Friction stir processed Al 7075 matrix composites with addition of SiC coated graphene nanoplatelets

Friction Stir Processing (FSP) is a surface modification technique that has been commonly used while preparing surface composites. Through FSP, the surface properties such as strength, hardness, wear, and corrosion resistance could be enhanced by adding discontinuous reinforcements in the base alloy. The present experimental investigation involves nano reinforcements i.e graphene nanoplatelets (GNP) and SiC coated GNP was reinforced into Al 7075 and fabricated nano surface composite via Friction stir processing (FSP). A nano SiC granular and layered coating over GNP was obtained from FESEM studies. The Surface morphology, tensile strength, microhardness, and wear studies were explored. The hardness and ultimate tensile strength values of FSP'ed Al 7075, GNP, and SiC coated GNP in Al 7075 were 96.2, 128.4, 139.3 HV, and 344.8, 383.2, and 417.5 N/mm2 respectively. The hardness and ultimate tensile strength significantly increased by 44% and 21%. In similar lines, the specific wear rate also decreased 80% compared to other samples due to its lubricant property. X-RD analysis affirms the existence of Al, SiC, GNP phases that match with the lattice planes. Microscopic studies revealed the presence of SiC particles on GNP as a form of coating and also dispersed uniformly in Al 7075 composites. © 2022