Aluminium hybrid metal matrix composites comprises of Al alloy embedded with multiple hard particulates to improve the wear characteristics. In this study Al 7075/Al₂O₃/B₄C hybrid composite was fabricated with 5 wt.% B₄C particles addition and 2, 4, 6, 8 and 10 wt.% of Al₂O₃ by liquid metallurgy route. The dry sliding wear behaviour of hybrid composites was investigated under various sliding parameters using a pin on disc tribometer. Numerical models were developed to predict the frictional and wear characteristics of the composites. Analysis of variance method and confirmation experiments were employed to validate the adequacy of the developed model. The composites with high particle content exhibits better wear resistance at various sliding conditions. Detailed metallurgical investigations were carried out on the on worn surface. The wear rate was severe at higher loads due to the crater formation and in addition to abrasive wear. The wear rate and coefficient of friction were optimized using desirability based multi criteria optimization technique.

Keywords: Alumina, Boron carbide, SEM, XRD, EDS, Dry sliding wear, RSM, Optimization