Correlation between parameters of Arrhenius-type temperature dependency for effective diffusivity governing glass crystallization

Abstract

The methods for estimation of the effective diffusion coefficients, Deff, governing crystallization of metallic glasses are briefly described and the values of pre-exponential factors, D0, and activation energies, Q, of Arrhenius-type temperature dependencies available in the literature for a number of Fe- and Al-based glasses are reported. It has been shown that the relation between logD0–Q characterizing effective diffusivity are well approximated by straight lines similarly to those found for the migration diffusion coefficients in crystalline and amorphous alloys. It has been found that the parameters A and B of the D0 = Aexp(Q/B) correlations for effective diffusivity in Fe- and Al-based glasses essentially differ from those characterizing the migration diffusion in crystalline metals and are closer to the characteristics of impurity diffusivity in metallic glasses. It has been demonstrated that the values of A and B are dependent in the nature of the base element of alloy. The possible mechanism of the effective diffusion at the crystal/glass interfaces is discussed.