Correlation between the kinetics of the amorphous-to-nanocrystalline transformation and the diffusion in alloys

Abstract

The amorphous‐to‐nanocrystalline transition was studied on various melt‐spun, ball‐milled, and cluster‐synthesized alloys by means of differential scanning calorimetry. In the framework of a simple model the correlation found between the pre‐exponential factors and activation enthalpies for the crystallization (KISSINGER analysis) can be attributed to the similar correlation which exists for the tracer diffusivities in the respective amorphous alloys. The shift of the present pre‐exponential factors and activation enthalpies towards higher values compared to the diffusion coefficients in the amorphous state indicates a change of the diffusivity due to the amorphous‐to‐nanocrystalline transition. The crystallization kinetics of Fe_73.5Si_13.5B₉Nb₃Cu₁ is discussed in the light of recent self‐diffusion studies of the intermetallic compound Fe₃Si.