On the kinetics of spontaneous amorphization of a metastable crystalline phase

The phase transformations of a metastable crystalline phase obtained under high pressure occurring upon heating are considered: amorphization and subsequent crystallization. A model for the kinetics of these processes taking into account the capability for competitive formation of crystalline and amorphous phases at the boundaries of the grains of the initial phase is constructed. Expressions for the volume fractions as well as for the nucleation rates and growth velocities of the phases formed are obtained. Differential scanning calorimetry curves are described. A numerical analysis of the equations of the kinetics and a comparison with the results from experiment are carried out with reference to Cd43Sb57 alloy.