Experimental investigations of AA6061/Al2O3/WC/SiC hybrid metal matrix composite fabricated by two step stir casting

Abstract

Hybrid metal matrix composites have emerged as an epicentre of material research due to their vast applications and a wide array of reinforcement combinations. In this experiment, two-step stir casting method had been used to fabricate hybrid aluminium 6061 metal matrix composites. The micro-structural and mechanical evaluation (density measurement, impact, tensile, hardness, and flexural) of the fabricated aluminium (AA6061) hybrid metal matrix composite had been performed. The reinforcements used were Al2O3 (3 wt.%), RHA (2 wt.%), WC (2 wt.%), and SiC (5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%). The mechanical properties had been found to improve with increasing wt.% of SiC. The maximum experimental density (2999.2 Kg/m3), impact energy (6 J), tensile strength (130.15 N/mm2), hardness (35 HRA), and flexural load (6720 N) had been obtained with 20 wt.% SiC reinforcement. The presence of reinforcements (Al2O3, RHA, WC, SiC) and their uniform distribution in the Al6061 matrix was confirmed by micro-structural analysis. Other surface morphological information like agglomeration of less soluble alumina and presence of dendrite structures at higher SiC concentration were also revealed. Further, the observations from this investigation have been compared with already existing literature. In conclusion, prospects for future research have also been explored.