Preparation And Study On Properties Of Copper Matrix Composites Reinforced By Nano-materials

Nano alumina dispersion strengthened copper matrix composites and carbon nano phase(carbon nanotubes,graphene)reinforced copper matrix composites have have great potential application in electrical engineering,military industry,mechani-cal manufacture and so on,they not only have excellent electrical and thermalcon-ductivity,and also have high hardness and strength.But these nano particles tend to reunite during the fabrication processing due to the poor affinity to copper matrix.And the current investigation of nano phase reinforced copper matrix composites is limited by the technology of large-scale preparation and the cost.In this study,alu-mina copper composite powders and carbon nanotubes copper composite powders were prepared by solution combustion method,graphene copper composite powders were prepared by electrostatic-assisted solution mixing using combusted porous sheet-like Cu2O.The composites were prepared by powder metallurgy.The effects of three kinds of nano materials on the microstructure,microhardness and conductivity were studied.(1)Alumina strengthened copper matrix composites were prepared by solution combustion-reduction-sintering process.Scanning electron microscopy showed that the alumina was uniformly dispersed in the copper matrix.And the copper grains are refined with the increase of the alumina content.The results show that,1000℃ and 550Mpa are the best sintering temperature and molding pressure respectively for the composites.When the content of Al2O3 was 0.5wt%,the hardness of the composite was increased to 137 HV,and the high conductivity(90%IACS)was maintained.(2)Graphene copper composite powders were prepared by electrostatic-assisted solution mixing using combusted porous sheet-like Cu2O.The composites were pre-pared by powder metallurgy.The results show that the reduced graphite oxide is uni-formly dispersed in the copper matrix,which is obviously superior to that of the copper matrix composites prepared by PVP modified graphene.When the content of RGO was 1wt%,the microhardness of the composites increased by 26.3%,and the conductivity was still as high as 90%IACS.After the addition of alumina,the hardness increased significantly,which was 4 times higher than that of pure copper.(3)CNTs/Cu composites were fabricated by solution combustion method and electrostatic-assisted solution mixing method using combusted porous sheet-like Cu2O,respectively.For the solution mixing method,due to the lack of effective binding,carbon nanotubes and copper matrix have been separated from each other after sintering,while in the solution combustion method,good interface bonding was obtained,and the performance of the material is better than that of solution mixing method.