Abstract
In the hydrogenation decomposition desorption recombination(HDDR)processed Nd Fe Co B Al Ga Zr magnet powders, influence of the desorption recombination(DR)temperatures on the microstructures was investigated by high resolution scanning electron microscopy and scanning transmission electron microscopy. By applying the DR treatment under high vacuum(DR Step 2)at relative low temperatures about 973 K, we can obtain the excellent texture in which the average size of Nd2Fe14B grains is refined to about 240 nm and the grain boundary(GB)phase is uniformly dispersed around the Nd2Fe14B grains. In the GB phase, furthermore, the Nd composition increases and the(Fe, Co)composition decreases drastically with decreasing the DR temperatures, and then Nd rich GB phase with more than 65 at.%Nd can be formed at 973 K. At 973 K, however, the region with unformed GB phase is remained about 10% of the specimen, which leads to deterioration of the coercivity. It was found that the gently DR treatment is very effective not only for increasing the coercivity but also for improving the squareness in demagnetization curve.
| Original language | English |
|---|---|
| Pages (from-to) | 121-124 |
| Number of pages | 4 |
| Journal | Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals |
| Volume | 82 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Jan 1 2018 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys
- Materials Chemistry
Cite this
Influence of desorption recombination temperatures on microstructure and coercivity of HDDR-processed anisotropic Nd-Fe-B magnet powders. / Takizawa, Rina; Akamine, Hiroshi; Itakura, Masaru; Nishida, Minoru; Katayama, Nobuhiro; Morimoto, Koichiro.
In: Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, Vol. 82, No. 4, 01.01.2018, p. 121-124.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Influence of desorption recombination temperatures on microstructure and coercivity of HDDR-processed anisotropic Nd-Fe-B magnet powders
AU - Takizawa, Rina
AU - Akamine, Hiroshi
AU - Itakura, Masaru
AU - Nishida, Minoru
AU - Katayama, Nobuhiro
AU - Morimoto, Koichiro
PY - 2018/1/1
Y1 - 2018/1/1
N2 - In the hydrogenation decomposition desorption recombination(HDDR)processed Nd Fe Co B Al Ga Zr magnet powders, influence of the desorption recombination(DR)temperatures on the microstructures was investigated by high resolution scanning electron microscopy and scanning transmission electron microscopy. By applying the DR treatment under high vacuum(DR Step 2)at relative low temperatures about 973 K, we can obtain the excellent texture in which the average size of Nd2Fe14B grains is refined to about 240 nm and the grain boundary(GB)phase is uniformly dispersed around the Nd2Fe14B grains. In the GB phase, furthermore, the Nd composition increases and the(Fe, Co)composition decreases drastically with decreasing the DR temperatures, and then Nd rich GB phase with more than 65 at.%Nd can be formed at 973 K. At 973 K, however, the region with unformed GB phase is remained about 10% of the specimen, which leads to deterioration of the coercivity. It was found that the gently DR treatment is very effective not only for increasing the coercivity but also for improving the squareness in demagnetization curve.
AB - In the hydrogenation decomposition desorption recombination(HDDR)processed Nd Fe Co B Al Ga Zr magnet powders, influence of the desorption recombination(DR)temperatures on the microstructures was investigated by high resolution scanning electron microscopy and scanning transmission electron microscopy. By applying the DR treatment under high vacuum(DR Step 2)at relative low temperatures about 973 K, we can obtain the excellent texture in which the average size of Nd2Fe14B grains is refined to about 240 nm and the grain boundary(GB)phase is uniformly dispersed around the Nd2Fe14B grains. In the GB phase, furthermore, the Nd composition increases and the(Fe, Co)composition decreases drastically with decreasing the DR temperatures, and then Nd rich GB phase with more than 65 at.%Nd can be formed at 973 K. At 973 K, however, the region with unformed GB phase is remained about 10% of the specimen, which leads to deterioration of the coercivity. It was found that the gently DR treatment is very effective not only for increasing the coercivity but also for improving the squareness in demagnetization curve.
UR - http://www.scopus.com/inward/record.url?scp=85044964883&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85044964883&partnerID=8YFLogxK
U2 - 10.2320/jinstmet.J2017061
DO - 10.2320/jinstmet.J2017061
M3 - Article
VL - 82
SP - 121
EP - 124
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 - 4
ER -