二次时效变形对Cu-Zr合金组织和性能的影响  

Effect of Two-Step Aging and Deformation on Microstructure and Properties of Cu-Zr Alloy

作　　者：王景皓 蒋尧 诸叶斌 古睿聪 刘瑛[1] 王经涛[1,2] Wang Jinghao;Jiang Yao;Zhu Yebing;Gu Ruicong;Liu Ying;Wang Jintao(School of Materials Science and Engineering,Nanjing University of Science and Technology,Nanjing 210094,China;Herbert Gleiter Institute of Nanoscience,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学材料科学与工程学院,江苏南京210094 [2]南京理工大学格莱特纳米科技研究所,江苏南京210094

出　　处：《稀有金属》2019年第10期1032-1039,共8页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51520105001);国家重点基础研究发展计划项目(2012CB932200)资助

摘　　要：微观缺陷是金属材料机械、物理性能的重要调控媒介。基于微观缺陷调控设计和Zr元素微合金化,利用多道次大塑性变形与时效工艺结合制备了一种高强度、高导电性的Cu-0.08%(质量分数)Zr合金。使用电子背散射衍射仪(EBSD)和透射电子显微镜(TEM)表征合金在制备过程中微观组织的演化,并对Cu-Zr合金的机械、物理性能进行测试。组织表征表明:通过添加微量Zr元素, Cu-Zr合金先是从等径角变形(ECAP)的过饱和固溶体转变为一次时效后的Zr偏析稳定的超细晶合金,接着通过低温轧制制备出纳米尺度的Cu-Zr合金片层组织。性能测试表明, Cu-Zr合金经过EACA(ECAP+aging+cryo-rolling+aging,简称为EACA)处理后获得高硬度(HV 192.6)和高电导率(82.5%IACS)的良好搭配。分析认为,其高强度来源于细晶强化、偏析强化和退火强化等多强化机制的耦合,而高导电性则是由于基体内部低的元素固溶量和低的晶格畸变。本文为高电导Cu合金的强化提供一种新的设计思路,有望在工业生产中实现大规模应用。Defects are the key to control both mechanical and physical properties of metallic materials. Based on intrinsic defect manipulation and micro-alloying with Zr, Cu-0.08%(mass fraction) Zr alloy of high strength and high electrical conductivity was prepared using multiple severe plastic deformation and aging method. Electron backscatter diffraction(EBSD) and transmission electron microscopy(TEM) were used to characterize microstructural evolution during preparation, and mechanical and physical properties were also tested. The results showed that with the addition of Zr, Cu-Zr alloy changed from super-saturated solid solution after equal-channel angular pressing(ECAP) into ultrafine grained alloy with Zr segregation after aging, then the Cu-Zr alloy structure of nano-lamellar was prepared by cryo-rolling. It demonstrated that Cu-Zr alloy possessed high hardness(HV 192.6) and high electrical conductivity(82.5% IACS) after EACA(ECAP+aging+cryo-rolling+aging, EACA). It was found that the high strength originated from the combination of fine-grained strengthening, twin boundary strengthening and "strengthening by annealing", while the high electrical conductivity was due to low element solid solution and lattice distortion in the grain interior. The study offered a novel design approach for strengthening Cu-based alloys, which could be efficaciously utilized into manufacturing production.

关 键 词：CU-ZR合金 微合金化 微观缺陷 偏析 退火强化 

分 类 号：TG146.1[一般工业技术—材料科学与工程]