高强高导Cu-Mg-Ca合金加工过程中组织结构演变  

Microstructure and mechanical properties evolution of high strength and high electrical conductivity Cu-Mg-Ca alloy during manufacture process

作　　者：李亚萍 肖柱[1] 雷前[1] 周哲远 李周[1,2] LI Ya-ping;XIAO Zhu;LEI Qian;ZHOU Zhe-yuan;LI Zhou(School of Materials Science and Engineering, Central South University, Changsha 410083, China;State Key Laboratory of Powder Metallurgy, Changsha 410083, China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]粉末冶金国家重点实验室,长沙410083

出　　处：《中国有色金属学报》2018年第3期547-555,共9页The Chinese Journal of Nonferrous Metals

基　　金：国家重点基础研究发展计划资助项目(2016YFB0301300);国家自然科学基金重点项目(U1637210)~~

摘　　要：利用硬度计、双臂电桥、金相显微镜、透射电镜和背散射电子衍射观察等技术研究Cu-0.3Mg-0.16Ca(质量分数,%)合金在加工过程中组织结构的演变规律及性能变化。结果表明:设计合金经780℃、1h固溶处理后冷轧变形状80%时,硬度为167HV,抗拉强度为545MPa,电导率70.24%IACS;当变形量达到90%时,硬度为174HV,抗拉强度为600MPa,电导率为68.68%IACS,均高于同状态下的高铁接触线用CTMH型Cu-0.4Mg合金的性能。设计合金固溶态组织为以大角度晶界为主的等轴晶,所占比例最高的是60°的大角度晶界;随着冷变形的进行,合金组织中开始出现分布不均匀的小角度晶界,随着变形量的进一步增加,小角度晶界先增多后减少。当变形量达到80%时,合金轧面的变形织构以S剪切织构和Copper织构为主,此时合金显微组织中的变形条带发生弯曲,向胞状组织过渡。The microstructure evolution of the designed Cu-0.3Mg-0.16Ca（mass fraction, %） alloy was studied by metallographic microscopy, transmission electron microscopy and electron backscattered diffractometry. The result shows that, after being homogenized at 780℃ for 1h, followed by cold rolling with a reduction of 80%, the designed alloy shows prospective comprehensive properties with tensile strength of 545MPa and electrical conductivity of 70.24%IACS. When being cold-rolled to 90% reduction, the tensile strength and electrical conductivity of Cu-0.3Mg-0.16Ca（mass fraction, %） alloy approach 600 MPa and 68.68%IACS, respectively, which are both higher than those of CTMH Cu-0.4Mg alloy that is commonly used in high-speed railway contact wires. The fraction of low-angle grain boundaries of the alloy increases and then decreases with the increase of deformation. After a cold rolling reduction of 80%, the textures of S and Copper are predominatant.

关 键 词：Cu-Mg-Ca合金 高强度 高电导率 显微组织 

分 类 号：TG146[一般工业技术—材料科学与工程]