Processing of Mn–Al nanostructured magnets by spark plasma sintering and subsequent rapid thermal annealing

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F46747885%3A24620%2F15%3A00001525" target="_blank" >RIV/46747885:24620/15:00001525 - isvavai.cz</a>

Výsledek na webu

<a href="http://www.sciencedirect.com/science/article/pii/S0304885314007756" target="_blank" >http://www.sciencedirect.com/science/article/pii/S0304885314007756</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jmmm.2014.08.076" target="_blank" >10.1016/j.jmmm.2014.08.076</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Processing of Mn–Al nanostructured magnets by spark plasma sintering and subsequent rapid thermal annealing

Popis výsledku v původním jazyce

The potential of spark plasma sintering (SPS) in combination with rapid thermal annealing (RTA) for the processing of Mn–Al nanostructured magnets is explored in this study. Ferromagnetic α-Mn alloy powders were processed by high-energy ball milling using Mn and Al as constituent metal elements. The alloying action between Mn and Al due to intensive milling was studied by X-ray diffraction and field-emission scanning electron microscope; while the phase transformation kinetics was investigated using differential scanning calorimetry. The evolution of ferromagnetic properties in the as-milled powders was studied by superconducting quantum interference device (SQUID). Among the Mn–Al alloy powders collected at various milling intervals, the 25 h milled Mn–Al powders showed a good combination of coercivity, Hc and saturation magnetization, Ms; accordingly, these powders were chosen for SPS. The SPS experiments were conducted at different temperatures and its effect on the density, phase composition and magnetic properties of the Mn–Al bulk samples were investigated. Upon increasing the SPS temperature the bulk density was found to increase. The occurrence of equilibrium β-phase with significant amount of γ2-phase was obvious at all the SPS temperatures; however, crystallization of some amount of τ-phase was evident. Irrespective of the SPS temperatures, all the samples demonstrated soft magnetic behavior with Hc and Ms values similar to those obtained for the 25 h milled powders. The magnetic properties of the SPSed samples were significantly improved upon subjecting them to RTA at 1100 K. Through the RTA process, Hc values of 75, 174 and 194 kA/m and Ms values of 19, 21 and 28 A/m2/kg were achieved for the samples SPSed at 773, 873 and 973 K, respectively. The possible reasons for the observed improvement in the magnetic properties of the SPSed samples due to RTA in correlation with their phase composition and microstructure were analyzed and discussed

Název v anglickém jazyce

Processing of Mn–Al nanostructured magnets by spark plasma sintering and subsequent rapid thermal annealing

Popis výsledku anglicky

The potential of spark plasma sintering (SPS) in combination with rapid thermal annealing (RTA) for the processing of Mn–Al nanostructured magnets is explored in this study. Ferromagnetic α-Mn alloy powders were processed by high-energy ball milling using Mn and Al as constituent metal elements. The alloying action between Mn and Al due to intensive milling was studied by X-ray diffraction and field-emission scanning electron microscope; while the phase transformation kinetics was investigated using differential scanning calorimetry. The evolution of ferromagnetic properties in the as-milled powders was studied by superconducting quantum interference device (SQUID). Among the Mn–Al alloy powders collected at various milling intervals, the 25 h milled Mn–Al powders showed a good combination of coercivity, Hc and saturation magnetization, Ms; accordingly, these powders were chosen for SPS. The SPS experiments were conducted at different temperatures and its effect on the density, phase composition and magnetic properties of the Mn–Al bulk samples were investigated. Upon increasing the SPS temperature the bulk density was found to increase. The occurrence of equilibrium β-phase with significant amount of γ2-phase was obvious at all the SPS temperatures; however, crystallization of some amount of τ-phase was evident. Irrespective of the SPS temperatures, all the samples demonstrated soft magnetic behavior with Hc and Ms values similar to those obtained for the 25 h milled powders. The magnetic properties of the SPSed samples were significantly improved upon subjecting them to RTA at 1100 K. Through the RTA process, Hc values of 75, 174 and 194 kA/m and Ms values of 19, 21 and 28 A/m2/kg were achieved for the samples SPSed at 773, 873 and 973 K, respectively. The possible reasons for the observed improvement in the magnetic properties of the SPSed samples due to RTA in correlation with their phase composition and microstructure were analyzed and discussed

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20500 - Materials engineering

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

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

Rok uplatnění

2015

Kód důvěrnosti údajů

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

Název periodika

Journal of Magnetism and Magnetic Materials

ISSN

0304-8853

e-ISSN

—

Svazek periodika

374

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

6

Strana od-do

427-432

Kód UT WoS článku

000344949000069

EID výsledku v databázi Scopus

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