高定向石墨/铜复合材料的制备和热物理性能

Preparation and thermophysical properties of aligned graphite flake/Cu composites

为了制备出具有优良热物理性能的石墨/铜复合材料,采用流延法将天然鳞片石墨定向排列在铜箔表面,并使用真空热压法制备具有层状结构的高定向石墨/铜复合材料。使用XRD和SEM等表征方法分析样品的微观形貌和成分,结果表明,在高温的作用下,流延所使用的溶剂充分挥发,热压后石墨仍高定向排列在相邻的两层铜箔之间,并相互搭接;部分熔化的铜在压力作用下渗透到石墨层的孔隙处,铜层之间相互贯穿。这种结构使石墨/铜复合材料具有优良的热物理性能。当石墨体积分数为20vol%~70vol%时,石墨/铜复合材料在高导热平面内热导率高达402~743 W/(m·K),抗弯强度达到126~48 MPa。深入讨论了石墨/铜复合材料的热传导机制,并建立了导热预测模型。

In order to prepare graphite/Cu composites with excellent thermodynamic properties,the natural graphite flakes were highly oriented on the surface of copper foil by tape casting method.The high-oriented graphite flake/Cu composites with layered structure were prepared by vacuum hot-pressing method.The phases and morphology of graphite flake/Cu composites were characterized by XRD and SEM.The results show that the solvent used for casting is fully volatilized after heat-treated process.The aligned graphite flakes between two copper foil layers overlap each other and partially melted copper penetrates other copper layers across the pores of the graphite layer.This structure allows the graphite/Cu composite to achieve excellent thermophysical properties.As the volume fraction of graphite is 20 vol%to 70 vol%,the thermal conductivity of the graphite flake/Cu composite increases from 402 W/(m·K)to 743 W/(m·K)in high thermal conductivity plane,while the bending strength is 126~48 MPa.The heat transfer mechanism of graphite flake/Cu composites is discussed deeply and a thermal conductivity prediction model has been established.