Research On Densification Process And Electrical Contact Properties Of RGO/Cu Composites

In this paper,the percolation threshold of the lamellar second ph ase in the copper-based electrical contact material was calculated based on the effective medium theory.The graphene-optimized copper-based electrical contact material was prepared by powder metallurgy method.The densification process of the material was studied.The influence of isostatic pressing,sintering,re-pressing and annealing process on the microstructure and properties of copper-based electrical contact materials were studied.The influence of the addition amount of graphene on the properties of the material was also studied.Various stages of powder compacting process were studied.The compact process of graphene optimized copper-based materials was consistent with the general law of pressing.The density sintered samples increase with the pres sure at first and then decrease.GO content had no significant effect on the pressure after initial pressure.The second phase particles,which are annularly distributed across the grain boundaries,are observed in the annealed and reconstituted samples.Th e size of the ring is between 20 and 30 μm.In the pure copper + 0.2wt% GO sample,GO particles with a particle size of about 1μm was observed.The distribution of carbon in the alloy sample was uniform and no GO particles were observed.A hardness of HV77.8 was obtained by annealing and re-burning,and 0.2% by weight of GO was added to the sample,and the hardness was up to HV130.1 by extrusion rolling.When the addition amount of GO is more than 0.002wt%,the tensile strength of the material is improved greatly,reaching up to 298 MPa.When the addition amount is 0.002wt%,the conductivity reaches the maximum value of 94.5% IACS.The contact resistance of the alloy material with the equivalent amount of GO was about 600mΩ after 5000 arc ablation tests,which was significantly lower than that of the pure alloy under the same conditions.Where the width and intensity of the crack is less than that of the pure alloy material under t he same conditions.