Achieving dispersed fine soft Bi particles and grain refinement in a hypermonotectic Al-Bi alloy by severe plastic deformation and annealing

摘要

The present work revealed that equal-channel angular pressing (ECAP) deformation combined with appropriate annealing could represent as an efficient route to modify immiscible as-cast microstructure of a monotectic Al-8Bi alloy by a complete redistribution of immiscible Bi particles and grain refinement of alloy matrix. Especially, we found that the mean size of Bi particles in the 4-pass ECAPed Al-8Bi sample decreases after annealing at 200 degrees C for 8 h, due to inverse coarsening driven by the reduction of elastic energy and interfacial energy induced by morphology change and spatial distribution of Bi particles. (C) 2018 Acta Materialia Inc. Published by Elsevier ltd. All rights reserved.