Abstract
High coercivity and anisotropic Nd-Fe-B powders for making anisotropic bonded magnets have been prepared by hydrogenation-disproportionation-desorption-recombination (HDDR). We found that the processing hydrogen pressure is intimately correlated with the formation of c -axis crystal texture of Nd2Fe14B phase. There exists a critical hydrogen pressure, P-{mathrm {crit}} , during hydrogen-disproportionation stage, that promotes the formation of c -axis crystal texture. When processing hydrogen pressure is higher than P-{mathrm {crit}} , the formation of c -axis texture deteriorates and results in isotropic Nd-Fe-B magnetic powders. The existence of P-{mathrm {crit}} is ascribed to the thermodynamics and kinetics origin during HDDR process.
| Original language | English |
|---|---|
| Article number | 9187834 |
| Journal | IEEE Transactions on Magnetics |
| Volume | 57 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2021 |
Funding
ACKNOWLEDGMENT This work was supported in part by the Critical Materials Institute (CMI), an Energy Innovation Hub funded by the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office; in part the Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University of Science and Technology under Contract DE-AC02-07CH11358; and in part by the Oak Ridge National Laboratory, managed by UT-Battelle, LLC, with the U.S. Department of Energy (DOE) under Contract DE-AC05-00OR22725.
| Funders | Funder number |
|---|---|
| Critical Materials Institute | |
| U.S. Department of Energy | |
| Advanced Manufacturing Office | |
| Office of Energy Efficiency and Renewable Energy | |
| Oak Ridge National Laboratory | DE-AC05-00OR22725 |
| Iowa State University | DE-AC02-07CH11358 |
| Ames Laboratory |
Keywords
- Anisotropic powder
- NdFeB
- bonded magnets
- hydrogenation-disproportionation-desorption-recombination (HDDR)
- rare earth