(重慶大學(xué) 材料科學(xué)與工程學(xué)院，重慶 400044)
摘 要: 利用單棍快淬工藝制備快速凝固態(tài)Sn-6.5Zn合金薄帶，對(duì)比分析快速凝固制備工藝對(duì)釬料微觀結(jié)構(gòu)、熔化與鋪展特性的影響，并利用拉伸−剪切試驗(yàn)對(duì)比研究了釬料/Cu焊點(diǎn)力學(xué)性能。結(jié)果表明：快速凝固能夠顯著細(xì)化Sn-6.5Zn合金微觀組織，初生β-Sn相快速分枝并形成網(wǎng)狀枝晶結(jié)構(gòu)，Zn相呈尺寸為0.5~2 μm的細(xì)小顆粒分布于β-Sn基體中；經(jīng)快速凝固后，Sn-6.5Zn合金熔化區(qū)間減小了約3.7 ℃；快速凝固態(tài)Sn-6.5Zn合金具有優(yōu)于常態(tài)釬料的釬焊工藝性能，能夠促進(jìn)釬料/Cu焊點(diǎn)形成均勻界面并改善力學(xué)性能。
關(guān)鍵字: 快速凝固；Sn-6.5Zn釬料；焊點(diǎn)；微觀結(jié)構(gòu)；力學(xué)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
