Influence of tool rotation speed on mechanical and microstructural characteristics of friction stir weld 7075 aluminum alloy reinforced with graphene nano platelets

Abstract. The growing demand for lightweight, durable materials within the aerospace industry has motivated researchers to develop composites exhibiting exceptional mechanical properties, thereby enabling a more economical and environment-friendly transformation. Carbonaceous reinforcement is increasingly prioritized due to its exceptional properties in modifying and enhancing the mechanical, microstructure, and tribological properties. In the present research, the nanocomposite of AA7075 aluminum alloy reinforced with graphene nanoplatelets (GNPs) has been developed through friction stir welding (FSW) technique. Obtained the significant process parameter of tool rotation speed 800 rpm, traverse speed 20 mm/min, and tilt angle 2º respectively. Microstructure in nugget zone exhibits fine and uniform grains. It results in significant enhancement of ultimate tensile strength (UTS) 821 MPa and yield strength (YS) 389 MPa. Further, higher hardness of 141 HV is reported in the nugget zone. Moreover, the joint is fractured at nugget zone and it represents the weakest part of the weld joint.