Generalised kinetics of overall phase transition useful for glass crystallisation when assuming non-isothermal conditions

Abstract

The modelling of reaction kinetics is a fashionable subject of publications. We developed an analogue of the KJMA equation under non-isothermal conditions α(T)=1−exp(−(T/θ)N) that describes the dependence of degree of transformation α(T) at a constant rate, q, of heating with characteristic temperature θ(q) and power N, proportional to the Avrami parameter, n. This equation is valid even when the activation energy of the process is not constant. We demonstrate that reliable information about the activation energy is obtained when the experimental data are plotted in coordinates: logq (heating rate) against logTp (peak temperature).