(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083；
2. 中南大學(xué) 有色金屬材料科學(xué)與工程教育部重點(diǎn)實(shí)驗室，長沙 410083)
摘 要: 采用力學(xué)性能測試、光學(xué)顯微鏡、掃描電鏡和能譜分析技術(shù)及切削性能測試對自行研制的含Bi易切削變形Zn-Cu合金鑄態(tài)及擠壓態(tài)的組織與性能進(jìn)行研究。結(jié)果表明：Mn在Zn-Cu合金中易形成大而硬的塊狀相，對于提高鋅合金的綜合力學(xué)性能作用不明顯，且可能產(chǎn)生不良影響；低熔點(diǎn)Bi相在Zn-Cu合金中鑄態(tài)時以針狀彌散分布，擠壓態(tài)時以點(diǎn)狀彌散分布，改善了Zn-Cu合金的切削性能；自行配制的Zn-1.2%Cu-0.5%Bi-X合金，切削性能良好，抗拉強(qiáng)度達(dá)到405 MPa，伸長率為19.0%，表現(xiàn)出較優(yōu)的綜合性能，可作為部分銅合金替代材料，用于制造軸承、連接件、五金和家電等結(jié)構(gòu)件。
關(guān)鍵字: 變形鋅合金；Bi；顯微組織；切削性能
free-cutting deformation Zn-Cu-Bi alloy
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering,
Ministry of Education, Central South University, Changsha 410083, China）
Abstract:The microstructure and properties of self-developed Zn-Cu-Bi alloys in the cast and extruded conditions were investigated by mechanical tests, optical microscope, scanning electron microscope, energy spectrum analysis and machinability tests. The results show that Mn can easily form large and hard massive structure in the Zn-Cu alloy, which cannot improve the mechanical properties of Zn-Cu alloy obviously, and may bring worse effects. The machinability of the Zn-Cu alloy can be improved by needle dispersion distributed low-melting Bi phase in the cast condition and dot-like dispersion distributed Bi phase in the extruded condition. The self-developed Zn-1.2%Cu-0.5%Bi-X alloy is of good machinability, and the tensile strength and elongation of the alloy reach 405 MPa and 19.0%, respectively, showing good comprehensive properties. The alloy can be used to replace some copper alloys for making bearings, connectors, household appliances and other structural parts.
Key words: deformation zinc alloy; Bi; microstructure; machinability
