Microstructural features influencing the strength of Trimodal Aluminum Metal-Matrix-Composites

Trimodal Al Metal-Matrix-Composites (MMCs), consisting of a nanocrystalline Al phase (NC-Al), B4C reinforcement particles, and a coarse-grain Al phase (CG-Al), were successfully fabricated on both lab and commercial scales. Multi-scale microstructural features contributing to the exceptional high strength of Trimodal Al MMCs were examined via comprehensive microstructural and spectroscopic analysis. Size and distribution of nanocrystalline Al grains, B4C particles, coarse-grain Al, and uniformity in distribution were examined and quantified. Other features such as dispersoids with and without nitrogen (e.g., Al2O3, Al4C3), dislocation density, and interfacial characteristics were also examined with due respect for their contributions to the strength of Trimodal Al MMCs.