Materials design by generalized stability

Phase transformations (PTs) and plastic deformations (PDs) are two essential processes involved in metallic materials design, where, thermodynamics and kinetics due to interface migration in PTs and dislocation evolution in PDs follow analogous thermo-kinetic synergy, i.e., the increased thermodynamic driving force ΔG is simultaneously accompanied by the decreased kinetic energy barrier Q, and vice versa; while the PT determines the microstructure and the dislocation evolution upon PDs reflects the mechanical properties. The classical concept of thermodynamic stability (TS) just determines the difficulty of initiating the PTs and PDs, whereas, the newly proposed concept of generalized stability, considering concurrently thermodynamics and kinetics (thermo-kinetics) after breaking the TS, aims to evaluate the persistence and/or the sustainability for progressing PTs or PDs; a criterion of high ΔG-high GS has been widely applied in metallic materials design. Quantitatively modulating microstructure and mechanical properties can be realized by integrating the TS and the GS, which, as a significant breakthrough, will provide a unified and quantitative strategy for metallic materials design.