Study On Mechanical Properties And Thermal Conductivity Of Surface-modified Graphite Copper/aluminum

Because of the characteristics of high thermal conductivity,low thermal expansion coefficient and low density,flake graphite has been used as the reinforcement of metal matrix composites.At present,the most concerned electronic packaging materials are graphite/aluminum composite materials and graphite/copper composite materials,which are affected by the extreme working environment.In order to ensure the thermal conductivity of the composite materials,the process of optimal friction factor,wear amount and mechanical performance is studied.In this paper,the surface of graphite paper was modified by chemical oxidation to improve the interfacial bonding ability of graphite paper and copper foil,and graphite paper/copper composite material with thermal conductivity of about 950 W/(m·K)was prepared.Use salt bath method and the electroless coating method was carried out on the flake graphite surface coating modification,set three groups,strengthen the body is not coated graphite respectively,plating silica ink,and copper coated graphite surface characterization results,graphite coating processing,can significantly increase the flexural performance of composite materials,reduce the amount of wear and tear,improve the interface bonding ability,the main researching content is as follows:(1)changes of flexural property,friction factor,wear amount and thermal conductivity of graphite composites with different volume fractions.(2)change of microstructure and improvement of interfacial bonding ability in graphite composites with different coatings.(3)compare the advantages and disadvantages of graphite/aluminum composites with different coatings,analyze the microstructure and material composition,and explore the influence of internal graphite surface modification on graphite/aluminum composites.As a result,it was found that the friction factor of the graphite aluminum XY plane is smaller than that of the Z plane,and the wear amount of the XY plane is larger than that of the Z plane.The thermal conductivity increases as the volume fraction of graphite increases.The friction factor of the copper-coated graphite / aluminum composite is 0.18,the friction factor of the silicon-coated graphite / aluminum composite is 0.2,and the friction factor of the uncoated graphite / aluminum composite is 0.16.