Significant coercivity enhancement of hot-deformed bulk magnets by two-step diffusion process using a minimal amount of Dy

M. Korent, Xin Tang, H. Sepehri-Amin, K. Hioki, K. Soderžnik, S. Kobe, T. Ohkubo, K. Hono

Research output: Contribution to journalArticlepeer-review

Abstract

This work has demonstrated that a high coercivity of 2.5 T can be achieved in a 5.6-mm-thick Nd-Fe-B anisotropic magnet by applying the two-step diffusion process using Nd50Dy30Cu20 and Nd80Cu20 eutectic alloys to a Dy-free Nd-Fe-B hot-deformed magnet. This is in contrast to the fact that about 5 wt.% Dy was needed to reach this coercivity level in sintered magnets. The overall Dy concentration in the sample was determined to be only 0.45 wt.% Dy, which is about 10 % of that used in the conventional Dy-alloyed sintered magnets with a comparable coercivity. Due to the low Dy concentration, a relatively high remanence of 1.32 T is retained even after the two-step diffusion process with an excellent temperature coefficient of coercivity of –0.41 %/°C.

Original languageEnglish
Article number114207
JournalScripta Materialia
Volume205
DOIs
Publication statusPublished - 2021 Dec
Externally publishedYes

Keywords

  • Coercivity
  • Hot-deformed magnets
  • Nd-Fe-B
  • Permanent magnet
  • Remanence

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys

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