添加铜网对片层石墨/Al复合材料热物理性能的影响

Effects of Cu mesh on thermal conductivity and mechanical properties of graphite flakes/Al composites

使用盐浴法对片层石墨(GFs)进行表面镀Si处理,采用真空热压法制备片层石墨/Al复合材料(Si-GFs/Al)。向Si-GFs/Al复合材料中添加10vol%的铜网,研究了铜网对Si-GFs/Al复合材料热导率和力学性能的影响。使用SEM、聚焦离子束(FIB)和TEM对Si-GFs/Al复合材料的微观结构和微观界面进行表征,并分析了复合材料的断裂机制。结果表明,添加铜网使Si-GFs/Al复合材料内部出现了高聚集定向GFs带,形成高导热通道。当GFs体积分数为30vol%~40vol%时,Si-GFs/Al复合材料的热导率提升了约20%,弯曲强度提升了40%以上。当GFs体积分数为40vol%时,Si-GFs/Al复合材料热导率和弯曲强度同时达到一个优值,分别为512W/(m·K)和127MPa。

The surface of graphite flakes(GFs)was coated with Si by salt bath method,and the graphite flakes/Al composites(Si-GFs/Al)were prepared by vacuum hot pressing method.10vol%Cu mesh was added to Si-GFs/Al composites,and the effects of Cu mesh on thermal conductivity and mechanical properties were studied.The microstructure and micro interface of Si-GFs/Al composites were characterized by SEM,focusing ion beam(FIB)and TEM.The fracture mechanism of the composites was analyzed.The results show that highly clustered GFs bands have been built in the Si-GFs/Al composites after Cu mesh added.When the GFs volume fraction is 30vol%~40vol%,the thermal conductivity of Si-GFs/Al composites increases by about 20%,and the bending strength increases by more than 40%.The thermal conductivity and bending strength of Si-GFs/Al composites with 40vol%GFs both reach a satisfactory value,which are 512W/(m·K)and 127MPa,respectively.