Theoretical investigations on melting/crystallization kinetics in overheated/overcooled aluminum at high pressures

Abstract

In this study, we developed a theoretical model that explores material melting and crystallization kinetics at high pressures by combining the Kolmogorov-Johnson-Mehl-Avrami kinetics model with equations pulled from hydrodynamic and thermodynamic theories. Our model only requires two inputs: an equilibrium melting curve and an equation of state, both of which can be derived empirically through experiments. We use our model to investigate the melting and crystallization behaviors of aluminum at high pressures. At a constant homologous temperature, our model predicts that melting rates will increase, crystallization growth rates will decrease, and the minimum isothermal crystallization time will increase as pressure increases. Additionally, higher pressures also reduce the critical homologous temperature at which the isothermal crystallization time is at the minimum.