纯铜包覆铝合金复合材料界面组织与性能研究  

Interfacial Microstructure and Properties of Copper Cladding Aluminum Alloy Composites

作　　者：檀晓轲 刘新华 解国良 Tan Xiaoke;Liu Xinhua;Xie Guoliang(Institute for Advanced Materials and Technologies,University of Science and Technology Beijing,Beijing 100083,China;State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学新材料技术研究院,北京100083 [2]北京科技大学新金属材料国家重点实验室,北京100083

出　　处：《稀有金属》2022年第7期862-872,共11页Chinese Journal of Rare Metals

基　　金：国家高新技术研究发展计划项目(2013AA030706)资助。

摘　　要：本文采用立式连铸直接复合的方法制备了直径为20 mm,铜包覆层厚度为2 mm的纯铜包覆铝合金(铜包铝合金)复合棒材,并通过扫描电子显微镜(SEM)、电子探针(EPMA)、能谱仪(EDS)和透射电子显微镜(TEM)等研究了Cu/Al界面的结构与相组成规律,提出了连铸复合铜包铝合金的界面模型及形成机制。结果表明,铜包铝合金复合材料界面层从铜包覆一侧到铝芯一侧主要由3个亚层构成,即靠近铜侧的Cu_(9)Al_(4)层(亚层I),厚度较为均匀,约3μm;中间层为CuAl_(2)层(亚层Ⅱ),呈胞状,厚度不均匀,在10~40μm之间;靠近铝芯一侧为α-Al+CuAl_(2)伪共晶组织(亚层Ⅲ),呈片层状分布,厚度较大,约为200μm,而且α-Al+CuAl_(2)伪共晶组织(亚层Ⅲ)中有铝合金中合金元素形成的复杂析出相和残存未转变的高温Cu_(3)Al_(2+x)相。纳米压痕实验结果表明,亚层I的显微硬度最高,平均值为7.26 GPa;亚层Ⅱ的硬度次之,平均值为5.77 GPa;亚层Ⅲ的硬度最低,平均值为2.39 GPa。界面结合强度测试的结果表明,铝合金中的合金元素在界面处偏聚形成的析出相略微降低了界面结合强度。Cu/Al composite conductor materials had many advanced properties,such as high conductivity,excellent heat conductivi⁃ty,good corrosion resistance,low density,and easy connectivity,low price compared with pure copper or copper alloys.It was widely used in aerospace,telecommunications,national defense industry and other fields.Continuous composite casting had the advantages of short process,high efficiency,low cost and near final shape and could realize metallurgical bonding of the Cu/Al interface.The pro⁃cessing difficulty of copper cladding aluminum alloy wires could be reduced by means of fabricating rods with smaller diameter by corefilling continuous composite casting technology.However,the smaller the diameter of the rod,the less metal in the core,the less heat of copper coating could be absorbed,and the higher reaction degree of the Cu/Al interface,resulting in a significant increase in the preparation difficulty.Therefore,it was necessary to explore more accurate and reasonable continuous casting process parameters and composite interface structure evolution law of different continuous casting process parameters.The copper cladding aluminum alloy rods with the section dimensions of 20 mm in diameter and 2 mm in sheath thickness were fabricated by vertical core-filling continuous casting technology.The samples with length of about 70 mm were taken from the copper cladding aluminum alloy rods bar for macro⁃scopic morphology observation by electrical discharge wire-cutting.Several samples with length of about 10 mm were taken from the copper cladding aluminum alloy rods for structure analysis,hardness test,bonding strength test by electrical discharge wire-cutting.The microstructure of the Cu/Al interface was investigated by scanning electron microscope(SEM),energy dispersive spectrometer(EDS),electro-probe microanalyzer(EPMA).Transmission electron microscopy(TEM)samples were prepared by ion thinning.The structure and phase composition of the Cu/Al interface were investigated by TEM.The hardness was test

关 键 词：铜包铝合金复合材料 显微组织 性能 界面形成模型 

分 类 号：TK91[动力工程及工程热物理]