Influence of Ni on martensitic phase transformations in NiTi shape memory alloys
Influence of Ni on martensitic phase transformations in NiTi shape memory alloys
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DOI：
10.1016/j.actamat.2010.02.019
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发表时间：
2010-05-01
期刊：
影响因子：
9.4
通讯作者：
Eggeler, G.
中科院分区：
文献类型：
--
作者：
Frenzel, J.;George, E. P.;Eggeler, G.
获得了NiTi相变温度的高精度数据，包括Ni对M（S），M（F），A（S），A（F）和T（0）影响的数值表达式，并讨论了以往研究中观察到的大的实验分散性的原因。提供了明确的实验证据，证实了Tang等人1999 [19]关于热力学平衡温度与Ni浓度之间线性关系偏差的预测。除了影响相变温度，增加Ni含量被发现减少热滞后的宽度和转变热。根据Prokoshkin等人2004 [68]的晶体学数据以及Ball和James [25]的理论，这些发现是合理的。结果表明，重要的是要仔细记录的电弧熔炼过程中使用的形状记忆合金的细节，如果处理的效果是适当的占，精确的值的Ni浓度的NiTi矩阵可以得到。(C)2010 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
High-precision data on phase transformation temperatures in NiTi, including numerical expressions for the effect of Ni on M(S), M(F), A(S), A(F) and T(0), are obtained, and the reasons for the large experimental scatter observed in previous studies are discussed. Clear experimental evidence is provided confirming the predictions of Tang et al. 1999 [19] regarding deviations from a linear relation between the thermodynamic equilibrium temperature and Ni concentration. In addition to affecting the phase transition temperatures, increasing Ni contents are found to decrease the width of thermal hysteresis and the heat of transformation. These findings are rationalized on the basis of the crystallographic data of Prokoshkin et al. 2004 [68] and the theory of Ball and James [25]. The results show that it is important to document carefully the details of the arc-melting procedure used to make shape memory alloys and that, if the effects of processing are properly accounted for, precise values for the Ni concentration of the NiTi matrix can be obtained. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.