Effect of Volume Percentage of Reinforcement on the Microstructure and Mechanical Properties of an Al6061-T6/SiC Surface Composite Fabricated Through Friction Stir Processing

In this research, aluminium metal matrix composites (AMMCs) have been manufactured through friction stir processing (FSP) by reinforcing nano-sized SiC particles in an Al6061-T6 alloy. The consequences of the volume percentage of reinforced SiC particles on mechanical properties and microstructural features were analyzed for the developed AMMCs. Microstructural evaluation of a cross-section of a friction stir processed (FSPed) sample has been conducted through Electron backscatter diffraction (EBSD) Energy dispersive spectroscopy (EDS) and a scanning electron microscope (SEM) technique. Microhardness tests were conducted athwart the cross section of FSPed specimen to obtain microhardness feature. A tensile test of FSPed samples has been conducted on a universal testing machine (UTM). Homogeneous distributions of SiC particles were found in the stir zone without any consolidation of particles. The size of the reinforcement particles was decreased slightly by increasing the volume fraction. It has been found that increasing the volume fraction of SiC particles, enhance the tensile strength and microhardness, but decreases the ductility of the aluminium. The maximum ultimate tensile strength (UTS) and microhardness were obtained as 390 MPa and 150.71 HV, respectively, at 12% volume percentage of reinforcement particles. UTS and microhardness of the FSPed Al/SiC have been improved by 38.29% and 59.48% respectively as compared to Al6061-T6. The brittle nature of the FSPed Al/SiC has increased due to a rise in the volume fraction of nanosized SiC particles, which causes a decrease in ductility.