Isotropic bulk exchange-spring magnets with 134 kJ/m3 prepared by spark plasma sintering method

Hideaki Ono, Norihisa Waki, Munekatsu Shimada, Tatsuo Sugiyama, Akira Fujiki, Hiroshi Yamamoto, Masato Tani

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Densification of exchange-spring magnet ribbons of NdxFe85-xCo8V1B6 (x = 7-11) alloys has been investigated. The starting ribbon powders containing amorphous parts were prepared by melt spinning and were compacted by using a Spark Plasma Sintering (SPS) method. SPS is a type of solid compression sintering similar to hot-pressing and the sintering promotion factor is self heat generation by electric discharges between particles when the on-off D.C. pulse is applied. The bulk magnets indicated the springback phenomenon, pointing to multiple phases of the Nd2Fe14B type and the α-Fe type, and had isotropic magnetic properties. With increasing Nd content, Br decreased from 1.05 T to 0.82 T and HcJ increased from 256 kA/m to 832 kA/m. These changes were equivalent to those of the starting ribbons following annealing. The grain sizes of these bulk magnets were about 40 nm when x = 7-11. Under optimum preparation conditions, bulk Nd10Fe75Co8V1B6 magnet indicated (BH)max = 134 kJ/m3 (16.8 MGOe).

Original languageEnglish
Pages (from-to)2552-2554
Number of pages3
JournalIEEE Transactions on Magnetics
Volume37
Issue number4 I
DOIs
Publication statusPublished - 2001 Jul
Externally publishedYes

Fingerprint

Spark plasma sintering
sparks
Magnets
sintering
magnets
ribbons
Sintering
Electric discharges
melt spinning
Melt spinning
electric discharges
hot pressing
heat generation
Heat generation
promotion
Hot pressing
densification
Densification
Powders
Magnetic properties

Keywords

  • Bulk exchange-spring magnets
  • Densification of melt-spun ribbons
  • Isotropic magnetic properties
  • Nd-Fe-Co-V-B system alloys
  • Spark Plasma Sintering method

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Physics and Astronomy (miscellaneous)

Cite this

Isotropic bulk exchange-spring magnets with 134 kJ/m3 prepared by spark plasma sintering method. / Ono, Hideaki; Waki, Norihisa; Shimada, Munekatsu; Sugiyama, Tatsuo; Fujiki, Akira; Yamamoto, Hiroshi; Tani, Masato.

In: IEEE Transactions on Magnetics, Vol. 37, No. 4 I, 07.2001, p. 2552-2554.

Research output: Contribution to journalArticle

Ono, Hideaki ; Waki, Norihisa ; Shimada, Munekatsu ; Sugiyama, Tatsuo ; Fujiki, Akira ; Yamamoto, Hiroshi ; Tani, Masato. / Isotropic bulk exchange-spring magnets with 134 kJ/m3 prepared by spark plasma sintering method. In: IEEE Transactions on Magnetics. 2001 ; Vol. 37, No. 4 I. pp. 2552-2554.
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