Effect of Graphene Nanoplatelets on Microstructure and Mechanical Properties of AlSi10Mg Nanocomposites Produced by Hot Extrusion

In this research, AlSi10Mg composites reinforced with graphene nanoplatelets (GNPs) were fabricated in order to study the effect of GNPs on microstructure and mechanical properties of the AlSi10Mg alloy. The composites were produced by a wet mixing method followed by two-step hot consolidation (hot compaction then hot extrusion) at 673 K (400°C). The weight percentages of GNPs were 0.5 and 1 wt.% with respect to the AlSi10Mg alloy. Tensile and Vickers hardness tests at room temperature were performed to evaluate the effect of GNPs on mechanical properties of asfabricated composite. The outcomes show that the high quantity of GNPs (>0.5 wt.%) deteriorates the mechanical properties of AlSi10Mg composite due to the agglomeration of GNPs and, as a consequence, introduction of internal porosity in the composite. However, it is found that relatively low fraction of GNPs can uniformly be dispersed in the Al alloy matrix through the wet mixing method. The hardness and tensile results demonstrated that the mechanical properties improve slightly through the addition of 0.5 wt.% of GNPs, while 1.0 wt.% GNPs addition did not lead to improved performance owing to overwhelming effects of porosity.