Publication

Abstract : Friction stir processing (FSP) is an efficient solid-state process for the fabrication of surface composites. In the current research, FSP has been utilized to fabricate surface composite, which comprises AA7075 alloy as base material matrix and niobium carbide (NbC) as the reinforcement particles. The tensile strength, elongation, hardness, and wear rate of AA7075-NbC surface composite that is fabricated at various combinations of FSP process parameters (tool rotation speed, tool traverse speed, and groove width) are evaluated. Hybrid polynomial—radial basis function-based models are developed to correlate the relationship between the process parameters and the properties. Also, the optimum process parameters for maximizing hardness, strength, elongation, and wear resistance are deduced. The results indicate that the FSP process window for achieving the desirable properties in the AA7075-NbC surface composite is as follows: tool rotation speed between 860 and 900 rpm, tool traverse speed between 20 and 21.3 mm/min, and groove width of 1.1 mm and 1.18 mm for tensile strength, ductility; and tool rotation speed between 811 and 1043 rpm, tool traverse speed of 56 mm/min and 60 mm/min, and groove width of 1.4 mm for wear resistance. The betterment in mechanical and tribological properties is attributed to the homogeneous dispersion of reinforcement particles.