Crystallization kinetic studies: A means to evaluate time-temperature-transformation curves. Application to metallic glasses

Abstract

It is shown that the study of the kinetics of crystallization of an amorphous alloy may be used to obtain the correct form of the low temperature part of the time-temperature-transformation (T-T-T) curves. A unified review of the current kinetics of crystallization studies is presented and the general kinetic equation which gives the reaction rate as a function of temperature and crystalline fraction is shown to contain information related to the T-T-T curves. Finally examples of application to two metallic glasses, Nd3Fe77B20 and Fe67.sColsNbl.sB16, obtained by rapid solidification techniques are presented. The comparison between theory and experiment is satisfactory.