(1. 华南理工大学 材料科学与工程学院，广州 510640； 2. 华南理工大学 机械与汽车工程学院，广州 510640； 3. 广东省先进储能材料重点实验室，广州 510640； 4. 广东水利电力职业技术学院，广州 510925)
摘 要: 采用机械合金化法制备出Cu-10%Sn-5%Bi合金粉末，然后将其压制成型并进行烧结，制备成合金块体；利用X射线衍射(XRD)和扫描电镜(SEM)等分析手段，研究Cu-Sn-Bi合金在高能球磨和烧结过程中组织结构的变化。结果表明：高能球磨可以扩展Cu-Bi互不溶体系的固溶度，且在球磨过程中形成的Cu6Sn5相为亚稳定相，随着球磨时间延长会先形成而后发生分解，分解后的Sn将固溶到Cu中；同时在450 r/min球磨40 h后，Sn、Bi基本完全融入Cu中，形成Cu的过饱和固溶体。在烧结过程中，Bi从Cu中脱溶，细小弥散分布在Cu基体中。在700 ℃二次烧结后，Cu-Sn-Bi合金显微组织良好，具有相对较好的力学性能。
关键字: 机械合金化；粉末烧结；Cu-Sn-Bi合金；过饱和固溶体
（1. School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China; 2. School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou 510640, China; 3. Key Laboratory of Advanced Energy Storage Materials of Guangdong Province, Guangzhou 510640, China; 4. Guangdong Polytechnic of Water Resources and Electric Engineering, Guangzhou 510925, China）
Abstract:The mechanical alloying (MA) was used to prepare Cu-10%Sn-5%Bi alloy powders. Then the bulk alloy was obtained by a combination of cold pressing and conventional powder sintering. The microstructure evolutions of Cu-10%Sn-5%Bi alloy during ball milling and sintering were investigated by XRD and SEM. The results show that high-energy milling can extend solid solubility of Cu-Bi immiscible system, and the metastable Cu6Sn5 phase successively happens to formation and decomposition with milling time. Meanwhile, the decomposition Sn is dissolved into Cu matrix. After milling with 450 r/min for 40 h, both Sn and Bi are completely dissolved into Cu matrix and a supersaturated solid solution of Cu(Sn, Bi) is formed. During sintering, Bi precipitates from Cu(Sn, Bi) supersaturated solid solution, are fine and dispersed homogeneously in Cu(Sn) matrix. The Cu-Sn-Bi alloy twice sintered at 700 ℃ exhibits an excellent microstructure and mechanical properties.
Key words: mechanical alloying; powder sintering; Cu-Sn-Bi alloy; supersaturated solid solution
