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

Result code in 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>

Result on the web

<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>

Result language

angličtina

Original language name

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

Original language description

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

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

20500 - Materials engineering

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

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

Publication year

2015

Confidentiality

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

Name of the periodical

Journal of Magnetism and Magnetic Materials

ISSN

0304-8853

e-ISSN

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Volume of the periodical

374

Issue of the periodical within the volume

1

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

6

Pages from-to

427-432

UT code for WoS article

000344949000069

EID of the result in the Scopus database

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