Experimental investigation of the microstructural and wear behaviours of silicon carbide and boron nitride-reinforced AZ91D magnesium matrix hybrid composites

Abstract

This study aimed to fabricate hybrid metal matrix composites of AZ91D magnesium reinforced with varying various weight percentages of SiC and constant weight percentages of BN particles through the stir-squeeze casting method. The influence of the particle ratio on the microstructure and wear behaviour of the composites was studied. The dispersion patterns of particles within the matrix and the interactions between the alloy and the particles were thoroughly investigated using a variety of techniques, including optical microscopy, SEM, EPMA, and EDS.XRD analysis of the AZ91D/SiC/BN hybrid composite revealed a significant volume proportion of the strong Mg17Al12 phase. The synthesized magnesium hybrid composites (AZ91D/9%SiC/3%BN) experienced a volume loss reduction of up to 36.16% under a maximum load of 30 N and a maximum speed of 1 m/s when compared with the monolithic material AZ91D. The results of these analyses demonstrated that the resulting composites exhibited an even dispersion of particles, superior grain structure, and strong interfacial bonding between the AZ91 alloy and the reinforcing particles. The newly developed magnesium hybrid composites have better wear performance than monolithic AZ91D alloys. These findings highlight the enhanced wear resistance of the fabricated composites for antiwear applications.