Structural studies of some hydrogen-treated materials related to the HDDR-process of Nd{sub 2}Fe{sub 14}B-based alloys

Journal Article · Wed Nov 01 04:00:00 EST 1995 · IEEE Transactions on Magnetics

DOI:https://doi.org/10.1109/20.489592· OSTI ID:186930

Uehara, M; Tomizawa, H; Hirosawa, S ^[1]; Choi, P; Tomida, T; Maehara, Y ^[2]

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1. Sumitomo Special Metals Co., Ltd., Osaka (Japan)
2. Sumitomo Metal Industries. Ltd., Amagasaki (Japan)

Hydrogen-treated Nd{sub 14.0}Fe{sub 66.9}Co{sub 11.0}Ga{sub 1.0}Zr{sub 0.1}B{sub 7.0} alloys have been examined by means of powder X-ray diffraction (XRD) and electron probe microanalysis (EPMA) to understand the mechanism of the development of magnetic anisotropy in the hydrogenation, decomposition, desorption, and recombination (HDDR) process of Nd{sub 2}Fe{sub 14}B-based alloys. It has been revealed that Nd{sub 2}Fe{sub 14}B phase can coexist in equilibrium with decomposed products, namely, {alpha}-Fe, NdH{sub 2}, and Fe{sub 2}B, in the presence of hydrogen of an atmospheric pressure over the temperature ranging 1,113 to 1,153 K. It was observed that Co and Ga condensed into a Nd{sub 2}Fe{sub 14}B phase during hydrogen-treatments, resulting in a thermodynamically stable Nd{sub 2}(Fe,Co,Ga){sub 14}B compound. Well-developed anisotropic materials were obtained via the HDDR-process when the hydrogen-treatment was accomplished under such conditions that Nd{sub 2}(Fe,Co,Ga){sub 14}B coexists with the decomposed products. All the results give a favorable support to the previous proposal that the crystallographic orientation of the original alloy can be conveyed via the undecomposed Nd{sub 2}Fe{sub 14}B particles throughout HDDR processing.

• OSTI ID: 186930
• Report Number(s): CONF-950404--
• Journal Information: IEEE Transactions on Magnetics, Journal Name: IEEE Transactions on Magnetics Journal Issue: 6Pt2 Vol. 31; ISSN IEMGAQ; ISSN 0018-9464
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON ALLOYS
COBALT ALLOYS
EXPERIMENTAL DATA
FABRICATION
GALLIUM ALLOYS
HYDROGENATION
IRON BASE ALLOYS
MAGNETIC PROPERTIES
MICROSTRUCTURE
NEODYMIUM ALLOYS
ZIRCONIUM ADDITIONS