Parameter determination of an analytical model for phase transformation kinetics: Application to crystallization of amorphous Mg–Ni alloys

Abstract

This study used an analytical model for phase-transformation kinetics. We used different combinations of various nucleation mechanisms [mixed nucleation (site saturation plus continuous nucleation), Avrami nucleation, and site saturation plus Avrami nucleation] and growth mechanisms (volume diffusion-controlled growth and interface-controlled growth) for a single transformation. Our work incorporated the effect of impingement of the growing particles. These factors have been applied to the same experimental results to find out the prevailing mechanisms. We made a detailed analysis for the determination of the parameters of the analytical phase-transformation model, in order to determine the most reasonable nucleation and growth modes, and the values for the activation energies of nucleation and growth. We used the model to study the crystallization kinetics of Mg82Ni18 and Mg88.7Ni11.3, as measured by means of both isothermal and isochronal differential scanning calorimetry.