Fabrication And Properties Of Intercalated Graphite Fibre Reinforced Copper Matrix Composites

The addition of graphite fibers as reinforcement phases to copper matrix can produce composite materials,which improves their strength and heat resistance.Such new materials demonstrate superior mechanical properties and thermal conductivity as well as good resistance to friction and wear,bringing them broad application prospects.In this study,firstly,various molar ratios of CuCl₂ to graphite fibers and the reaction time was investigated.The stage structure of the formed intercalated compounds?GICs?on the surface of the graphite fiber was examined by XRD.The optimal intercalation process for the surface modification of the graphite fiber was carried out.Then the GICs modified graphite fiber reinforced copper matrix composites were prepared by a powder metallurgy hot-pressing sintering method.The effects of different volume fractions of intercalated graphite fibers on the mechanical and electrical properties of the composites were studied.Finally,the friction and wear test for the produced composites were carried out by a high-speed reciprocating friction and wear tester,and their friction and wear mechanism of the composites were discussed in detail.The results show that the prepared GICs by the molted CuCl₂ can effectively modify the surface of graphite fibers and thus improves the wettability between graphite fibers and copper matrix.The molar ratio of the reactant CuCl₂ to the graphite fiber and the reaction time are the main factors,affecting the surface microstructure of the graphite fiber.The fabrication process can control the product stage level and the amounts of copper chloride in the GICs.The solvent-wet mixing method,followed by a ball-milling method are used as the mixed powder process,which effectively disperse the graphite fibers into copper matrix.The density and electrical conductivity of the composites decrease with the increase of the intercalation treated graphite fiber contents.Combined with the hardness of the composites,the optimum combination of hardness and electrical conductivity is achieved when the intercalated graphite fibers was 7.5 vol%.In the friction and wear test,graphite fibers were found to play a very good self-lubricating effect.When the volume fraction of graphite fibers is less than 10%,the variations of the coefficient of friction was unstable.The uniformity of distribution for graphite fibers on the friction surface is improved.The wear mechanisms of intercalated graphite fiber reinforced copper matrix composites are mainly adhesive wear and abrasive wear.In addition,peeling and oxidation wear are found.However,when the load was increased from 5N to 7N,the wear mechanism of the composite material did not change.In this case,the graphite fiber had little effect on further reduction of wear.