Primary crystallization in Fe65Nb10B25 metallic glass

Abstract The kinetic analysis of primary crystallization under heat treatment of Fe65Nb10B25 metallic glass is obtained from quantitative microstructural data in combination with calorimetric data. The mathematical description is grounded on the Kolmogorov–Johnson–Mehl–Avrami model generalized to account for the compositional changes of the parent phase, responsible for the decreasing of both the nucleation frequency and the growth rate of the primary grains. The modeling and calculation of the transformation rate has been performed to determine the optimum range of values of the viscosity, driving force for crystallization and interfacial energy, leading to a reasonable agreement with the experimental kinetic data. It is shown that the indicated modeling procedure is quite suitable to obtain an indirect evaluation of the interfacial energy between Fe23B6-type nanocrystals and a disordered matrix with global Fe65Nb10B25 composition.