Likhtorovych S. Evolution of defect structure of iron- and nickel-based amorphous alloys during structural relaxation and crystallization

The iron- and nickel-based metallic glasses are studied. The goal is to elucidate regularities of the defect structure variation in the metallic glasses in the course of structural relaxation, crystallization, and phase transformations in the crystalline state. Positron annihilation and Mossbauer spectroscopies are the methods of investigation. The defect structure variation of metallic glasses is found to be a multistage process, which includes the quasivacancy annealing stage, stage of inverse annealing due to defect formation during the growth of crystalline nuclei and stages of defect annealing in completely crystallized alloy. The mean radii of quasivacancies in Fe-based metallic glasses do not exceed the radius of the vacancy in b.c.c. Fe. Corrosion resistance of Fe-Cr-P-C alloy is found to increase by almost two orders of magnitude due to an annealing of quasivacancies. The results may be applied in the institutions which manufacture, investigate and utilize metallic glasses.