Ni56Mn25-xCuxGa19 (x=0, 1, 2, 4, 8) high-temperature shape-memory alloys
Ni56Mn25-xCuxGa19 (x=0, 1, 2, 4, 8) high-temperature shape-memory alloys
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Ni56Mn25→xCuxGa19 (x = 0, 1, 2, 4, 8) 高温形状记忆合金
DOI：
10.1016/j.jallcom.2008.07.016
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发表时间：
2009-03-05
影响因子：
6.2
通讯作者：
Liu, Xingjun
中科院分区：
文献类型：
--
作者：
Ma, Yunqing;Yang, Shuiyuan;Liu, Xingjun
研究了Ni56Mn25-xCuxGa19 （x = 0,1,2,4,8）合金作为高温形状记忆合金（sma）的显微组织、马氏体相变行为和高温形状记忆效应。这些合金在x < 2时表现为单马氏体相，具有四方结构；在x >= 2时表现为含有马氏体和γ相的双相，具有fcc结构。在Ni56Mn25-xCuxGa19 （x = 0,1,2,4,8）合金中，反向马氏体相变的峰值温度A(p)从x = 0时的452.4℃单调增加到x = 2时的529.9℃。但当Cu含量大于2 at时。在γ相形成时，A(p)在530℃左右几乎保持不变。马氏体相变温度和形状记忆效应随Cu含量的变化与尺寸因子、电子浓度和γ相析出的变化有关。γ相的引入有利于提高NiMnGa合金的热加工性能和塑性，但不利于其形状记忆效应。(C) 2008 Elsevier B.V.版权所有
Ni56Mn25-xCuxGa19 (x = 0, 1, 2, 4, 8) alloys were investigated as high-temperature shape-memory alloys (SMAs), with regards to their microstructure, martensitic transformation behavior as well as high-temperature shape-memory effect. These alloys exhibit single martensitic phase with tetragonal structure for x < 2, and dual phases containing martensite and gamma phase with fcc structure for x >= 2. The peak temperature A(p) for reverse martensitic transformations increases monotonically from 452.4 degrees C for x = 0 to 529.9 degrees C for x = 2 in Ni56Mn25-xCuxGa19 (x = 0, 1, 2, 4, 8) alloys. But when the Cu content is higher than 2 at.%, A(p) remains almost constant at about 530 degrees C upon formation of the gamma phase. The variations of the martensitic transformation temperatures and shape-memory effects with Cu contents correlate with changes in size factor, electron concentration and precipitation of the gamma phase. The introduction of gamma phase is helpful to improve the hot workability and ductility of NiMnGa alloy, but deleterious to the shape-memory effect. (C) 2008 Elsevier B.V. All rights reserved.