Recrystallization mechanisms and microstructure development in emerging metallic materials: A review

This review is devoted to the understanding of the recrystallization mechanisms and its role in the control of the microstructure in emerging metallic materials. Recrystallization is a very pervasive transformation phenomenon that is considered to be very important in efficient microstructure designs. Currently, there is hardly any work which has attempted to present a concise and systematic review of the recrystallization in emerging materials with a view to reconcile its manifestations with trends established from recrystallization studies in traditional alloys. This review aims to address this by first reviewing the fundamental and nascent recrystallization mechanism concepts and then analyzing their forms in emerging metallic materials, such as high strength steels, Ti- and Mg-based alloys, as well as high-entropy and shape-memory alloys. The reviews on these systems show that the classic recrystallization concepts are still relevant for explaining the recrystallization behavior and by extension to the microstructure development in the materials. However, in some instances, structural factors exclusive to these materials influenced the driving force and recrystallization behavior yielding outcomes sufficiently distinct from that observed in traditional alloys. Basically, deformation processing and material factors such as stress accumulation, inhomogeneous strain distribution, stored energy, available slip systems, phase composition, microstructural variability, initial grain size, texture, stacking fault and lattice distortion energies, strain path, deformation temperature, and solute clustering and diffusion rates were at play in determining the recrystallization mechanisms and kinetics in these emerging metallic materials. Keywords: Recrystallization mechanisms, Microstructure, Deformation processing, Stored energy, Emerging metallic materials