Investigating the influence of SiC and B ₄ C reinforcements on the mechanical and microstructural properties of stir-casted magnesium hybrid composites

Abstract This study based on Mg-based hybrid composites investigates the impact of silicon carbide (SiC) and boron carbide (B 4 C) reinforcements on the mechanical and microstructural properties of magnesium (Mg) hybrid composites fabricated via the novel vacuum-assisted stir casting. Three hybrid Mg composites, MC1 (Mg-2 wt% SiC-3 wt% B 4 C), MC2 (Mg-3 wt% SiC-2 wt% B 4 C), and MC3 (Mg-2.5 wt% SiC-2.5 wt% B 4 C) were fabricated to evaluate the influence of variations in reinforcement ratios on mechanical, microstructural and hardness of the composites. Results showed that magnesium composite MC2 exhibited the highest compressive strength and microhardness, which is attributed to the optimal load transfer and refined grains by SiC, whereas MC3 achieved the best ultimate tensile strength. The microstructural analysis confirmed uniformly dispersed particles without agglomeration. These findings suggest that SiC- and B 4 C-reinforced Mg hybrid composites offer enhanced strength, hardness, and wear resistance, making them suitable for high-performance applications in aerospace and automotive industries.