Thermo-kinetic connectivity by integrating thermo-kinetic correlation and generalized stability

Abstract

• A negative driving force integrating strain energy, interface energy and any kind of energy that inhibits phase transformations was proposed. • Unified expressions of thermo-kinetic correlation and generalized stability were derived for different types of phase transformation. • A thermo-kinetic connectivity was achieved by similar thermo-kinetic correlation and generalized stability between phase transformations and plastic deformations. • A criterion of high driving force-high generalized stability was discussed to achieve structural materials with excellent strength-plasticity combinations. Designing structured materials with optimized mechanical properties generally focuses on engineering microstructures, which are closely determined by the processing routes, such as phase transformations (PTs) and plastic deformations (PDs). Both PTs and PDs follow inherent trade-off relation between thermodynamic driving force Δ G and kinetic energy barrier Q , i.e., so-called thermo-kinetic correlation. By analyzing nucleation and growth and proposing a conception of negative driving force integrating strain energy, interface energy and any kind of energy that equivalently inhibits the PT itself, Δ G S , unified expressions for the thermo-kinetic correlation and generalized stability (GS) were derived for three kinds of PTs, i.e., diffusive PTs with simultaneously decreased Δ G and increased Q , diffusive PTs with simultaneously increased Δ G and decreased Q , and displacive PTs with simultaneously increased Δ G and decreased Q . This leads to so-called thermo-kinetic connectivity by integrating the thermo-kinetic correlation and the GS, where, by application in typical PTs, it was clearly shown, a criterion of high Δ G -high GS can be predicted by modulating chemical driving force, negative driving force and kinetic energy barrier for diffusion or nucleation. Following thermo-kinetic connectivity, analogous procedure for dislocation evolution upon PDs was performed, and materials design in terms of the high Δ G -high GS criterion was discussed and prospected.