Study on Microstructure and Properties of the As-Extruded GNS/7075 Composites
The microstructure evolution of the GNS(graphenenanosheets)/7075 composites before and after hot extrusion was analyzed by optical microscope and scanning electron microscope,and the tensile properties,microhardness and friction and wear properties of the composites were tested.The results show that the addition of GNS to the aluminum matrix can effectively refine the grain structure of the aluminum matrix,and the hot extrusion process can effectively eliminate the element segregation and GNS segregation at grain boundaries,which is conducive to the improvement of the microstructure of the composites.The tensile strength,elongation,and microhardness of the as-extruded 0.9％GNS/7075 composite are 379.1 MPa,13.5％,and HV174.1,respectively,which are 33.62％,181％,and 44％higher than those of the as-cast composite.The wear amount of the as-extruded composite is only 0.012 g,which is reduced by 0.013 g compared to the wear amount of the 7075 matrix(0.025 g).There are large areas of furrow like depressions and delamination on the grinding surface of the 7075 matrix,with a large number of pits.However,on the grinding surface of the as-extruded composite,there are rows of furrows of varying sizes,with significantly reduced depth and width,and scattered small and shallow adhesive pits.
7075 aluminum alloyGNSmicrostructuremechanical propertiesfriction and wear properties
万方数据
维普
