Metastable–solid phase diagrams derived from polymorphic solidification kinetics

Significance

Kinetic stabilization of metastable phases in rapidly cooled metals and alloys has been established in experiments for decades. However, atomistic theories that can quantitatively predict the solidification conditions that produce nonequilibrium phases are still in their infancy. Recent advances in pulsed power/laser technologies, as well as in situ characterization, have brought to bear unprecedented understanding of matter at extreme temperatures and pressures. However, accurate predictions of kinetic stabilization of metastable phases that are necessary for physical interpretation of these experiments are lacking. This work provides a blueprint for development of kinetic phase maps of materials undergoing rapid solidification from first principles. Through atomistic simulations, the phases dominating nucleation are identified, and their kinetic stabilities during the growth stage are characterized.