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Home > Issues > RetrieveComparison of Hot-deformation Behavior and Magnetic Properties between Nd-Fe-B HDDR and MQU-F Powder
Journal of Magnetics, Volume 25, Number 1, 31 Mar 2020, Pages 29-35
Jae-Gyeong Yoo (Powder & Ceramics Division, Korea Institute of Materials Science, 797 Changwon-daero, Changwon 51508, Republic of Korea), Hee-Ryoung Cha (Powder & Ceramics Division, Korea Institute of Materials Science, 797 Changwon-daero, Changwon 51508, Republic of Korea), Dong-Hwan Kim (Research Center of SG Tech., Star Group Ind. Co., Ltd., 49, Dalseo-daero 85-gil, Dalseo-gu, Daegu, Republic of Korea), Yang-Do Kim * 
(Department of Materials Science and Engineering, Pusan National University, 2, Busandaehak-ro 63beon-gil, Geumjeong-gu,), Jung-Goo Lee * (Powder & Ceramics Division, Korea Institute of Materials Science, 797 Changwon-daero, Changwon 51508, Republic of Korea)
(Department of Materials Science and Engineering, Pusan National University, 2, Busandaehak-ro 63beon-gil, Geumjeong-gu,), Jung-Goo Lee * (Powder & Ceramics Division, Korea Institute of Materials Science, 797 Changwon-daero, Changwon 51508, Republic of Korea)
Abstract
Hot-deformation behavior of Nd-Fe-B HDDR powder was investigated in order to understand the difference in
texturing mechanism of HDDR and MQU-F powder during hot-deformation. The composition of the HDDR
powder was the same as that of MQU-F powder. However, the grain size of HDDR powder (~300 nm) was eight
times larger than that of MQU-F powder (~40 nm). After being subjected to hot-pressing at 700 °C under 200
MPa in a vacuum, the grains of the magnets made from HDDR powder and MQU-F powder have globular
and platelet shapes, respectively. The remanence was 12.2 kG after die-upsetting process at the strain of 0.5.
And it increased up to 13 kG at the strain of 1.4 although the grains still maintained globular-like shapes. The
remanence of 13 kG was almost the same as that obtained the magnet from MQU-F powder at the same deformation
condition. These results indicate that the hot-deformation behavior is quite different between HDDR
and MQU-F powder.
texturing mechanism of HDDR and MQU-F powder during hot-deformation. The composition of the HDDR
powder was the same as that of MQU-F powder. However, the grain size of HDDR powder (~300 nm) was eight
times larger than that of MQU-F powder (~40 nm). After being subjected to hot-pressing at 700 °C under 200
MPa in a vacuum, the grains of the magnets made from HDDR powder and MQU-F powder have globular
and platelet shapes, respectively. The remanence was 12.2 kG after die-upsetting process at the strain of 0.5.
And it increased up to 13 kG at the strain of 1.4 although the grains still maintained globular-like shapes. The
remanence of 13 kG was almost the same as that obtained the magnet from MQU-F powder at the same deformation
condition. These results indicate that the hot-deformation behavior is quite different between HDDR
and MQU-F powder.
Keywords: Nd-Fe-B; HDDR; Hot-deformation
DOI: https://doi.org/10.4283/JMAG.2020.25.1.029
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