Experimental Investigation of Wear Behaviour and Mechanical Properties of Aluminium Hybrid Metal Matrix Composites Reinforced with SiC and Al₂O₃ Particles

Abstract

This paper presents a comprehensive experimental investigation into the mechanical properties and tribological wear behaviour of Aluminium 6061 alloy-based hybrid metal matrix composites (MMC) reinforced with silicon carbide (SiC) and aluminium oxide (Al₂O₃) particles. Composites were fabricated using the liquid metallurgy stir casting process with SiC and Al₂O₃ particle reinforcement varying from 0 to 24 wt% in 8 wt% increments. Tensile testing (ASTM E8M), Rockwell hardness measurement, and dry sliding pin-on-disc wear tests were conducted following a Taguchi L9 design of experiments with four factors applied load (10, 20, 30 N), sliding speed (1.0, 1.5, 2.0 m/s), sliding distance (500, 1000, 1500 m), and reinforcement weight percentage (8, 16, 24 wt%) at three levels each. Ultimate tensile strength increased by 62.6% (148.4 to 241.3 MPa), Rockwell hardness by 81.3% (52.3 to 94.7 HRB), and specific wear rate decreased by 65.7% with increasing reinforcement from 0 to 24 wt%. ANOVA identified applied load as the dominant tribological factor (48.3% contribution) followed by sliding speed (28.5%) and reinforcement percentage (17.6%). SEM micrographs confirm uniform particulate distribution at lower reinforcement levels and agglomeration tendency at 24 wt%. The optimal Taguchi composite composition for minimum wear rate is identified as A4 (20 wt% total reinforcement) balancing strength, hardness, and ductility.