Blending powder process for recycling sintered Nd-Fe-B magnets

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27360%2F20%3A10245167" target="_blank" >RIV/61989100:27360/20:10245167 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.mdpi.com/1996-1944/13/14/3049/htm" target="_blank" >https://www.mdpi.com/1996-1944/13/14/3049/htm</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/ma13143049" target="_blank" >10.3390/ma13143049</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Blending powder process for recycling sintered Nd-Fe-B magnets

Popis výsledku v původním jazyce

The wide application of Nd-Fe-B permanent magnets, in addition to rare-earth metal resource constraints, creates the necessity of the development of efficient technologies for recycling sintered Nd-Fe-B permanent magnets. In the present study, a magnet-to-magnet recycling process is considered. As starting materials, magnets of different grades were used, which were processed by hydrogen decrepitation and blending the powder with NdHx. Composition inhomogeneity in the Nd2Fe14B-based magnetic phase grains in the recycled magnets and the existence of a core-shell structure consisting of a Nd-rich (Dy-depleted) core and Nd-depleted (Dy-enriched) shell are demonstrated. The formation of this structure results from the grain boundary diffusion process of Dy that occurs during the sintering of magnets prepared from a mixture of Dy-free (N42) and Dy-containing magnets. The increase in the coercive force of the N42 magnet was shown to be 52%. The simultaneous retention of the remanence, and even its increase, were observed and explained by the improved isolation of the main magnetic phase grains as well as their alignment. (C) 2020 by the authors.

Název v anglickém jazyce

Blending powder process for recycling sintered Nd-Fe-B magnets

Popis výsledku anglicky

The wide application of Nd-Fe-B permanent magnets, in addition to rare-earth metal resource constraints, creates the necessity of the development of efficient technologies for recycling sintered Nd-Fe-B permanent magnets. In the present study, a magnet-to-magnet recycling process is considered. As starting materials, magnets of different grades were used, which were processed by hydrogen decrepitation and blending the powder with NdHx. Composition inhomogeneity in the Nd2Fe14B-based magnetic phase grains in the recycled magnets and the existence of a core-shell structure consisting of a Nd-rich (Dy-depleted) core and Nd-depleted (Dy-enriched) shell are demonstrated. The formation of this structure results from the grain boundary diffusion process of Dy that occurs during the sintering of magnets prepared from a mixture of Dy-free (N42) and Dy-containing magnets. The increase in the coercive force of the N42 magnet was shown to be 52%. The simultaneous retention of the remanence, and even its increase, were observed and explained by the improved isolation of the main magnetic phase grains as well as their alignment. (C) 2020 by the authors.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20500 - Materials engineering

Projekt

<a href="/cs/project/LTARF18031" target="_blank" >LTARF18031: Vývoj fyzikálně-chemických a inženýrských základů pro iniciaci inovativní úsporné technologie výroby vysoce výkonných permanentních magnetů na bázi (Nd,R)-Fe-B (R = Pr, Tb, Dy, Ho) s nízkým obsahem kovů vzácných zemin</a><br>

Návaznosti

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

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

Materials

ISSN

1996-1944

e-ISSN

—

Svazek periodika

13

Číslo periodika v rámci svazku

14

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

9

Strana od-do

—

Kód UT WoS článku

000558033800001

EID výsledku v databázi Scopus

2-s2.0-85088530727