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Structural Change in Ni-Fe-Ga Magnetic Shape Memory Alloys after Severe Plastic Deformation

Severe plastic deformation (SPD) is widely considered to be the most efficient process in obtaining ultrafine-grained bulk materials. The aim of this study is to examine the effects of the SPD process on Ni-Fe-Ga ferromagnetic shape memory alloys (FSMA). High-speed high-pressure torsion (HSHPT) was...

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Autores principales: Gurau, Gheorghe, Gurau, Carmela, Tolea, Felicia, Sampath, Vedamanickam
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6630838/
https://www.ncbi.nlm.nih.gov/pubmed/31212882
http://dx.doi.org/10.3390/ma12121939
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author Gurau, Gheorghe
Gurau, Carmela
Tolea, Felicia
Sampath, Vedamanickam
author_facet Gurau, Gheorghe
Gurau, Carmela
Tolea, Felicia
Sampath, Vedamanickam
author_sort Gurau, Gheorghe
collection PubMed
description Severe plastic deformation (SPD) is widely considered to be the most efficient process in obtaining ultrafine-grained bulk materials. The aim of this study is to examine the effects of the SPD process on Ni-Fe-Ga ferromagnetic shape memory alloys (FSMA). High-speed high-pressure torsion (HSHPT) was applied in the as-cast state. The exerted key parameters of deformation are described. Microstructural changes, including morphology that were the result of processing, were investigated by optical and scanning electron microscopy. Energy-dispersive X-ray spectroscopy was used to study the two-phase microstructure of the alloys. The influence of deformation on microstructural features, such as martensitic plates, intragranular γ phase precipitates, and grain boundaries’ dependence of the extent of deformation is disclosed by transmission electron microscopy. Moreover, the work brings to light the influence of deformation on the characteristics of martensitic transformation (MT). Vickers hardness measurements were carried out on disks obtained by SPD so as to correlate the hardness with the microstructure. The method represents a feasible alternative to obtain ultrafine-grained bulk Ni-Fe-Ga alloys.
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spelling pubmed-66308382019-08-19 Structural Change in Ni-Fe-Ga Magnetic Shape Memory Alloys after Severe Plastic Deformation Gurau, Gheorghe Gurau, Carmela Tolea, Felicia Sampath, Vedamanickam Materials (Basel) Article Severe plastic deformation (SPD) is widely considered to be the most efficient process in obtaining ultrafine-grained bulk materials. The aim of this study is to examine the effects of the SPD process on Ni-Fe-Ga ferromagnetic shape memory alloys (FSMA). High-speed high-pressure torsion (HSHPT) was applied in the as-cast state. The exerted key parameters of deformation are described. Microstructural changes, including morphology that were the result of processing, were investigated by optical and scanning electron microscopy. Energy-dispersive X-ray spectroscopy was used to study the two-phase microstructure of the alloys. The influence of deformation on microstructural features, such as martensitic plates, intragranular γ phase precipitates, and grain boundaries’ dependence of the extent of deformation is disclosed by transmission electron microscopy. Moreover, the work brings to light the influence of deformation on the characteristics of martensitic transformation (MT). Vickers hardness measurements were carried out on disks obtained by SPD so as to correlate the hardness with the microstructure. The method represents a feasible alternative to obtain ultrafine-grained bulk Ni-Fe-Ga alloys. MDPI 2019-06-17 /pmc/articles/PMC6630838/ /pubmed/31212882 http://dx.doi.org/10.3390/ma12121939 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Gurau, Gheorghe
Gurau, Carmela
Tolea, Felicia
Sampath, Vedamanickam
Structural Change in Ni-Fe-Ga Magnetic Shape Memory Alloys after Severe Plastic Deformation
title Structural Change in Ni-Fe-Ga Magnetic Shape Memory Alloys after Severe Plastic Deformation
title_full Structural Change in Ni-Fe-Ga Magnetic Shape Memory Alloys after Severe Plastic Deformation
title_fullStr Structural Change in Ni-Fe-Ga Magnetic Shape Memory Alloys after Severe Plastic Deformation
title_full_unstemmed Structural Change in Ni-Fe-Ga Magnetic Shape Memory Alloys after Severe Plastic Deformation
title_short Structural Change in Ni-Fe-Ga Magnetic Shape Memory Alloys after Severe Plastic Deformation
title_sort structural change in ni-fe-ga magnetic shape memory alloys after severe plastic deformation
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6630838/
https://www.ncbi.nlm.nih.gov/pubmed/31212882
http://dx.doi.org/10.3390/ma12121939
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