Higher order analysis of the distribution of crystallization processes in metallic glasses

Metallic glassy alloys prepared by rapid quenching are expected to exhibit, unlike conventional polycrystalline matter, several specific features. The existence of disorder (frozen metastable state), chemical SRO, structural SRO (clusters), local heterogeneity, occurrence of ordered, yet noncrystalline, groups of atoms in the amorphous matter necessarily must be reflected in the complexity of processes controlling crystallization. Experimental observations on crystallization of amorphous alloys interpreted via classical thermodynamic analyses (which result usually in a single value, sum of values or prescribed activation energy distribution) provide further indication that these processes are numerous and should be more realistically described by a distribution reflecting the thermodynamic distribution of the initial state of the structure. These processes are by no means sufficiently described by standard simple theoretical distributions. Using a numerical Laplace inversion method, it has been possible to determine the distribution of processes controlling crystallization of metallic glasses in time and parametrically against temperature without assumptions concerning the form of the distributions. The results obtained from the changes of electrical resistivity in the course of isothermal crystallization of Fe–Co–B metallic glass have been analysed with respect to the expected inherent complexity of the system.