Materials substitution and element replacement

Successful substitution requires maintaining or improving the functional properties of the system. We address the resulting materials technology challenges with a sound understanding of mechanisms, multiscale simulation, and atomistic calculations:

• Magnetic properties: Neodymium-iron-boron (NdFeB) magnets are among the strongest permanent magnets known. Many substitutes (e.g., ferrite magnets) offer lower magnetization and energy density, which would result in larger and heavier components (e.g., in electric motors, wind turbines).
• Optical properties: Rare earth metals such as europium, terbium, and yttrium are used in phosphors for LEDs and displays. Substitutes must have similar emission properties (e.g., color, intensity, service life), which is difficult to achieve.
• Catalytic properties: Cerium is used, for example, in catalysts as an oxygen storage medium. Substitutes must exhibit the same level of reactivity and stability.
• Critical elements often also influence the mechanical properties of materials such as hardness, strength, toughness, and corrosion resistance. Substitutes must meet these requirements.
• Substitute materials must be compatible with existing material systems (e.g., alloys, composites). Problems arise from undesirable phase formation, embrittlement, and intermetallic compounds, which lead to poor processability.

To tackle these challenges together with you, we calculate the properties of your materials systems and develop the appropriate simulation methods for them. Our aim is to create a sound understanding of mechanisms with a reasonable amount of computing power. This opens up new possibilities for you in terms of materials design.

Reference project

High-throughput approaches for reducing rare earths in magnetic materials, KSE

Rare earths are indispensable for the manufacture of cell phones, laptops, electric motors, and wind turbines. However, their availability is critical. In the Fraunhofer Criticality of Rare Earths (KSE) flagship project, seven Fraunhofer institutes jointly developed solutions to reduce dependence on rare earths such as neodymium and dysprosium. From the theoretical prediction of new magnetic materials to the manufacture of practical electric motors with reduced rare earth content, the entire process chain was mapped for the first time. At Fraunhofer IWM, intermetallic phases with favorable hard magnetic properties were identified using materials-theoretical high-throughput screening and information-theoretical data mining. The specially developed web application MagnetPredictor demonstrates how data-driven methods can accelerate materials research.

Project profile: KSE: Criticality of Rare Earths - Fraunhofer IWM

Publications

Krugel, G.; Körner, W.; Urban, D.F.; Gutfleisch, O.; Elsässer, C., High-throughput screening of rare-earth-lean intermetallic 1-13-X compounds for good hard-magnetic properties, Metals 9/10 (2019) 1096 1-13 Link

Körner, W.; Krugel, G.; Urban, D.F.; Elsässer, C., Screening of rare-earth-lean intermetallic 1-11 and 1-11-X compounds of YNi9In2-type for hard-magnetic applications, Scripta Materialia 154 (2018) 295-299 Link

Möller, J.; Körner, W.; Krugel, G.; Urban, D.F.; Elsässer, C., Compositional optimization of hard-magnetic phases with machine-learning models, Acta Materialia 153 (2018) 53-61 Link

Körner, W.; Krugel, G.; Elsässer, C.; Theoretical screening of intermetallic ThMn12-type phases for new hard-magnetic compounds with low rare earth content, Scientific Reports 6 (2016) 24686 1-9; 142/2016 Link

Drebov, N.; Martinez-Limia, A.; Kunz, L.; Gola, A.; Shigematsu, T.; Eckl, T.; Gumbsch, P.; Elsässer C.; Ab initio screening methodology applied to the search for new permanent magnetic materials; New Journal of Physics 15 (2013) 125023 1-24 Link

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