About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in Magnetism and Magnetic Materials
|
| Presentation Title |
Reaction Pathways in Direct Reduction of Rare Earth Oxides to Magnets |
| Author(s) |
A. Berseneva, D. Schlagel, O. Palasyuk, R. Kuchi, R. Smaha, Y. Mudryk, I. Hlova, Matthew J. Kramer |
| On-Site Speaker (Planned) |
Matthew J. Kramer |
| Abstract Scope |
Traditional production of rare earth (RE) permanent magnets involves melting, casting, milling and sintering. Refining metals from the oxides is costly and an energy intensive process. Light RE metals can be co-reduced from their oxides using Ca in the presence of Fe to produce RE-Fe-based permanent magnets. Scaling-up this process requires a better understanding of the reaction pathways and kinetics: this talk will discuss mechanistic insights into Sm<SUb>2</SUb>Fe<SUb>17</SUb> and Nd<SUb>2</SUb>Fe<SUb>14</SUb>B</SUb> formation via direct oxide reduction. Using both in situ synchrotron XRD and interrupted diffusion reactions, we show that the reduction of the RE<SUb>2</SUb>O<SUb>3</SUb> (RE is Nd or Sm) begins at ~300°C. The intermetallic formation starts at ~500°, well below the eutectic temperature of 640°C for Fe-Nd (680 °C) and for Fe-Sm (720°C) or the Ca melting point (840 °C). We find that the Sm<SUb>2</SUb>Fe<SUb>17</SUb> phase form at the Sm-Fe eutectic temperature, and Nd<SUb>2</SUb>Fe<SUb>14</SUb>B forms closer to 900 °C. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Magnetic Materials, Phase Transformations, |