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  • “Αrtificial Elements”, based on High Entropy Alloys AS BUILDING BLOCKS for NOVEL Magnetic Materials suitable for Permanent Magnets

“Αrtificial Elements”, based on High Entropy Alloys AS BUILDING BLOCKS for NOVEL Magnetic Materials suitable for Permanent Magnets

Dr. D. Niarchos
INN, NCSR Demokritos and AMEN Technologies, Athens, Greece
Thursday, 12 July 2018 12:00

Many developments in modern technology are based in permanent magnets (PMs), including a plentiful of critical applications in the fields of energy, automotive, robotics and more [1]. The most powerful PMs are based on Nd2Fe14B with small addition of Dy and (BH)max  >400 kJ/m3 that can operate at temperatures up to 200 °C. However, as with other RE-based PMs, they are expensive. For higher temperature applications SmCo5 -type magnets are used but with moderate energy products (BH)max ~ 240 kJ/m3. These families and other variants are called RE-magnets and their extreme performance has led to their intensive usage in applications which are not even suitable for older electromagnets. Today, there is an urgent need for the discovery of rare earth free/lean permanent magnets due to the critical strategic character of these metals [2].All these magnets are very brittle that prohibits them for wider applications. On the other hand the new classes of High Entropy Alloys have excellent mechanical properties that might –if incorporated in permanent magnets – will make them less fragile.  In this work we will present our efforts first to synthesize Rare-Earth based HEAs (RE-HEAs) and second the successful efforts to prepare RE-HEAs-Co5 and RE-HEAs-Fe12-xTx (T=Ti,Mo) as confirmed by crystallographic and magnetization data.



References:
[1]  Gutfleisch, O. et al.,. Magnetic materials and devices for the 21st century: Stronger, lighter, and more energy efficient. Advanced Materials, 23(7), pp.821–842 (2011).
[2] ERECON 2014; European Commission 2017
[3]  Yu Zou, et al., Nanocrystalline High Entropy Alloys: A new Paradigm in High-Temperature Strenght and Stability, Nano Lett. 2017, 17, 1569−1574