Nanoparticle-reinforced Aluminium Matrix Hybrid Composites: Processing and Characterization

In the pursuit of high-performance materials for demanding applications, the development of hybrid composites has emerged as a breakthrough solution. In the present work, A356 matrix hybrid nanocomposites reinforced with boron carbide (B4C) (1, 2, 3, 4, and 5 wt.%) and zirconium dioxide (ZrO2) (1 wt.% constant) were produced by the two-step stir casting technique assisted by ultrasonic vibrations. Microstructure, mechanical characteristics, and tribological behaviour of A356–B4C–ZrO₂ hybrid composites were investigated. The impact of T6 heat treatment on the mechanical characteristics of the prepared composites was also examined. The microhardness, yield strength, and ultimate tensile strength of the hybrid composites showed improvements of 35%, 66%, and 60%, respectively, compared to the A356 matrix. The fracture morphology of the hybrid nanocomposites was analyzed using scanning electron microscopy. The even dispersion of nanoparticles achieved through mechanical stirring and ultrasonic vibration assistance, along with microstructural changes such as precipitation hardening and spheroidization of silicon particles due to thermal treatment, significantly lowered the wear rate and friction coefficient.