Study of alpha-sigma phase transformation in mechanically alloyed Fe-Cr-Sn alloys

The solubility of tin is significantly extended by mechanical alloying in near equiatomic Fe-Cr alloys. The influences of Sn concentration and of grain size on the kinetics of formation of the a-phase have been studied using different techniques. The sigma -phase formation is much faster for as-milled alloys than it is for conventional alloys. The sigma -phase formation rate decreases with the increase of Sn concentration in alloys with nanometer-sized grains as it does in coarse-grained alloys. The mechanisms which are responsible for the slowing-down of the alpha-sigma transformation are different in both kinds of alloys.