 键 词：lead-free solder nanoparticulate rapid solidification intermetallic compounds dispersion-strengthening effect 

分 类 号：TG40[金属学及工艺—焊接]