Wear and friction stir welding studies on synthesized aa7075 sicp composites

Abstract

Aluminium Matrix Composites (AMCs) used in spacecraft, newlineelectronic circuits and structural applications demand high mechanical newlineproperties, wear resistance and stability at above 1000°C temperature. newlineAluminium matrix with silicon carbide particulate reinforced composite newline(AA7075/SiCp) is found to be a good selection to meet these requirements. newlineIn the present study, AA7075/SiCp composites are fabricated by stir newlinecasting process and welded by a solid state welding technique called Friction newlineStir Welding (FSW). FSW resolves the hot tears and solidifying cracks newlineassociated with fusion welding of composites. In this study, AA7075 has been newlineused as matrix alloy material mainly due to its property changing capabilities newlineduring the optimal heat treatment or by subsequent cold working process. newlineSilicon Carbide (SiC) is used as reinforcement phase as it is newlinethermodynamically steady at 2730°C. SiC mixture is added to the molten newlinealuminium alloy specimen in various proportions such as 10%, 12.5%, 15%, newline17.5% and 20% and preheated for eliminating the moisture content existing in newlinethe reinforcement phase. Weight percentage (wt. %) of 1.5 of pure newlinemagnesium is added to the molten metal to increase the wettability of SiC newlineparticulate reinforcement with aluminium alloy matrix. AA7075/SiCp newlinecomposites are effectively fabricated at various proportions of SiC particulate newlinereinforcement.Optical and Scanning Electron Microscope (SEM) micrographs newlineshow uniform dissemination of reinforcement particles in the matrix alloy. newlineX-Ray Diffraction (XRD) patterns confirm the distribution of SiCp newlinereinforcement in AA7075 alloy material. Tests are carried out to estimate the newlinemicrohardness and macrohardness, newline newline