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Advances in Materials Research Volume 9, Number 4, December 2020 , pages 323-335 DOI: https://doi.org/10.12989/amr.2020.9.4.323 |
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Recent developments of manganese-aluminium as rare-earth-free magnets |
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Chitnarong Sirisathitkul
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| Abstract | ||
| This article reviews findings and progresses in the past decade on manganese-aluminium (MnAl) based magnets as the interest has been revived to fulfill their potential as commercial magnets. The challenges in developments of these rare-earth-free magnets are to acquire a high remanence and coercivity from the ferromagnetic τ-phase in MnAl alloys. To this end, the phase transformation to this τ-MnAl with L10 body centered tetragonal structure has been promoted by a variety of methods and a few percents of carbon (C) is often added to prevent the phase decomposition. Magnetization and coercivity are not only influenced by the phase composition but also the microstructure. The fabrication processes and factors affecting the phase and microstructure are therefore covered. Finally, the productions of bulk MnAl magnets are addressed. | ||
| Key Words | ||
| rare-earth-free magnet; manganese-aluminium; ferromagnetic phase; coercivity; magnetization | ||
| Address | ||
| (1) Division of Physics, School of Science, Walailak University, 222 Thaiburi, Thasala, Nakhon Si Thammarat, 80160, Thailand; (2) Thailand Center of Excellence in Physics, Ministry of Higher Education, Science, Research and Innovation, 328 Si Ayutthaya Road, Bangkok 10400, Thailand; (3) Functional Materials and Nanotechnology Center of Excellence, Walailak University, 222 Thaiburi, Thasala, Nakhon Si Thammarat, 80160, Thailand. | ||
