Processing, Characterization, and Properties of α-Al₂O₃-AA2900 Composites for Aerospace Brake Pad Applications

Replacing high-strength frictional materials with lightweight composite alternatives is currently a global challenge for researchers. In this work, aluminum alloy (AA2900)-based metal-matrix composites reinforced with 6 wt.% α-alumina were fabricated then subjected to T6 heat treatment followed by case hardening. The resulting composite samples exhibited improved hardness, strength behavior, and stress–strain behavior along with good ductility and formability when microwave sintered. Good microstructural bonding was observed for all samples, which can be attributed to the finer α-Al₂O₃ particulates used as the reinforcement and the microwave sintering process. The mechanical and wear properties of the composites were compared with existing aerospace brake pad material. Data for wear characteristics versus the number of landings for the existing brake pad material were considered as the benchmark data, and the feasibility of replacing it with the developed composites was evaluated.