Peculiarities of Mechanical Alloying of High-Concentration Fe–Cr Alloys

Resumo

The kinetics of the mechanical alloying of Fe and Cr powder mixtures with Cr contents of 20–48 at % has been studied by Mössbauer spectroscopy, X-ray diffraction analysis, and temperature measurements of dynamic magnetic susceptibility. It has been found for the first time that the processes of mechanical alloying differ for initial mixtures with chromium contents of 30 at % or more and contents of less than 30 at %. For the first case, the unidirectional dissolution of Cr in Fe is observed through the whole process of mechanical alloying of the mixture in a planetary ball mill. For the second case, the dissolution of Cr in Fe is observed at the beginning stage of milling; however, after milling for 2 h (t_mil), the reverse process, namely, the dissolution of Fe in Cr is likely to dominate. The mechanically alloyed samples are characterized by inhomogeneous Cr and Fe concentration distribution in powder particles, in particular at a Cr concentration in the initial mixture of more than 30 at %.