Mechanism of the texture development in hydrogen-disproportionation-desorption-recombination (HDDR) processed Nd-Fe-B powders

H. Sepehri-Amin; T. Ohkubo; K. Hono; K. Güth; O. Gutfleisch

doi:10.1016/j.actamat.2014.11.003

Mechanism of the texture development in hydrogen-disproportionation-desorption-recombination (HDDR) processed Nd-Fe-B powders

H. Sepehri-Amin, T. Ohkubo, K. Hono, K. Güth, O. Gutfleisch

Research output: Contribution to journal › Article › peer-review

44 Citations (Scopus)

Abstract

Microstructure evolution in Nd_12.8Fe_80.1B_6.6Ga_0.3Nb_0.2 alloy powders at different hydrogen pressures during the hydrogen-disproportionation process PH2HD has been studied in order to understand the underlying mechanism of the texture development during the dynamic hydrogen-disproportionation-desorption-recombination (d-HDDR) process. Transmission electron microscopy showed that Fe₂B grains "memorize" the crystallographic orientation of the initial Nd₂Fe₁₄B phase and transfer it to the recombined Nd₂Fe₁₄B grains in the highly textured sample. 3-D tomography of backscattered electron SEM images showed that recombined Nd₂Fe₁₄B grains nucleate at the interfaces of Fe₂B/NdH₂ phases, which grow through the interfaces of NdH₂/α-Fe phases during the DR process. Boron segregation was found at the NdH₂/α-Fe interfaces, which serve as a boron source for the growth of the recombined Nd₂Fe₁₄B grains. The mechanism of the texture development is discussed based on the microstructure observations and the corresponding evolution of magnetic properties.

Original language	English
Pages (from-to)	42-52
Number of pages	11
Journal	Acta Materialia
Volume	85
DOIs	https://doi.org/10.1016/j.actamat.2014.11.003
Publication status	Published - 2015 Feb 15
Externally published	Yes

Keywords

Microstructure
Nd-Fe-B permanent magnets
Texture
d-HDDR process

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Ceramics and Composites
Polymers and Plastics
Metals and Alloys

Access to Document

10.1016/j.actamat.2014.11.003

Cite this

@article{e31e6a72a3de4d978a36f6e0c28004ce,

title = "Mechanism of the texture development in hydrogen-disproportionation-desorption-recombination (HDDR) processed Nd-Fe-B powders",

abstract = "Microstructure evolution in Nd12.8Fe80.1B6.6Ga0.3Nb0.2 alloy powders at different hydrogen pressures during the hydrogen-disproportionation process PH2HD has been studied in order to understand the underlying mechanism of the texture development during the dynamic hydrogen-disproportionation-desorption-recombination (d-HDDR) process. Transmission electron microscopy showed that Fe2B grains {"}memorize{"} the crystallographic orientation of the initial Nd2Fe14B phase and transfer it to the recombined Nd2Fe14B grains in the highly textured sample. 3-D tomography of backscattered electron SEM images showed that recombined Nd2Fe14B grains nucleate at the interfaces of Fe2B/NdH2 phases, which grow through the interfaces of NdH2/α-Fe phases during the DR process. Boron segregation was found at the NdH2/α-Fe interfaces, which serve as a boron source for the growth of the recombined Nd2Fe14B grains. The mechanism of the texture development is discussed based on the microstructure observations and the corresponding evolution of magnetic properties.",

keywords = "Microstructure, Nd-Fe-B permanent magnets, Texture, d-HDDR process",

author = "H. Sepehri-Amin and T. Ohkubo and K. Hono and K. G{\"u}th and O. Gutfleisch",

note = "Funding Information: This work was in part supported by Japan Science Technology Agency, CREST. Publisher Copyright: {\textcopyright} 2014 Acta Materialia Inc.",

year = "2015",

month = feb,

day = "15",

doi = "10.1016/j.actamat.2014.11.003",

language = "English",

volume = "85",

pages = "42--52",

journal = "Acta Materialia",

issn = "1359-6454",

publisher = "Elsevier Limited",

}

TY - JOUR

T1 - Mechanism of the texture development in hydrogen-disproportionation-desorption-recombination (HDDR) processed Nd-Fe-B powders

AU - Sepehri-Amin, H.

AU - Ohkubo, T.

AU - Hono, K.

AU - Güth, K.

AU - Gutfleisch, O.

PY - 2015/2/15

Y1 - 2015/2/15

N2 - Microstructure evolution in Nd12.8Fe80.1B6.6Ga0.3Nb0.2 alloy powders at different hydrogen pressures during the hydrogen-disproportionation process PH2HD has been studied in order to understand the underlying mechanism of the texture development during the dynamic hydrogen-disproportionation-desorption-recombination (d-HDDR) process. Transmission electron microscopy showed that Fe2B grains "memorize" the crystallographic orientation of the initial Nd2Fe14B phase and transfer it to the recombined Nd2Fe14B grains in the highly textured sample. 3-D tomography of backscattered electron SEM images showed that recombined Nd2Fe14B grains nucleate at the interfaces of Fe2B/NdH2 phases, which grow through the interfaces of NdH2/α-Fe phases during the DR process. Boron segregation was found at the NdH2/α-Fe interfaces, which serve as a boron source for the growth of the recombined Nd2Fe14B grains. The mechanism of the texture development is discussed based on the microstructure observations and the corresponding evolution of magnetic properties.

AB - Microstructure evolution in Nd12.8Fe80.1B6.6Ga0.3Nb0.2 alloy powders at different hydrogen pressures during the hydrogen-disproportionation process PH2HD has been studied in order to understand the underlying mechanism of the texture development during the dynamic hydrogen-disproportionation-desorption-recombination (d-HDDR) process. Transmission electron microscopy showed that Fe2B grains "memorize" the crystallographic orientation of the initial Nd2Fe14B phase and transfer it to the recombined Nd2Fe14B grains in the highly textured sample. 3-D tomography of backscattered electron SEM images showed that recombined Nd2Fe14B grains nucleate at the interfaces of Fe2B/NdH2 phases, which grow through the interfaces of NdH2/α-Fe phases during the DR process. Boron segregation was found at the NdH2/α-Fe interfaces, which serve as a boron source for the growth of the recombined Nd2Fe14B grains. The mechanism of the texture development is discussed based on the microstructure observations and the corresponding evolution of magnetic properties.

KW - Microstructure

KW - Nd-Fe-B permanent magnets

KW - Texture

KW - d-HDDR process

UR - http://www.scopus.com/inward/record.url?scp=84916898822&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84916898822&partnerID=8YFLogxK

U2 - 10.1016/j.actamat.2014.11.003

DO - 10.1016/j.actamat.2014.11.003

M3 - Article

AN - SCOPUS:84916898822

SN - 1359-6454

VL - 85

SP - 42

EP - 52

JO - Acta Materialia

JF - Acta Materialia

ER -

Mechanism of the texture development in hydrogen-disproportionation-desorption-recombination (HDDR) processed Nd-Fe-B powders

Abstract

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this