(重庆大学 材料科学与工程学院，重庆 400044)
摘 要: 利用单棍快淬工艺制备快速凝固态Sn-6.5Zn合金薄带，对比分析快速凝固制备工艺对钎料微观结构、熔化与铺展特性的影响，并利用拉伸−剪切试验对比研究了钎料/Cu焊点力学性能。结果表明：快速凝固能够显著细化Sn-6.5Zn合金微观组织，初生β-Sn相快速分枝并形成网状枝晶结构，Zn相呈尺寸为0.5~2 μm的细小颗粒分布于β-Sn基体中；经快速凝固后，Sn-6.5Zn合金熔化区间减小了约3.7 ℃；快速凝固态Sn-6.5Zn合金具有优于常态钎料的钎焊工艺性能，能够促进钎料/Cu焊点形成均匀界面并改善力学性能。
关键字: 快速凝固；Sn-6.5Zn钎料；焊点；微观结构；力学性能
（College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China）
Abstract:The rapidly solidified Sn-6.5Zn alloy foils were prepared by melt-spinning method. Through comparison, the effects of rapid solidification process on the microstructure, thermodynamic characteristic and spreading properties of Sn-6.5Zn solder alloys were analyzed. The tensile-shear tests were used to evaluate the mechanical properties of solder/Cu joints. The results show that the rapid solidification process can greatly refine the solidification structure of Sn-6.5Zn alloy. A netlike dendrite structure is formed due to the rapid branch of β-Sn and the Zn phases are distributed in β-Sn matrix in granular form with size of 0.5−2 μm. After rapid solidification, the pasty range is reduced by about 3.7 ℃. The rapidly solidified Sn-6.5Zn alloy has an excellent wettability under test compared with as-solidified solder. The mechanical properties of solder/Cu joints are also obviously improved by using the rapidly solidified Sn-6.5Zn solder alloy, which results in the formation of uniform interface.
Key words: rapid solidification; Sn-6.5Zn solder; soldering joint; microstructure; mechanical properties
