Mechanical and Microstructural Behavior of Aluminum Matrix Composites Reinforced with Silicon Carbide Particles

Abstract Metal matrix composites are increasingly sought after in high-performance sectors, particularly within the transportation industry, due to their superior strength-to-weight ratios and thermal stability. This study investigates the fabrication and characterization of aluminum matrix composites reinforced with silicon carbide particles using a sandwich-type manufacturing technique. The fabrication process involves alternating layers of aluminum sheets with polymer-dispersed silicon carbide particles, followed by hot compaction. Microstructural analysis confirmed effective SiC particle dispersion throughout the aluminum matrix and revealed critical interfacial phenomena, including aluminum carbide formation at matrix–reinforcement interfaces, along with localized microporosity and incomplete diffusion within interlaminar regions. These microstructural features profoundly influence the composite's mechanical response and performance characteristics. Nanoindentation testing demonstrated substantial local stiffness enhancements of up to 92.85% in SiC-reinforced zones, indicating effective particle–matrix load transfer at the microscale. However, macroscopic tensile testing revealed modest improvements in global strength, attributed to processing-induced interfacial defects that compromise bulk mechanical performance. This investigation provides insights into the relationship between processing-induced microstructural imperfections and their impact on mechanical properties. The findings highlight the potential of low-energy, solid-state processing for lightweight composites, emphasizing the need for strong interfacial bonding and minimal defects to transfer reinforcement benefits into structural performance.