Functional stability of a ferromagnetic polycrystalline Ni2MnGa high temperature shape memory alloy
File(s)
Accepted version
Author(s)
Azeem, MA
Jones, NG
Raghunathan, SL
Vorontsov, VA
Dye, D
Type
Journal Article
Abstract
Electrocaloric Ni
2
MnGa is of interest for solid state refrigeration applications, as well as a high temperature thermal shape memory
alloy. Here, polycrystalline Ni
54
Mn
25
Ga
21
is examined using in situ synchrotron X-ray di
raction. The initial martensite (
M
f
) and
austenite (
A
f
) finish temperatures were found to be 232
C and 298
C respectively.
M
f
was observed to decline by 8
C
/
cycle
and
A
f
increased by 1
C
/
cycle. Both below and surprisingly, above the Curie temperature, the application of an e.m.f. was
found to a
ect the lattice parameters measured. A change in the thermal expansion of the two phases was found around the Curie
temperature.
2
MnGa is of interest for solid state refrigeration applications, as well as a high temperature thermal shape memory
alloy. Here, polycrystalline Ni
54
Mn
25
Ga
21
is examined using in situ synchrotron X-ray di
raction. The initial martensite (
M
f
) and
austenite (
A
f
) finish temperatures were found to be 232
C and 298
C respectively.
M
f
was observed to decline by 8
C
/
cycle
and
A
f
increased by 1
C
/
cycle. Both below and surprisingly, above the Curie temperature, the application of an e.m.f. was
found to a
ect the lattice parameters measured. A change in the thermal expansion of the two phases was found around the Curie
temperature.
Date Issued
2016-12-29
Date Acceptance
2016-12-09
Citation
Scripta Materialia, 2016, 130, pp.274-277
ISSN
1359-6462
Publisher
Elsevier
Start Page
274
End Page
277
Journal / Book Title
Scripta Materialia
Volume
130
Copyright Statement
© 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
British Council (India)
Rolls-Royce Plc
Engineering & Physical Science Research Council (EPSRC)
Grant Number
IND/CONT/06-07/164E
N/A
EP/H004882/1
Subjects
Science & Technology
Technology
Nanoscience & Nanotechnology
Materials Science, Multidisciplinary
Metallurgy & Metallurgical Engineering
Science & Technology - Other Topics
Materials Science
Ferromagnetic shape memory alloy
Synchrotron radiation
Thermal expansion
Intermetallic compounds
FIELD-INDUCED STRAIN
CRYSTAL-STRUCTURE
MAGNETIC-FIELD
MARTENSITIC-TRANSFORMATION
PHASE-TRANSFORMATION
GIANT
NI54MN25GA21
EVOLUTION
BEHAVIOR
DETECTOR
Materials
0912 Materials Engineering
0913 Mechanical Engineering
Publication Status
Published