Abstract
Boron carbide particulate reinforced cryomilled aluminum alloy composites produced through various consolidation methods exhibit significant differences in microstructural and mechanical performance. The microstructural differences such as grain sizes and their distribution were characterized in detail, and the relationships between grain size and work hardening rate and strain rate sensitivity were studied in the characteristic length scale 150-2000 nm. The role of geometrically necessary dislocations (e.g., due to thermal expansion mismatch strain) on the mechanical behavior was investigated for select microstructures.