Strengthening mechanisms in cryomilled ultrafine-grained aluminum alloy at quasi-static and dynamic rates of loading

To achieve lightweight and high-strength materials, Al alloy has been cryomilled and processed to obtain refined microstructures. The microstructure and strengthening mechanisms of the resulting ultrafine-grained material are investigated in this work. Contributions from the several mechanisms (boundary strengthening, solid solution strengthening, precipitate strengthening and dislocation strengthening) are discussed and estimated using simplified models. Comparison with experimental data suggests some directions for materials design. (C) 2008 Acta Mateialia Inc. Published by Elsevier Ltd. All rights reserved.