Presentation Information
[O1-1]A critical review of permanent magnet materials: options for reduction, substitution and recycling of strategic elements
*Oliver Gutfleisch1 (1. TU Darmstadt (Germany))
Keywords:
permanent magnet roadmap,critical raw materials,sustainability
Magnets are key enablers for the green energy transition. High performance hard and soft magnets are crucial components of energy-related technologies, such as direct drive wind turbines and e-mobility. They are also important in robotics and automatization, sensors, actuators, and information technology. The magnetocaloric effect (MCE) is the key for new and disruptive solid state-based refrigeration. The rare earth elements (REEs), an important class of the critical raw materials (CRMs), are essential constituents of the highest performing magnets and are highlighted in the raw and advanced materials flow essential for (EU) Industrial Ecosystems and a net zero emission scenario. They are also very much in the focus of the most recent geopolitical turmoil, and the (non-)access to REEs is a strategic instrument in international trade war.
Different mitigation scenarios address the criticality of the strategic REEs; trying to overcome the many bottlenecks along the supply and value chain. Supply deficits endanger the development of technologies which abate the climate change and will also impact on other strategic sectors. This supply chain has to be secure, affordable and sustainable and in order to achieve this, we need the diversification of primary CRMs supply, material science and process solutions for new efficient alloy and microstructure design, substitutional materials and effective short and long loop recycling routes. Assessing these different strategies in terms of their energy needs, CO2 balance, other emissions, all impacting on a price we are paying in the short and long term is a complex task. Considering that this assessment will differ greatly, when the primary magnet making is compared with an application such as an electric vehicle with a certain lifetime, will make an analysis even more complicated.
In my talk, I will highlight some examples of recent progress on:
• Heavy RE reduced/free (avoid Dy and Tb) Nd2Fe14B magnets
• RE lean (1:5 SmCo → 2:14:1 → 2:17 SmCo → 1:12 SmFe)
• free RE (utilize Ce and La) in NdFeB
• potential RE free magnets (MnAl, FeNi, Fe16N2)
• short and long loop recycling
• net shaping by hot deformation
• additive manufacturing
• ML for predictive alloy and microstructure design and high-throughput discovery
and discuss these into the context of the magnetic hardness factor kappa and the Brown paradox.
[1] O. Gutfleisch, M. A. Willard, E. Brück, C. H. Chen, S. G. Sankar, and J. P. Liu, Adv. Mater. 23 (2011) 82.
[2] K.P. Skokov and O. Gutfleisch, Scripta Materialia View Point Set, 154 (2018) 289-294.
[3] T. Gottschall, K.P. Skokov, M. Fries, A. Taubel, I. Radulov, F. Scheibel, D. Benke, S. Riegg, O. Gutfleisch, Progress Report in Advanced Energy Materials 9 no. 34 (2019) 1901322.
[4] L. Han, Z. Rao, I.R. Souza Filho, F. Maccari, Y. Wei, G. Wu, Al. Ahmadian, X. Zhou, O. Gutfleisch, D. Ponge, Z. Li, D. Raabe, Nature 608 (2022) 310.
[5] Y. Wu, X. Liao, W. Zeng, K. Skokov, O. Gutfleisch, H. Wu, Y. Xiao, Y. Xu, X. Wang, K. Yan, Y. Li, H.-T. Zhang, Q. Zhou, Y. Dong, D. Kang, C. Jiang, Acta Materialia 292, 15 (2025) 121029.
[6] Y. Yang, A. Walton, R. Sheridan, K. Güth, R. Gauß, O. Gutfleisch, M. Buchert, B.-M. Steenari, T. Van Gerven, P.T. Jones, K. Binnemans, Journal of Sustainable Metallurgy 3 (2017) 122.
[7] K. Opelt, C.-C. Lin, M. Schönfeldt, J. Gassmann, S. Yoon, O. Gutfleisch, Acta Materialia 270 (2024) 119871
[8] M. Schönfeldt, K. Opelt, M. Hasan, M. Gröninger, D. Jahnke, J. Gassmann, O. Gutfleisch, Advanced Engineering Materials (2025) 2402815 Editors´ choice.
[9] M. Schönfeldt, J. Rossa, K. Opelt, K. Schäfer, L. Schäfer, F. Maccari, M. Jovičević-Klug, T.M. Schwarz, C.-C. Lin, M. Hasan, J. Gassmann, D. Raabe, O. Gutfleisch, Acta Materialia 238 (2025) 120532.
[10] I. Dirba, C.A. Schwöbel, L.V.B. Diop, M. Dürrschnabel, L. Molina-Luna, K. Hofmann, P. Komissinskiy, H.-J. Kleebe, O. Gutfleisch, Acta Mat. 123 (2017) 214.
CONTACT:
Prof. Dr. Oliver Gutfleisch
Material Science
Functional Materials
Technische Universität Darmstadt
Peter-Grünberg-Str. 16
64287 Darmstadt
Germany
oliver.gutfleisch@tu-darmstadt.de
http://www.mawi.tu-darmstadt.de/fm
Different mitigation scenarios address the criticality of the strategic REEs; trying to overcome the many bottlenecks along the supply and value chain. Supply deficits endanger the development of technologies which abate the climate change and will also impact on other strategic sectors. This supply chain has to be secure, affordable and sustainable and in order to achieve this, we need the diversification of primary CRMs supply, material science and process solutions for new efficient alloy and microstructure design, substitutional materials and effective short and long loop recycling routes. Assessing these different strategies in terms of their energy needs, CO2 balance, other emissions, all impacting on a price we are paying in the short and long term is a complex task. Considering that this assessment will differ greatly, when the primary magnet making is compared with an application such as an electric vehicle with a certain lifetime, will make an analysis even more complicated.
In my talk, I will highlight some examples of recent progress on:
• Heavy RE reduced/free (avoid Dy and Tb) Nd2Fe14B magnets
• RE lean (1:5 SmCo → 2:14:1 → 2:17 SmCo → 1:12 SmFe)
• free RE (utilize Ce and La) in NdFeB
• potential RE free magnets (MnAl, FeNi, Fe16N2)
• short and long loop recycling
• net shaping by hot deformation
• additive manufacturing
• ML for predictive alloy and microstructure design and high-throughput discovery
and discuss these into the context of the magnetic hardness factor kappa and the Brown paradox.
[1] O. Gutfleisch, M. A. Willard, E. Brück, C. H. Chen, S. G. Sankar, and J. P. Liu, Adv. Mater. 23 (2011) 82.
[2] K.P. Skokov and O. Gutfleisch, Scripta Materialia View Point Set, 154 (2018) 289-294.
[3] T. Gottschall, K.P. Skokov, M. Fries, A. Taubel, I. Radulov, F. Scheibel, D. Benke, S. Riegg, O. Gutfleisch, Progress Report in Advanced Energy Materials 9 no. 34 (2019) 1901322.
[4] L. Han, Z. Rao, I.R. Souza Filho, F. Maccari, Y. Wei, G. Wu, Al. Ahmadian, X. Zhou, O. Gutfleisch, D. Ponge, Z. Li, D. Raabe, Nature 608 (2022) 310.
[5] Y. Wu, X. Liao, W. Zeng, K. Skokov, O. Gutfleisch, H. Wu, Y. Xiao, Y. Xu, X. Wang, K. Yan, Y. Li, H.-T. Zhang, Q. Zhou, Y. Dong, D. Kang, C. Jiang, Acta Materialia 292, 15 (2025) 121029.
[6] Y. Yang, A. Walton, R. Sheridan, K. Güth, R. Gauß, O. Gutfleisch, M. Buchert, B.-M. Steenari, T. Van Gerven, P.T. Jones, K. Binnemans, Journal of Sustainable Metallurgy 3 (2017) 122.
[7] K. Opelt, C.-C. Lin, M. Schönfeldt, J. Gassmann, S. Yoon, O. Gutfleisch, Acta Materialia 270 (2024) 119871
[8] M. Schönfeldt, K. Opelt, M. Hasan, M. Gröninger, D. Jahnke, J. Gassmann, O. Gutfleisch, Advanced Engineering Materials (2025) 2402815 Editors´ choice.
[9] M. Schönfeldt, J. Rossa, K. Opelt, K. Schäfer, L. Schäfer, F. Maccari, M. Jovičević-Klug, T.M. Schwarz, C.-C. Lin, M. Hasan, J. Gassmann, D. Raabe, O. Gutfleisch, Acta Materialia 238 (2025) 120532.
[10] I. Dirba, C.A. Schwöbel, L.V.B. Diop, M. Dürrschnabel, L. Molina-Luna, K. Hofmann, P. Komissinskiy, H.-J. Kleebe, O. Gutfleisch, Acta Mat. 123 (2017) 214.
CONTACT:
Prof. Dr. Oliver Gutfleisch
Material Science
Functional Materials
Technische Universität Darmstadt
Peter-Grünberg-Str. 16
64287 Darmstadt
Germany
oliver.gutfleisch@tu-darmstadt.de
http://www.mawi.tu-darmstadt.de/fm