Experimental Investigations on Microstructure, Mechanical Behavior and Tribological analysis of AA5154/SiC Composites by Stir Casting

Aluminum metal matrix composites (MMCs) exhibit promising mechanical properties that are potential materials for the aeronautical and automotive industries. In this study, aluminum-magnesium base alloy i.e. 5154 based composites reinforced with silicon carbide (SiC) particles were fabricated by the stir casting process. The mechanical properties such as tensile strength, impact strength, and micro-hardness were evaluated. The microstructural analysis was studied using field emission scanning electron microscopy and X-ray diffraction analysis. With uniform dispersion and good interfacial bonding between the aluminum and silicon carbide, the mechanical properties were found to be enhanced significantly. The 15wt% SiC reinforced composites exhibited a maximum enhancement of 37 % in the hardness, 35 % in the tensile strength. The impact strength was found to be reduced by a maximum of 37 % when compared with the base aluminum alloy showing the loss in ductility. Furthermore, the sliding wear behavior of the SiC reinforced composites was also studied. The wear rate during the test was found to be decreased with sliding distance whereas an increase in the applied load resulted in a higher wear rate. At 2000 m of sliding distance, the wear rate of 15wt% SiC composite was reduced by 51 % as compared to base alloy at an applied load 10 N whereas, at 30 N of applied load, the wear rate was reduced by 66 %. A reduction in the volumetric wear loss of the composites was observed as compared to the base alloy indicating an enhancement in the wear resistance of the composites.