DocumentCode :
73083
Title :
Coercivity Enhancement of HDDR Hot-Pressed Magnets by NdCu Diffusion Treatment
Author :
Lingwen Cai ; Shuai Guo ; Changjiang Yan ; Xiaofeng Zhang ; Renjie Chen ; Lidong Liu ; Don Lee ; Aru Yan
Author_Institution :
Key Lab. of Magn. Mater. & Devices, Ningbo Inst. of Mater. Technol. & Eng., Ningbo, China
Volume :
50
Issue :
11
fYear :
2014
fDate :
Nov. 2014
Firstpage :
1
Lastpage :
3
Abstract :
In order to improve the coercivity of hot-pressed magnets with hydrogenation disproportionation desorption recombination (HDDR) powders being the precursor, diffusion processing of an NdCu eutectic alloy is employed for grain boundary modification, resulting in an increase of coercivity from 15.4 to 17.8 kOe, which leads to a better thermal stability with the temperature coefficient (β) changing from -0.549%/K to -0.519%/K. It is evidently observed that Nd-rich grain boundary layers are formed between the adjacent matrix phase grains as well as in the junction parts after diffusion treatment, which is responsible for the coercivity enhancement of the HDDR hot-pressing magnets. The influence of the microstructure on the coercivity has been further investigated to reveal that the Nd-rich phases occurred during the boundary modification process of the NdCu eutectic alloy decouple the exchange interactions between the grains.
Keywords :
aluminium alloys; boron alloys; cobalt alloys; coercive force; desorption; diffusion; exchange interactions (electron); ferromagnetic materials; gallium alloys; grain boundaries; hot pressing; hydrogenation; iron alloys; magnets; neodymium alloys; thermal stability; zirconium alloys; HDDR hot-pressed magnets; Nd13.5FeCo6.0Zr0.1Al1.5Ga0.5B6.5; NdCu; coercivity enhancement; diffusion treatment; eutectic alloy; exchange interactions; grain boundary modification; hydrogenation disproportionation desorption recombination; microstructure; temperature coefficient; thermal stability; Amorphous magnetic materials; Coercive force; Magnetic domains; Magnetic resonance imaging; Magnetic tunneling; Perpendicular magnetic anisotropy; Coercivity; diffusion; hot pressing; hydrogenation disproportionation desorption recombination (HDDR);
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/TMAG.2014.2326715
Filename :
6971766
Link To Document :
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