Microstructural and Wear Characteristics of Friction Stir Processed Al-7075/SiC Reinforced Aluminium Composite

Abstract

Abstract Friction stir processing (FSP), a solid-state surface modification technique, derived from friction stir welding (FSW) process has been evolved as an efficient energy processing technique to fabricate aluminium matrix composites (AMCs). In the present investigation, FSP was used to fabricate 7075-T651 aluminium alloy surface composites using micro sized silicon carbide (SiC) particles as reinforcement. Since Aluminium 7075 alloy has a vast applications in the automotive and aerospace and having the highest strength among all commercial Al-alloys, has been selected for the matrix phase. AMCs were fabricated at different combinations of rotational speed and welding speed. The different combinations were tested for single and triple pass. The fabricated surface composites were examined for microstructure using SEM equipped with EDXS. The micro-hardness was measured and sliding wear behaviour was also evaluated using a pin on disc apparatus. It was observed that the average hardness of the FSP zone composite was 1.65-2.15 times higher than that of parent metal (78VHN). Wear rate along with the frictional force characteristics were found to be promising than the parent metal.