冷拉拔导致的大塑性变形对定向凝固Cu-4 mass%Ag合金组织和性能的影响  

Effect of large plastic deformation caused by cold-drawing on microstructure and properties of directional solidification Cu-4 mass%Ag alloy

作　　者：张朝民 宋克兴[1,2] 程楚 周延军[1,2] 米绪军 李周[4] 肖柱[4] 孔令宝 康军伟 袁鹏飞 ZHANG Chao-min;SONG Ke-xing;CHENG Chu;ZHOU Yan-jun;MI Xu-jun;LI Zhou;XIAO Zhu;KONG Ling-bao;KANG Jun-wei;YUAN Peng-fei(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471023,China;Henan Key Laboratory of Non-ferrous Materials Science&Processing Technology,Luoyang 471023,China;GRIMAT Engineering Technology Institute Co Ltd,Beijing 100088,China;School of Materials Science and Engineering,Central South University,Changsha 410083,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023 [2]河南省有色金属材料科学与加工技术重点实验室,河南洛阳471023 [3]有研工程技术研究院有限公司,北京100088 [4]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《材料热处理学报》2020年第12期49-56,共8页Transactions of Materials and Heat Treatment

基　　金：国家重点研发计划(2016YFB0301400);河南省创新引领专项(191110210400);河南省杰出人才创新基金(182101510003);河南省高等学校重点科研项目(19A430012);洛阳市科技重大专项(1901006A);河南省科技攻关项目(202102210207);中国博士后科学基金第67批面上资助(2020M672222)。

摘　　要：采用三级真空加惰性气体保护冷型竖引连铸技术制备了定向凝固Cu-4 mass%Ag合金铸态杆坯,其线径约为7.8 mm。室温下利用多道次连续冷拉拔无中间退火的方法制备了Cu-4 mass%Ag合金键合线,最小线径为0.02 mm。研究了冷拉拔对Cu-4 mass%Ag合金的力学性能、电学性能以及微观组织的影响。结果表明:合金具有近轴向的柱状晶组织;随真应变增加,合金的抗拉强度显著增加,伸长率先急剧下降后保持平稳;在真应变为1~5时,合金强度的增加与柱状晶组织细化有关,真应变大于5时,细晶强化的作用减弱;合金的电导率随真应变增加先逐渐下降后略微增加,在真应变为9.0时,电导率为最小;电阻率随真应变增加先缓慢上升后下降,之后又略微上升,直流电阻则一直呈现显著增加趋势。Directional solidification Cu-4 mass%Ag alloy as-cast bar billet with diameter of about 7.8 mm was prepared by three-stage vacuum and inert gas cold-mold vertical continuous casting technology.The bonding line of the Cu-4 mass%Ag alloy was prepared by multi-pass continuous cold drawing without intermediate annealing at room temperature,and its minimum diameter was 0.02 mm.Effects of cold drawing on mechanical properties,electrical properties and microstructure of the Cu-4 mass%Ag alloy were studied.The results show that the alloy has nearly-axis columnar grains.With the increase of true strain,the ultimate tensile strength of the alloy increases significantly,and the elongation first decreases sharply and then remains stable.When the true strain is 1-5,the increase of the ultimate tensile strength of the alloy is related to the refinement of columnar grains,and when the true strain is greater than 5,the effect of refined grain strengthening is weakened.With the increase of true strain,the electrical conductivity of the alloy decreases gradually first and then increases slightly,and when the true strain is 9.0,the electrical conductivity is the minimum.With the increase of true strain,the electrical resistivity of the alloy increases slowly first and then decreases,then increases slightly,while the direct current resistance always has a significant increasing tendency.

关 键 词：Cu-4 mass%Ag合金 定向凝固 柱状晶组织 高强高导 冷拉拔 

分 类 号：TG146.1[一般工业技术—材料科学与工程]