粉末冶金法制备镀铜石墨烯/铝复合材料的组织与性能研究

Research on microstructure and properties of graphene-Cu/Al composite prepared by the powder metallurgy method

采用真空热压烧结法制备了分别添加体积分数为5%和10%镀铜石墨烯的铝基复合材料。通过金相显微镜、扫描电镜、X射线衍射仪、布氏硬度计、导热系数测试仪和四探针电阻率测试仪,检测了复合材料的组织、硬度、导热和导电性能。试验结果表明:采用简化的化学镀铜方法在石墨烯表面成功化学镀铜,镀铜后增重2倍左右,镀铜后仍然存在石墨烯团聚现象。利用镀铜石墨烯制备铝基复合材料,避免了石墨烯与铝发生界面反应生成Al4C3。复合材料主要由铝相组成,加体积分数为5%的石墨烯时生成少量Cu Al2,在加体积分数为10%的石墨烯时,铝晶粒细化。随着镀铜石墨烯加入量增加,复合材料致密度下降,导电性能有一定改善,导热性能显著提高,硬度显著增大,添加体积分数为5%和10%石墨烯时其硬度较纯铝的分别提高了12%和75%。

Graphene-Cu/Al composites with 5%and 10%(volume fraction)graphene addition were prepared by the vacuum hot-press sintering process.The microstructure,hardness,thermal conductivity and electrical conductivity of the composites were tested with the optical microscope,scanning electron microscope,X-ray diffraction diffractometer,brinell hardness tester,thermal conductivity tester and four-point resistivity tester.The results show that chemical copper plating is carried on the graphene successfully by using the simple chemical copper plating method,the weight of the graphene after copper plating is almost tripled,however,graphene agglomeration occur after chemical copper plating.Composite materials are prepared with copper-plated graphene,and the formation of Al4 C3 after interfacial reaction between graphene and Al is avoided in this preparation method.The composite mainly consists ofα-Al phases,a small amount of CuAl2 phases are generated with 5%graphene added,andα-Al grains are refined with 10%graphene added.With more graphene added into composites,the density is decreased,the electrical conductivity is improved to some extent,and the thermal conductivity and the hardness improve greatly.The hardness of the composites are 12%and 75%(volume fraction)greater than that of pure aluminum as5%and 10%(volume fraction)graphene are added.