Investigation of phase selection hierarchy in Mn–Al alloys

Genc, Ayse Merve
Acar, Ozgun
Turan, Servet
Kalay, Ilkay
Savacı, Umut
Kalay, Yunus Eren
Primarily attributed to the formation of the ferromagnetic τ-phase, near equiatomic composition of Mn–Al have recently received much attention in permanent magnet industry. Several mechanisms have been proposed in literature for the τ-phase formation but controversy still arises regarding the dominating mode. In the current work, MnAl-based alloys having different compositions in a range between Mn50.5Al49.5 and Mn57Al43 have been studied by means of in-situ high energy X-ray diffraction, differential scanning calorimetry (DSC) and magnetic measurements. Synchrotron and DSC experiments showed the dependence of the τ-MnAl on the intermediate disordered ε0-phase. Alloys having 53.4 at% or less Mn (S1, S2) followed a transformation route of εþε’→τ→βþγ2 upon annealing. Alloys having more than 53.4 at% of Mn had only ε-phase. High energy X-ray diffraction pat-terns showed that ε-phase directly transformed into stable phases in the absence of ε0-phase. It is observed that ε0not only promoted the ferromagnetic τ-phase but also stabilized it by delaying the nucleation of stable phases
Citation Formats
A. M. Genc, O. Acar, S. Turan, I. Kalay, U. Savacı, and Y. E. Kalay, “Investigation of phase selection hierarchy in Mn–Al alloys,” Intermetallics, vol. 115, pp. 0–0, 2019, Accessed: 00, 2020. [Online]. Available: