超低温等通道转角挤压高导电单晶铜的霍尔佩奇强化  

Hall-Petch Strengthening in Single Crystal Copper with High Conductivity During Cryo-ECAP

作　　者：郭廷彪[1,2] 冯瑞 李凯哲 高洋[1] 钱丹晨 贾智[1,2] 丁雨田 凌得魁[3,4] Guo Tingbiao;Feng Rui;Li Kaizhe;Gao Yang;Qian Danchen;Jia Zhi;Ding Yutian;Ling Dekui(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Jinchuan Group Co.,Ltd,Jinchang 737100,China;State Key Laboratory of Nickel and Cobalt Resource Comprehensive Utilization,Jinchang 737100,China)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,甘肃兰州730050 [2]兰州理工大学材料科学与工程学院,甘肃兰州730050 [3]金川集团股份有限公司,甘肃金昌737100 [4]镍钴共伴生资源开发与综合利用全国重点实验室,甘肃金昌737100

出　　处：《稀有金属材料与工程》2023年第7期2396-2403,共8页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China (51861022, 51261016);2020 Key Talent Projects of Gansu。

摘　　要：分别采用光学显微镜、扫描电镜、X射线衍射仪和电子背散射衍射分析超低温等通道转角挤压(ECAP)中等应变量单晶铜的形变组织和织构演变,测试材料的力学和导电性能,分析材料组织转变机理及其对材料力学和导电性能的影响。结果表明,超低温ECAP早期形成的定向剪切带在后续变形过程中会严重影响材料组织的转变过程。增加应变量,A路径变形中剪切带内部会形成高密度的位错塞积,特征晶界占比增加;B_(C)路径变形时剪切带内部的位错发生强烈的交互作用;C路径变形后剪切带的取向发生分散。经过6道次变形后,单晶铜组织中形成强烈的{111}<112>织构,材料强度从初始126.0 MPa增加到400.2 MPa,而导电率仍保持在98%IACS以上。低温ECAP变形后组织内部形成定向剪切带并产生高密度的位错,位错间相互缠结,有效阻碍了位错滑移,而晶粒仍保持良好的单晶特性。The deformation microstructure and texture evolution of single crystal copper after cryogenic equal channel angular pressing(Cryo-ECAP) process were characterized by optical microscope,scanning electron microscope,X-ray diffractometer,and electron backscatter diffraction.The mechanical properties and conductivity properties were analyzed.The microstructure transition mechanism and its effects on the mechanical properties and conductivity properties were discussed.Results show that the directional shear bands formed in the early stage of Cryo-ECAP process seriously affect the microstructure transformation during the subsequent deformation.With increasing the strain,a high-density dislocation pile-up is formed in the shear bands during deformation by route A,and the proportion of characteristic grain boundaries is increased.The dislocations in the shear bands during deformation by route BC present strong interactions,and the orientation of shear bands is dispersed after the deformation by route C.After 6 passes of deformation,the strong {111} 112 texture forms in the microstructure of single crystal copper,the strength increases from 126.0MPa to 400.2 MPa,and the conductivity remains of above 98%IACS.After Cryo-ECAP,the directional shear bands form in the texture and the high-density dislocations are produced.The entanglement of dislocations effectively prevents the dislocation slip,and therefore the grains maintain the characteristics of single crystal.

关 键 词：单晶铜 超低温等通道转角挤压 微观组织 织构 力学性能 导电率 

分 类 号：TG146.11[一般工业技术—材料科学与工程]