Research On Preparation And Microstructure And Property Of Graphene Nanoplatelets Reinforced Aluminum Matrix Composites

Due to its excellent mechanical properties,graphene is considered as an ideal reinforcement for metal matrix composites.The preparation of graphene-reinforced aluminum matrix composites by adding graphene into aluminum alloy is a new development direction of aluminum matrix composites.At present,there are many problems to be solved in the preparation of graphene-reinforced aluminum matrix composites.At the same time,the current method for the preparation of graphene-reinforced aluminum matrix composites is not suitable for large-scale production and application due to its complex process and high cost.Therefore,it is necessary to develop a low cost,simple process,suitable for industrial applications of the preparation method.In this paper,Graphene nanoplatelets(GNPs)were used as the reinforcing body,and ZL101 alloy was used as the matrix to prepare GNPs reinforced aluminum matrix composites by ball grinding and semi-solid electromagnetic stirring.The mixed powder was characterized and analyzed by SEM and XRD.The microstructure of the composites was characterized and analyzed by means of metallographic microscope,scanning electron microscope,transmission electron microscope and X-ray diffractometer.The density,densification and mechanical properties of the composites were tested and analyzed.The main research results are as follows:After ball milling,the powder was flaky,the GNPs and ZL101 alloy powder were well mixed,and the GNPs and ZL101 alloy powder were well combined.The GNPs reinforced aluminum matrix composites can be successfully prepared by semisolid electromagnetic stirring.The GNPs is flaky and strip,evenly distributed in the composites and well combined with the aluminum matrix to maintain the structural integrity.The content of GNPs has great influence on the microstructure of the composites.The average grain size of the composites decreased first and then increased with the increase of GNPs content.When the GNPs content was 0.6wt%,the average grain size of the composites was the smallest,21.6?m.The content of GNPs will affect the mechanical properties of the composites.The hardness,tensile strength and elongation of the composites increased first and then decreased with the increase of graphene content.When the content of GNPs was 0.6wt%,the mechanical properties of the composites were the best,with the highest hardness,tensile strength and elongation of 91.9HV,180.2MPa and 5.5%,respectively,which were 30.7%,25.3% and 244% higher than that of the matrix.