Investigating the mechanical and microstructural analysis of AA7075/SiC/SiO2 hybrid composite fabricated through microwave sintering techniques

In the present study, AA7075-based metal matrix composites were fabricated using the powder metallurgy technique followed by microwave sintering to investigate the influence of ceramic reinforcements on mechanical properties. Silicon carbide (SiC) was used as a single reinforcement in varying weight percentages (0–9 wt.%), and further enhancement was studied using a hybrid combination of SiC (fixed at 7 wt.%) and silicon dioxide (SiO₂) in varying amounts (0–5 wt.%). The mechanical behavior was characterized through compression strength and hardness measurements. Among the single-reinforced composites, the highest compression strength of 221 MPa and hardness of 97 Hv were achieved at 7 wt.% SiC. In the case of hybrid reinforcement, the composite containing 7 wt.% SiC + 3 wt.% SiO₂ exhibited the maximum compression strength of 302 MPa and hardness of 112 Hv, demonstrating a significant enhancement over the base alloy and the single-reinforced systems. These findings reveal that microwave sintering, combined with optimal hybrid reinforcement, is highly effective in improving the mechanical performance of aluminum matrix composites, making them suitable for advanced structural and aerospace applications.