Distinguishing Dynamic Recrystallization (DRX) in Aluminum and Single-Phase Alloys

Abstract

Dynamic recovery (DRV) during hot working occurs to a decreasing degree, with lower stacking-fault energy (SFE) in Al, Ni, Cu, gamma-Fe. With rising strain, the dislocations form dynamically stable boundaries (SIB). Between deformation bands, transition boundaries TD composed of at least 4 different Burgers vectors, develop to exceed 15 degrees (HAB), producing different texture components. In cold working, the presence of SIB-HAB or (TD-HAB) are not considered recrystallization until in annealing, HAB regions convert to mobile boundaries (free of dislocations within nuclei) in discontinuous static recrystallization dSRX. In hot working of Al and solute alloys, there is a critical strain for dSRX when straining is stopped. The TD are permanent and are athermal unlike the subgrain boundaries (SGB) that continually rearrange and change with temperature. In multi-directional straining, micro-shear bands that are also athermal form and become HAB possible giving rise to cDRX. In hot working of low SFE metals, the critical strain for discontinuous dDRX is higher than for dSRX that is only considered to have occurred after straining stopped. For same test condition, it is not logical to claim continuous cDRX has occurred because SIB-HAB are observed when quenched to inhibit dSRX at insufficient strain for dDRX.