Ball-milling in vacuum of α and σ phases of near-equiatomic FeCr alloys

The structural changes induced by ball-milling of near-equiatomic σ-FeCr and α-FeCr in vacuum were followed. Besides the α-phase, an amorphous phase appears when milling the σ-phase for times longer than 20 h. An amorphous phase forms too, but at a slower rate than the latter, when milling the α-phase. The partial amorphisation of σ-FeCr and α-FeCr ball-milled in vacuum is concluded to be a phenomenon of intrinsic origin. The amorphous phase crystallizes into a bcc Cr-rich phase and a bcc Fe-rich phase during short annealing steps.