Research Of Graphene-reinforced Silver Matrix Composites

The few-layer graphene nanoplates(FGNP),graphene-Ag nanoparticles composites(GNP-Ag)and reduced grphene oxide(RGO)were used to prepare the FGNP/Ag composites,the GNP-Ag/Ag composites and the RGO/Ag composites by powders metallurgy technology respectively.The microstructure were characterized by scanning electron microscope(SEM),transmission electron microscope(TEM)and Raman spectroscope(Raman).The density,hardness,electrical conductivity and thermal conductivity were measured.The following conclusions can be obtained from above investigation.(1)The FGNP addition can effective improve the properties of the FGNP/Ag composites prepared by 100nm Ag powders.In comparison with pure Ag,only adding O.1wt%FGNP to 100nm Ag matrix,the hardness and the thermal conductivity of the composites were increased by 53%and 28%respectively,while its electrical conductivity had little change.The FGNP addition can improve the properties of the FGNP/Ag compositse prepared by 800nm Ag powders.In comparison with pure Ag,only adding 0.1 wt%FGNP to 800nm Ag matrix,the hardness and the thermal conductivity of the composites were increased by 22%and 15%respectively,while its electrical conductivity had little change.Both the hardness and electrical conductivity of the composites reduced with the increase of the FGNP content.(2)A small amount of GNP-Ag into 100nm Ag powders can improve the properties of GNP-Ag/Ag composites,when the graphene content of the composites was 0.1 wt%,its hardness was increased by 14.4%,while its electrical conductivity had little change simultaneously,but the increased graphene content reduced the hardness and electrical conducitvity of the composites.Due to the seriously GNP-Ag aggregation and curliness in 800 Silver matrix,it had no strengthening effect,the increased graphene content reduced the hardness of the GNP-Ag/Ag composites,but had little effect on the electrical conductivity for the GNP-Ag composites.(3)The high the sintering temperature promoted the GO reduction.The ratio of ID/IG of was above 1 for the RGO/Ag composites,suggested that the GO was reduced remarkably.With increase of the sintering temperature,the relative density and hardness of RGO/Ag composites reduced,while the electrical conductivity increased.