Mössbauer Analysis of Fe94−xNb6Bx (x = 9, 14, 20) Alloys Developed by Mechanical Alloying

The alloys were prepared by milling elemental powders in a planetary ball mill. XRD analysis of the powders indicate that a nanocrystalline heterogeneous bcc alloy was obtained. DSC study of the thermal stability of the powders obtained indicate that some grain growth and reordering of the structure was obtained at temperatures as low as 350°C up to 600°C. Room temperature Transmission Mossbauer spectroscopy from the as milled alloys as well as from the annealed alloys was performed to determine the structure, homogeneity and how the structure changed after annealing at 600°C. The results indicate that the as milled alloys are mainly a crystalline bcc alloy containing most of the Fe, Nb and B. A small amount of a disordered/amorphous phase is also formed for the three alloys. Annealing of the to B richer alloys results in the diffusion of most of the B outside the alloy structure and the crystallization of Fe2B and α‐Fe. Annealing the heterogeneous as‐milled powders enhances the separation of Fe rich (α‐F...