Fabrication and metallurgical characterization of hybrid al matrix composites reinforced with SiC and Al2O3 using powder metallurgy

Abstract Aluminum matrix composites (AMCs) have emerged as advanced engineering materials due to their superior mechanical and tribological performance compared to conventional aluminum alloys. In this study, hybrid AMCs reinforced with silicon carbide (SiC) and aluminum oxide (Al₂O₃) are fabricated through the powder metallurgy (PM) route. Taguchi L16 orthogonal array was employed to design experiments to investigate the effects of reinforcement weight% (wt%), milling speed, and sintering temperature. Microstructural investigations using SEM and XRD confirmed uniform dispersion of reinforcements under optimized conditions, the absence of impurities, and the formation of new phases within the aluminium matrix. ANOVA identified SiC % as the most influential parameter. A multi-response optimization based on Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) obtained superior metallurgical properties with highest hardness (72 HV) and the lowest wear rate (3.6 × 10⁻³ mm³/N·m) at 12 wt% SiC, 7 wt% Al₂O₃, 170 rpm milling speed, and 600 °C sintering temperature. This study demonstrates the potential of PM methods for producing hybrid AMCs with enhanced mechanical and tribological properties, highlighting their suitability for engineering applications such as in automotives where strength, hardness, and wear resistance are critical.