Affiliation:
1. Department of Chemistry—Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
2. Höganäs AB, Bruksgatan 35, 26333 Höganäs, Sweden
Abstract
Permanent magnets are becoming more and more relevant for modern society. As the most widely used permanent magnets contain rare-earth elements, the increased dependence on these strategic elements is worrisome, and the pursuit for rare-earth free alternatives has become a strategic goal in many countries. The metastable and ferromagnetic τ-phase that forms in the MnAl(C) system is one of the most promising alternatives, and since its discovery, major efforts have been made to improve its performance and realize its full potential. One major factor that has prevented a widespread commercialization of MnAl(C) permanent magnets is their relatively low coercivity. Here, we demonstrate that additive manufacturing, using laser powder bed fusion, can be used to produce MnAl in its high-temperature polymorph (ε, hcp), which can be subsequently transformed, through post-heat treatments to the ferromagnetic τ-phase. Although we successfully obtained a preferential orientation of the ε-phase with <001> parallel to the build direction, this did not translate into a strong preferential orientation in the τ-phase, thus indicating that the phase transformation occurs by the migration of incoherent interfaces. The MnAl(C) samples are characterized by a density of ≈4.4 g/cm3, a saturation magnetization of 39.3 Am2/kg, a coercivity of 168 kA/m, and a remanence of 17.5 Am2/kg.
Funder
Swedish Foundation for Strategic Research
Swedish Research Council
Reference22 articles.
1. Permanent magnets: Plugging the gap;Coey;Scr. Mater.,2012
2. Mohapatra, J., and Liu, J. (2018). Handbook of Magnetic Materials, Elsevier B.V.. [1st ed.].
3. Kontos, S., Ibrayeva, A., Leijon, J., Mörée, G., Frost, A., Schönström, L., Gunnarsson, K., Svedlindh, P., Leijon, M., and Eriksson, S. (2020). An overview of MnAl permanent magnets with a study on their potential in electrical machines. Energies, 13.
4. Elemental segregation to twin boundaries in a MnAl ferromagnetic Heusler alloy;Palanisamy;Scr. Mater.,2018
5. Koper, G., and Terpstra, M. (1991). Improving the Properties of Permanent Magnets, Springer.
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