One step preparation of pure 𝝉-MnAl phase with high magnetization using strip casting method

Abstract

Ferromagnetic phase of Mn-Al exhibits great potential in the rare-earth free permanent magnetic materials due to its high magnetocrystalline anisotropy, high magnetization, high Curie temperature and low cost. In this work, the strip casting technique was applied to prepare MnAl magnetic phase. X-ray diffraction and energy dispersive X-ray analyses indicate that the as-prepared Mn54Al46 strip sample consists of pure τ-MnAl magnetic phase. It is found that the composition of Mn54Al46 is suitable to prepare τ-MnAl phase during the strip casting process. The Mn54Al46 strip sample synthesized through the strip casting exhibits a fairly high magnetization of 114 emu/g under a field of 5 T, while the coercivity of iHc = 2.8 kOe, magnetization of M5T = 63.9 emu/g at room temperature can be obtained for Mn54Al46 powder sample. This preparation method can produce a large amount of τ-phase MnAl alloy and promote mass industrialized production.