Formation mechanism of Tb-rich shell in grain boundary diffusion processed Nd-Fe-B sintered magnets

被引：97

作者：

Kim, Tae-Hoon ^{[1
]}

Sasaki, T. T. ^{[1
]}

Koyama, T. ^{[2
]}

Fujikawa, Y. ^{[3
]}

Miwa, M. ^{[3
]}

Enokido, Y. ^{[3
]}

Ohkubo, T. ^{[1
]}

Hono, K. ^{[1
]}

机构：

[1] Natl Inst Mat Sci, Ctr Magnet Mat, Elements Strategy Initiat, Tsukuba, Ibaraki 3050047, Japan

[2] Nagoya Univ, Dept Mat Design Innovat Engn, Chikusa Ku, Furo Cho, Nagoya, Aichi 4648603, Japan

[3] TDK Corp, Mat Dev Ctr, 570-2 Matsugashita, Minamihadori, Narita 2688588, Japan

来源：

SCRIPTA MATERIALIA | 2020年 / 178卷

关键词：

Permanent magnet; Nd-Fe-B; Coercivity; Grain boundary diffusion; Rare earth; RARE-EARTH-ELEMENTS; COERCIVITY ENHANCEMENT; DY; MICROSTRUCTURE; MIGRATION;

D O I：

10.1016/j.scriptamat.2019.12.002

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

We propose a new mechanism for the formation of Tb-rich shell in the Nd-Fe-B sintered magnet that was subjected to the grain boundary diffusion (GBD) process using TbH2. Tb-enriched liquid films form along grain boundaries during the GBD process, which migrate by chemically induced liquid film migration (CILFM) to form Tb-rich shells behind. As a result, the Tb-rich shell form asymmetrically along a grain boundary with an abrupt concentration change at a core/shell interface with a gradual decrease of Tb concentration toward a grain boundary. These microstructure features can be reproduced with phase-field simulations. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

引用

页码：433 / 437

页数：5

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