高导热低膨胀石墨/Cu-Zr复合材料组织与性能  

Microstructure and properties of graphite/Cu-Zr composites with high thermal conductivity and low coefficient of thermal expansion

作　　者：陈存广 崔倩月 余程巍 郝俊杰 郭志猛 CHEN Cunguang;CUI Qianyue;YU Chengwei;HAO Junjie;GUO Zhimeng(Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519000,China;Beijing Tianyishangjia New Material Co.,Ltd,Beijing 102206,China)

机构地区：[1]北京科技大学新材料技术研究院,北京100083 [2]南方海洋科学与工程广东省实验室(珠海),广东珠海519000 [3]北京天宜上佳高新材料股份有限公司,北京102206

出　　处：《中南大学学报（自然科学版）》2020年第11期3072-3080,共9页Journal of Central South University:Science and Technology

基　　金：国家重点研发计划项目(2016YFB1101201);中央高校基本科研业务费专项资金资助项目(FRF-GF-19-012AZ)。

摘　　要：为解决导热鳞片石墨/Cu复合材料中石墨取向及Cu-C界面结合弱的难题,将Zr元素引入铜基体中作为碳化物形成元素,以优化Cu-C界面,并采用流延法和热压烧结工艺协同制备高取向石墨/Cu复合材料。研究结果表明:流延法是使鳞片石墨在基体中获得高排列取向度的有效手段;Cu-C界面处形成ZrC,界面结合更加紧密;复合材料热导率随Zr加入量的增加先增大后减小,Zr质量分数为0.5%时达到最大值604 W/(m·K),与纯Cu相比,热导率提高52%;复合材料在Z方向出现负膨胀现象,随着Zr质量分数的增加,XY平面热膨胀系数不断降低,Z方向的热膨胀系数逐渐接近半导体的热膨胀系数;当Zr质量分数增加到2.0%,复合材料的抗弯强度相对于未加Zr的复合材料提高了42%,鳞片石墨的层间剥离和脱落是导致复合材料发生断裂的主要原因。To overcome the technical difficulties of graphite orientation and weak Cu-C interface bonding in flake graphite/Cu composites,Zr was introduced into the Cu matrix as carbide forming element,optimizing the combination of interface phase.The highly-oriented flake graphite/Cu composite was prepared by tape-casting and hot-pressing sintering.The results show that tape-casting is an effective method to obtain high alignment of the flake graphite in the matrix.ZrC is formed at the Cu-C interface,contributing to the tighter interface bonding.The thermal conductivity(TC)of the composite increases first and then decreases with the increase of the Zr content.The maximum value of the TC of the composite with 0.5%Zr(mass fraction)is 604 W/(m·K),which is 52%higher than that of pure Cu.The composite exhibits a negative expansion phenomenon in the Z direction.With the increase of Zr content,the coefficient of thermal expansion(CTE)in the XY direction continues to decrease,and the CTE in the Z direction gradually approaches that of semiconductor.The flexural strength of the composite with 2.0%Zr(mass fraction)is increased by 42%compared to the composite without Zr.The exfoliation between graphite layers is the main reason for the fracture of composites.

关 键 词：铜基复合材料 鳞片石墨 锆 高取向 负膨胀 

分 类 号：TB333[一般工业技术—材料科学与工程]