Influence of hybrid pin profile on microstructural and mechanical properties of Al/SiC graded composites produced by friction stir processing

Abstract

Friction stir processing (FSP) was employed to fabricate a surface graded composite by embedding SiC reinforcement particles in an AA6082-T6 matrix. Conical blind holes were drilled on the surface of the plate with varying inter-hole distances. The processing was performed with the different number of passes by keeping rotational and traverse speed constant. A new hybrid tool with a combination of conventional conical threaded tool and the triangular cross-sectioned tool was used in processing. The microstructural features of the processed samples were examined by a 3D microscope and scanning electron microscope (SEM). Mechanical properties such as microhardness, tensile strength was thoroughly evaluated. It is reported that the number of passes played an essential role in the distribution of reinforcement particles and grain refinement. The hardness value improved by applying multiple passes. The fractured tensile samples showed ductile failure. The sample treated with double passes gave better results with the homogenous distribution of reinforcement particles compared to samples processed with a single pass.