Recrystallization behavior and mechanical properties of AZ31B alloy during the hot-rolling process

Abstract

In this work, microstructural characteristics, dynamic recrystallization and mechanical properties of the hot-rolled AZ31B were investigated. The results indicated that the different mechanisms of recrystallization are responsible for the microstructural evolution during the rolling deformation. It was found, as for the specimens with the rolling reduction of 30%, large number of twins are formed within the deformed matrix and the recrystallized grains are usually formed nearby the twins. This indicated that the mechanism of the twin-induced nucleation mainly dominates the recrystallization process of the specimens with the 30% reduction. As for the specimens with the rolling reduction of 75%, the recrystallized grains are nucleated on the bulged boundaries or within the deformed grains. This indicates that the mechanisms of the stress-induced grain boundary migration (SIBM) and the sub-grain growth mainly dominate the recrystallization process of the specimens with the reduction of 75%. The recrystallization process contributes to the grain refinement and to the improvement of mechanical properties of alloys. Eventually, the specimens with the rolling reduction of 75% obtain an excellent strength-ductility balance. The results of this work not only elaborate underlying knowledge on the correlation relationship between the recrystallization mechanisms and the mechanical properties, but provide an effective approach to optimize the microstructure-mechanical properties of alloys.