Controlled precipitation by thermal engineered laser shock peening and its effect on dislocation pinning: Multiscale dislocation dynamics simulation and experiments

This study quantitatively investigates a novel surface processing technique, thermal engineered laser shock peening (LSP), which takes advantage of dynamic precipitation, dynamic strain aging and static aging effects to obtain the optimal microstructures for the extended fatigue life of metallic components. The mechanism of thermal engineered LSP was discussed in terms of the dislocation pinning effect and the precipitation kinetics. Multiscale discrete dislocation dynamic simulation was carried out to study the pinning strength affected by precipitate parameters, such as volume percentages and sizes. The mechanism of mechanical properties enhancement, such as surface hardness and cyclic stability of surface strength, were investigated by experiments and compared with the simulation results. (c) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.