Influence of coarse second-phase particles and fine precipitates on microstructural refinement during severe plastic deformation by ECAP and on structural stability during annealing

Trabajo presentado en el TMS Annual Meetin, celebrado en San Antonio, TX (Estados Unidos), del 12 al 16 de marzo de 2006An Al-Mg-Si alloy in various solutionised and aged states was severely plastically deformed. Materials were subsequently annealed. Microstructural refinement and strengthening occur faster in the presence of particles. Coarse particles remain unaffected by severe deformation, and help stabilise the deformation microstructure, while fine precipitates dissolve. Microstructural refinement and strengthening depends more on solute content than on particle distributions. Solute precipitates on annealing, irrespective of the initial material state, but these particles play only a small role in stabilising deformation substructure. After significant particle and grain coarsening at high temperatures, discontinuous grain coarsening may occur. Material strength has also been examined in terms of the contributions of loosely-arranged dislocations, grain boundaries, and dispersed particles and the importance of each contribution deduced.Peer reviewe