Functional stability of a ferromagnetic polycrystalline Ni2MnGa high temperature shape memory alloy
Functional stability of a ferromagnetic polycrystalline Ni2MnGa high temperature shape memory alloy
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DOI：
10.1016/j.scriptamat.2016.12.012
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发表时间：
2017-03-15
影响因子：
6
通讯作者：
Dye, D.
中科院分区：
文献类型：
--
作者：
Azeem, M. A.;Jones, N. G.;Dye, D.
电热式Ni2MnGa在固态制冷和高温热形状记忆合金中具有重要的应用价值。本文用同步辐射X射线衍射仪对多晶Ni54Mn25Ga21进行了原位观察。马氏体态(M-f)和奥氏体态(A(F))的初始终轧温度分别为232℃和298℃。观察到M-f下降8摄氏度/周，A(F)增加1摄氏度/周。在居里温度以下和令人惊讶的是，电动势的应用。发现了影响所测晶格参数的因素。在居里温度附近，两相的热膨胀发生了变化。(C)2016 Acta Materialia Inc.由爱思唯尔有限公司出版。版权所有。
Electrocaloric Ni2MnGa is of interest for solid state refrigeration applications, as well as a high temperature thermal shape memory alloy. Here, polycrystalline Ni54Mn25Ga21 is examined using in situ synchrotron X-ray diffraction. The initial martensite (M-f) and austenite (A(f)) finish temperatures were found to be 232 degrees C and 298 degrees C respectively. M-f was observed to decline by 8 degrees C/cycle and A(f) increased by 1 degrees C/cycle. Both below and surprisingly, above the Curie temperature, the application of an e.m.f. was found to affect the lattice parameters measured. A change in the thermal expansion of the two phases was found around the Curie temperature. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.