(1. 北京科技大学 材料先进制备技术教育部重点实验室，北京 100083； 2. 北京科技大学 现代交通金属材料与加工技术北京实验室，北京 100083)
摘 要: 采用旋锻-拉拔-扩散退火-拉拔方法制备直径60 μm金包铜复合微丝，研究拉拔过程中复合微丝显微组织、力学性能和导电率的变化规律。结果表明：所制备的微丝表面光洁和金/铜界面结合状态良好，金层平均厚度约为2.0μm，横断面金包覆层面积比约为10.5%。在拉拔过程中，当真应变增大至2.5时，复合微丝铜芯由退火态的等轴晶组织逐渐转变为条状纤维组织，晶内小角度晶界数量明显增大，微丝的抗拉强度由退火态的235 MPa增大至最大值451 MPa，而断后伸长率由退火态的49.5%降低至1.2%，导电率由100.0%(IACS)下降为98.3%(IACS)；继续增大真应变至3.5和4.8时，加工过程中产生的变形热使铜芯发生动态回复和动态再结晶，小角度晶界数量降低，大角度晶界数量增多；当真应变为4.8时，微丝的抗拉强度为439MPa，伸长率上升至3.0%，导电率下降到94.5%(IACS)。
关键字: 金包铜复合微丝；拉拔；界面；组织；性能
（1. Key Laboratory for Advanced Materials Processing, Ministry of Education, University of Science and Technology Beijing, Beijing 100083, China; 2. Beijing Laboratory of Metallic Materials and Processing for Modern Transportation, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:A method of rotary forging-drawing-diffusion annealing-drawing was proposed to produce d0.06 mm gold cladding copper micro-wire. The evolutions of the microstructure, mechanical properties and electrical conductivity of the micro-wire during drawing were studied. The results show that the prepared gold cladding copper micro-wire exhibits the smooth surface, good Au/Cu bonding interface, gold layer with an average thickness of 2.0 μm and cladding ratio of about 10.5%. During drawing, when the true strain increases to 2.5, the microstructure of the copper core changes from equiaxed grains of the annealed wire to fiber grains, and the number of low angle grain boundary increases significantly. The tensile strength of the composite wire increases from 235 MPa of the annealed wire to the maximum of 451 MPa, while the elongation to failure decreases from 49.5% of the annealed wire to 1.2%, and the electrical conductivity decreases from 100.00%(IACS) of the annealed wire to 98.3%(IACS). When the true strain increases to 3.5 and 4.8, the dynamic recovery and dynamic recrystallization occurs in the copper core due to deformation heat generated during drawing, the number of low angle grain boundary reduces while the number of high angle grain boundary increases. At the true strain of 4.8, the tensile strength of the composite wire is 439 MPa, the elongation increases to 3.0% and the electrical conductivity decreases to 94.5%(IACS).
Key words: gold cladding copper micro-wire; drawing; interface; microstructure; property
