形变热处理对用微量Cr合金化的Cu-Zn合金组织性能的影响  

Effects of thermomechanical heat treatment processing on microstructures and properties of Cu-Zn alloy by minor Cr alloying

作　　者：戴姣燕[1] 尹志民[1] 宋练鹏[1] 张生龙[1] 李雪[1] 孙伟[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《中国有色金属学报》2006年第6期982-988,共7页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(50371106);中南大学博士生创新基金资助项目

摘　　要：用中频熔炼半连续铸锭技术制备了一种成分为Cu-2Zn-0.6Cr的合金,铸锭经热挤压成28 mm×8 mm的条材并进行在线水淬,之后对条材分别实施时效和冷拉变形时效两种处理,冷拉变形量为35%。测试了合金的拉伸力学性能和电学性能,用金相、X射线衍射和电子显微分析研究了不同处理态合金的微观组织结构及其变化。研究结果表明:研究合金有很强的时效强化效应和优良的中温特性;时效前的预泠变形可以显著提高合金的强度,强度增量达到130 MPa;这种合金最佳的形变热处理工艺为在线固溶-35%冷拉变形-450℃下时效4 h,在此条件下合金抗拉强度和屈服强度分别达到467 MPa和390 MPa,延伸率和电导率分别达到20.8%和64.5%IACS。显微组织结构分析结果表明,形变热处理状态的合金力学性能和电学性能由时效过程中的回复再结晶和时效析出两个过程控制,合金的高强度主要来源于预冷变形引起的亚结构强化和Cr粒子的析出强化。An Cu-2Zn-0.6Cr alloy was prepared using intermediate frequency melting and semi-continuous casting. The ingots were extruded into bands with dimension of 28 mm × 8 mm which were then immediately immersed into water. The extrusion ratio was 15 ： 1. After extrusion, the bands were 35% cold-drawn and then aged under different conditions. The effects of aging temperature and time on mechanical and electrical properties of the alloy, which were processed using solution-aging and solution-35%cold drawing-aging, respectively, were studied. The results show that, firstly, the alloy has strong aging strengthening effect and good performance at intermediate temperature; secondly, cold-drawing prior to aging can significantly increase the strength of the alloy; thirdly, the optimum treatment is proved to he solution treatment followed by 35 % cold-drawing and then aged at 450 ℃ for 4 h, under which the tensile strength, yield strength, elongation and electrical conductivity of 467 MPa, 390 MPa, 20.8%and 64.5%IACS, respectively, were obtained. It is shown that the properties of the alloy are controlled by reversion-recrystallization and precipitation during the aging process. Substructure strengthening due to cold-drawing deformation and precipitation strengthening by the Cr particles precipitation are responsible for the high strength of the studied alloy.

关 键 词：铜合金 Cr合金化 形变热处理 组织 力学性能 

分 类 号：TG146.1[一般工业技术—材料科学与工程] TG146.3[金属学及工艺—金属材料]