Preparation,Microstructure And Properties Of Graphene-Reinforced Copper Matrix Composites

Graphene is an ideal reinforcing phase for Cu matrix composites due to its superior mechanical properties,excellent electrical and thermal properties.In this paper,reduced graphene oxide(RGO)-enhanced Cu matrix nanocomposites specimens were prepared by molecular-level mixing,and RGO/Cu nanocomposite samples were prepared by discharge plasma sintering(SPS).The microstructure,physical and mechanical properties?friction and wear properties were studiedThe microstructure of composite materials before and after thermal reduction under the optimal conditions was analyzed,and it was confirmed that the rod-like Cu O particles coated by GO were reduced to the spherical Cu particles coated on the RGO surface with dense distribution.Raman spectrum analysis confirmed that functional groups on GO surface were removed and graphene structure was restored in the reduction process.Fourier infrared spectroscopy(FTIR)was used to determine the coordination reaction between GO surface functional groups and Cu~+.Samples of RGO/Cu nanocomposites were prepared by molecular mixing method and SPS sintering technology at different solution reaction temperatures,and the effects of solution reaction temperature on the microstructure and properties of the nanocomposites were studied.Results show that when the reaction temperature is80?solution and the microstructure of the composite material to achieve the best appearance,Cu plating covered the whole of RGO,and Cu continuous dense grain distribution.Moreover,RGO/Cu nanocomposite samples have the best comprehensive properties,and their density,hardness,thermal conductivity and electrical conductivity all reach the maximum.Reaction temperature at 80?solution,using molecular hybrid method and SPS sintering technique in different solution PH RGO/Cu nanocomposite was prepared,and the solution PH value impact on the microstructure and properties of composite materials.The results showed that at PH 10,the microstructure of the composites reached the optimal morphology,and also had the best comprehensive properties.At this time,the density,hardness,electrical conductivity and thermal conductivity of the composites reached 0.955,111HBS,90.5%IACS and 370 W/m·k,respectively.Therefore,the optimal PH value of RGO/Cu nanocomposite prepared by molecular level hybrid method is 10.The properties of RGO/Cu nanocomposites prepared with different contents of RGO were tested.The test results showed that the density,thermal conductivity and electrical conductivity of the composites all decreased with the increase of RGO content.However,the hardness,tensile strength and bending strength of the composite first increases,then it decreases.Through the friction and wear experiments of composites sliding speed and content of RGO influence on friction and wear performance,the results show that with the increase of sliding velocity,increase in the number of gas into the ring and between samples,this aspect can make the gas buoyancy increase,lead to reduce the pressure on the sample of the on the other hand,the increase of the gas can produce gas lubrication on the wear surface,led to the decrease of the friction coefficient and wear rate.Therefore,with the increase of sliding speed,the wear resistance of the composite increases.With the increase of RGO content,the interface between RGO and copper in the composite increases,leading to the decrease of its strength,so the friction coefficient and wear rate increase.Therefore,with the increase of RGO content,the wear resistance of the composite decreases.