冷拉拔变形对纯铜组织及性能的影响  

Effect of cold drawing deformation on the microstructure and properties of pure copper

作　　者：刘若絮 毛西秦 欧梅桂[1,2] 梁宇 肖秋雷[3] LIU Ruoxu;MAO Xiqin;OU Meigui;LIANG Yu;XIAO Qiulei(College of Materials and Metallurgy,Guizhou University,Guiyang 550025,China;National Local Joint Engineering Laboratory for High Performance Metal Structure Materials and ManufacturingTechnology,Guiyang 550025,China;Guda Wire and Cable(Group)Co.,Ltd.,Anshun 561000,Guizhou,China)

机构地区：[1]贵州大学材料与冶金学院,贵阳550025 [2]高性能金属结构材料与制造技术国家地方联合工程实验室,贵阳550025 [3]固达电线电缆(集团)有限公司,贵州安顺561000

出　　处：《有色金属科学与工程》2022年第2期67-75,共9页Nonferrous Metals Science and Engineering

基　　金：贵州省科学技术项目(黔科合支撑[2019]2165号);贵州省教育厅工程研究中心项目(黔教合KY字[2017]016)。

摘　　要：通过工业拉丝机对纯铜棒材进行多道次冷拉拔得到不同变形量的线材。对不同变形量的线材试样进行退火实验(400℃,1 h),研究组织形貌变化对其力学性能和电学性能的影响。试样的变形量由0增加至60%时,在拉拔方向上晶粒尺寸由101.3μm下降至17.6μm,截面方向上晶粒尺寸由103.4μm下降至16.4μm,晶粒呈现等轴状。变形量增加到90%时,在拉拔方向上晶粒尺寸为14.1μm,截面方向上晶粒尺寸为7.6μm,试样组织由变形晶粒和等轴晶粒组成。变形量由0增加至90%,试样的抗拉强度由221.5 MPa升至271.5 MPa;当变形量为60%时,其抗拉强度为244.9 MPa,延伸率达到最高值为51%,导电率为99.4%IACS。试样组织中晶粒的<111>+<100>取向比例与试样的延伸率成反比;通过原位拉伸观察表明,退火态试样的裂纹穿晶扩展,路径较曲折;而拉拔试样的裂纹萌生于变形晶粒内部,裂纹扩展路径较为平直。Wires with different deformations were obtained by multipass cold drawing of a pure copper bar by an industrial wire drawing machine. The annealing experiments were carried out at 400 ℃ for 1 h to study the effects of microstructure changes on the mechanical and electrical properties of wires with different deformations. When the deformation of the samples increased from 0 to 60%, the grain size in the drawing direction(DD) decreased from 101.3 μm to 17.6 μm, the grain size in the transverse direction(TD) decreased from 103.4 μm to 16.4 μm, and the grain size was equiaxed. When the deformation amount increased to 90%,the grain size in the drawing direction was 14.1 μm, and the grain size in the section direction was 7.6 μm. The specimen microstructure consisted of deformed grains and equiaxed grains. When the deformation increased from 0 to 90%, the tensile strength increased from 221.5 MPa to 271.5 MPa. When the deformation was 60%,the tensile strength was 244.9 MPa, the elongation reached the highest value of 51%, and the electrical conductivity was 99.4% IACS. The orientation ratio of <111>+<100> in the samples was inversely proportional to the elongation of the samples. The in situ tensile observation showed that the crack propagation path was more tortuous in the process of cracks crossing the grain boundary for annealed samples. For the drawn samples, crack initiation occurred in the deformed grain, and the crack propagation path was relatively straight.

关 键 词：纯铜 拉拔变形 热处理 力学性能 裂纹扩展 

分 类 号：TG166.2[金属学及工艺—热处理] TF125.211[金属学及工艺—金属学]