Grain refinement in heavy rare earth element-free sintered Nd–Fe–B magnets by addition of a small amount of molybdenum
Abstract
We employed a modified refractory-metal-addition method to achieve higher coercivity and remanence in heavy rare earth element (HREE)-free Nd–Fe–B sintered magnets. This process involved inducing the formation of a homogeneous secondary phase at the grain boundaries during sintering, making it possible to control the intergrain diffusion by adding small amounts of Mo, a refractory metal. To control the microstructure of the secondary phase effectively, a metal organic compound of the refractory metal was coated on the surfaces of the particles of an HREE-free Nd–Fe–B powder. The average grain size after this process was 5.60 μm, which was approximately 1.8 μm smaller than that of the HREE-free sintered Nd–Fe–B magnets (7.4 μm). The coercivity of the magnets prepared through this process could be increased from 11.88 kOe to 13.91 kOe without decreasing their remanence.
- Authors:
-
- Korea Automotive Technology Institute (KATECH), Cheonan-si 330-912 (Korea, Republic of)
- Publication Date:
- OSTI Identifier:
- 22409963
- Resource Type:
- Journal Article
- Journal Name:
- Journal of Applied Physics
- Additional Journal Information:
- Journal Volume: 117; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; APPROXIMATIONS; BORON ALLOYS; COERCIVE FORCE; DIFFUSION; GRAIN BOUNDARIES; GRAIN REFINEMENT; GRAIN SIZE; IRON ALLOYS; MAGNETIC MATERIALS; MAGNETS; MOLYBDENUM; MOLYBDENUM ADDITIONS; NEODYMIUM ALLOYS; ORGANOMETALLIC COMPOUNDS; POWDERS; SINTERING; SURFACES
Citation Formats
Kim, Jin Woo, Lee, Won Suk, Byun, Jong Min, Kim, Young Do, E-mail: ydkim1@hanyang.ac.kr, and Kim, Se Hoon. Grain refinement in heavy rare earth element-free sintered Nd–Fe–B magnets by addition of a small amount of molybdenum. United States: N. p., 2015.
Web. doi:10.1063/1.4916496.
Kim, Jin Woo, Lee, Won Suk, Byun, Jong Min, Kim, Young Do, E-mail: ydkim1@hanyang.ac.kr, & Kim, Se Hoon. Grain refinement in heavy rare earth element-free sintered Nd–Fe–B magnets by addition of a small amount of molybdenum. United States. https://doi.org/10.1063/1.4916496
Kim, Jin Woo, Lee, Won Suk, Byun, Jong Min, Kim, Young Do, E-mail: ydkim1@hanyang.ac.kr, and Kim, Se Hoon. 2015.
"Grain refinement in heavy rare earth element-free sintered Nd–Fe–B magnets by addition of a small amount of molybdenum". United States. https://doi.org/10.1063/1.4916496.
@article{osti_22409963,
title = {Grain refinement in heavy rare earth element-free sintered Nd–Fe–B magnets by addition of a small amount of molybdenum},
author = {Kim, Jin Woo and Lee, Won Suk and Byun, Jong Min and Kim, Young Do, E-mail: ydkim1@hanyang.ac.kr and Kim, Se Hoon},
abstractNote = {We employed a modified refractory-metal-addition method to achieve higher coercivity and remanence in heavy rare earth element (HREE)-free Nd–Fe–B sintered magnets. This process involved inducing the formation of a homogeneous secondary phase at the grain boundaries during sintering, making it possible to control the intergrain diffusion by adding small amounts of Mo, a refractory metal. To control the microstructure of the secondary phase effectively, a metal organic compound of the refractory metal was coated on the surfaces of the particles of an HREE-free Nd–Fe–B powder. The average grain size after this process was 5.60 μm, which was approximately 1.8 μm smaller than that of the HREE-free sintered Nd–Fe–B magnets (7.4 μm). The coercivity of the magnets prepared through this process could be increased from 11.88 kOe to 13.91 kOe without decreasing their remanence.},
doi = {10.1063/1.4916496},
url = {https://www.osti.gov/biblio/22409963},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 17,
volume = 117,
place = {United States},
year = {Thu May 07 00:00:00 EDT 2015},
month = {Thu May 07 00:00:00 EDT 2015}
}