Characterization of Aluminum Matrix Composites Reinforced with Al2O3, SiC and Graphene Fabricated by Spark Plasma Sintering

In this study, aluminum matrix composites reinforced with Al2O3 and SiC nanoparticles, and graphene nanoplatelets produced by spark plasma sintering (SPS) were studied. The microstructural and mechanical properties of the composites were evaluated by changing the amounts of the reinforcing materials. The SEM images showed that the reinforcing particles were more distributed in the grain boundary regions. According to the results, the addition of alumina and SiC to the matrix caused an increase in the composite density whereas the composite density decreased by adding graphene nanoplatelets. The highest relative density of 96.3% was obtained for the composite containing 2 wt.% Al2O3. The presence of the reinforcing particles increased the hardness of all the samples compared to the pure aluminum (39 HV). The composite containing 1 wt.% Al2O3, 0.7 wt.% SiC, and 0.3 wt.% graphene showed the highest hardness of 79 HV. Moreover, the plastic deformation of the specimens decreased and the slope of the plastic region increased by adding the reinforcing particles to the matrix.