Abstract
Changes in microstructure of Nd-Fe-B based magnetic materials were investigated with advanced electron microscopes to study the Tb diffusion treatment for high coercivity for sintered magnets and the hydrogenation- decomposition-desorption- recombination (HDDR) process for high anistropic magnet powders. In sintered magnets, it was found that morphology of a Nd- rich wetting-layer phase changes to be continuous in shape and uniform in thickness in association with diffusion of Tb. The formation of the continuous Nd-rich wetting-layer phase containing a small amount of Tb leads to an effective increase in coercivity. In the HDDR magnet powder, a recombined Nd 2Fe 14B phase is formed first as a rim phase on spherical NdH 2 grains during the DR-process. Small grain size of NdH 2 phase and large grain size of a-Fe matrix after the HD-process can produce small grains of highly aligned Nd 2Fe 14B that lead to high remanence and high coercivity. These results indicate that a nano-dimensional analysis is essentially important to develop the high-performance of magnetic materials.
| Original language | English |
|---|---|
| Pages (from-to) | 17-26 |
| Number of pages | 10 |
| Journal | Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals |
| Volume | 76 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jan 1 2012 |
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All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Materials Chemistry
- Metals and Alloys
- Condensed Matter Physics
Cite this
Nano-Dimensional analysis of high-performance Nd-Fe-B-Based magnetic materials for micro-structural control. / Itakura, Masaru; Kuwano, Noriyuki.
In: Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, Vol. 76, No. 1, 01.01.2012, p. 17-26.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Nano-Dimensional analysis of high-performance Nd-Fe-B-Based magnetic materials for micro-structural control
AU - Itakura, Masaru
AU - Kuwano, Noriyuki
PY - 2012/1/1
Y1 - 2012/1/1
N2 - Changes in microstructure of Nd-Fe-B based magnetic materials were investigated with advanced electron microscopes to study the Tb diffusion treatment for high coercivity for sintered magnets and the hydrogenation- decomposition-desorption- recombination (HDDR) process for high anistropic magnet powders. In sintered magnets, it was found that morphology of a Nd- rich wetting-layer phase changes to be continuous in shape and uniform in thickness in association with diffusion of Tb. The formation of the continuous Nd-rich wetting-layer phase containing a small amount of Tb leads to an effective increase in coercivity. In the HDDR magnet powder, a recombined Nd 2Fe 14B phase is formed first as a rim phase on spherical NdH 2 grains during the DR-process. Small grain size of NdH 2 phase and large grain size of a-Fe matrix after the HD-process can produce small grains of highly aligned Nd 2Fe 14B that lead to high remanence and high coercivity. These results indicate that a nano-dimensional analysis is essentially important to develop the high-performance of magnetic materials.
AB - Changes in microstructure of Nd-Fe-B based magnetic materials were investigated with advanced electron microscopes to study the Tb diffusion treatment for high coercivity for sintered magnets and the hydrogenation- decomposition-desorption- recombination (HDDR) process for high anistropic magnet powders. In sintered magnets, it was found that morphology of a Nd- rich wetting-layer phase changes to be continuous in shape and uniform in thickness in association with diffusion of Tb. The formation of the continuous Nd-rich wetting-layer phase containing a small amount of Tb leads to an effective increase in coercivity. In the HDDR magnet powder, a recombined Nd 2Fe 14B phase is formed first as a rim phase on spherical NdH 2 grains during the DR-process. Small grain size of NdH 2 phase and large grain size of a-Fe matrix after the HD-process can produce small grains of highly aligned Nd 2Fe 14B that lead to high remanence and high coercivity. These results indicate that a nano-dimensional analysis is essentially important to develop the high-performance of magnetic materials.
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U2 - 10.2320/jinstmet.76.17
DO - 10.2320/jinstmet.76.17
M3 - Article
VL - 76
SP - 17
EP - 26
JO - Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals
JF - Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals
SN - 0021-4876
IS - 1
ER -