Optimizing the microstructure of low-REM Nd-Fe-B sintered magnet using Dy3Co0.6Cu0.4Hx addition

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27360%2F19%3A10244337" target="_blank" >RIV/61989100:27360/19:10244337 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Optimizing the microstructure of low-REM Nd-Fe-B sintered magnet using Dy3Co0.6Cu0.4Hx addition

Original language description

In recent years, the application of various additions (hydrides, oxides, intermetallic compounds, etc.) to powder mixtures for manufacturing Nd-Fe-B magnets shows promise as the method that allows one to increase the hysteretic characteristics of the magnets at the expense of realized grain-boundary diffusion and grain-boundary structuring processes. The hysteretic characteristics of sintered Nd-Fe-B magnets are highly sensitive to their microstructure and composition of phases. This paper is focused on the coercivity enhancement of the near-stoichiometric Nd2Fe14B-based magnet by optimizing microstructure, which included processes of grain boundary diffusion and grain boundary structuring via the application of hydrogenated Dy3Co0.6Cu0.4Hx compound added to the powder mixture. The base alloy having the composition Nd-24.0, Pr-6.5, Dy-0.5, B-1.0, Al-0.2, Fe-balance was prepared by strip-casting technique and subjected to hydrogen decrepitation during heating to 270 oC in a hydrogen flow at a pressure of 0.1 MPa and subsequent 1 h holding at this temperature. Dy3Co0.6Cu0.4 alloy was prepared by arc melting in an argon atmosphere and subjected to homogenizing annealing at 600 oC for 90 h. The subsequent hydrogenation under the conditions used for the decrepitation of the strip-cast alloy. The phase composition of Dy3Co0.6Cu0.4 was studied by X-ray diffraction analysis, DTA and scanning electron microscopy, electron microprobe analysis. Additions of the hydrogenated compound to Nd-Fe-B-based sintered magnets allow us to manufacture magnets with Br = 1.34 T and jHc = 1120 kA/m. The microstructure, phase composition and distributions of REM, Co, Cu for the prepared magnets were investigated by SEM/EDX method. Stability of structure-sensitive parameter, namely, the coercive force jHc of the sintered magnet prepared with 2 wt% of Dy3Co0.6Cu0.4Hx addition was studied. (C) 2019 TANGER Ltd., Ostrava.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

20500 - Materials engineering

Project

<a href="/en/project/LTARF18031" target="_blank" >LTARF18031: Development of physico-chemical and engineering foundations for the initiation of innovative resources-economy technology of high-power and high-coercivity (Nd,R)-Fe-B (R = Pr, Tb, Dy, Ho) low-REM permanent magnets</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

METAL 2019 : conference proceedings : peer reviewed : 28th International Conference on Metallurgy and Materials : May 22nd-24th 2019, Hotel Voronez I, Brno, Czech Republic, EU

ISBN

978-80-87294-92-5

ISSN

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e-ISSN

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Number of pages

8

Pages from-to

1663-1670

Publisher name

Tanger

Place of publication

Ostrava

Event location

Brno

Event date

May 22, 2019

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

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