Two-way shape memory effect of a TiNiHf high temperature shape memory alloy
Two-way shape memory effect of a TiNiHf high temperature shape memory alloy
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DOI：
10.1016/j.jallcom.2003.10.020
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发表时间：
2004-06
影响因子：
6.2
通讯作者：
Xianyu Meng;Yufeng Zheng;W. Cai;L. C. Zhao
中科院分区：
文献类型：
--
作者：
Xianyu Meng;Yufeng Zheng;W. Cai;L. C. Zhao
通过弯曲试验系统研究了ti36ni49hf15高温形状记忆合金（SMA）的双向形状记忆效应。在TiNiHf合金中，即使在很小的变形应变下，马氏体变形也是获得双向形状记忆效应的有效方法。当合金在完全马氏体状态下变形时，变形机制为马氏体取向伴位错滑移。实验结果表明，弯曲变形形成的内部应力场与弯曲变形形成的优先取向马氏体变体方向一致。在这种取向应力场下，冷却后形成优先取向的马氏体变异体，这应该是双向形状记忆效应的产生原因。适当的训练过程和老化有利于定向应力场的形成，从而提高双向形状记忆效应。当训练应变为7.1%，训练温度为室温时，ti36ni49hf15合金的双向形状记忆应变为0.88%。该值是迄今为止基于ti的高温sma中最大的双向形状记忆应变。与TiNi合金相比，tinhf高温SMA表现出双向形状记忆效应，由于马氏体强度较低，稳定性相对较差。
The two-way shape memory effect in a Ti36Ni49Hf15high temperature shape memory alloy (SMA) has been systematically studied by bending tests. In the TiNiHf alloy, the martensite deformation is an effective method to get two-way shape memory effect even with a small deformation strain. When the TiNiHf alloy is deformed at a full martensite state, the deformation mechanism is the martensite orientation accompanied by the dislocation slip. The experimental results indicated that the internal stress field formed by the bending deformation is in the directions of the preferentially oriented martensite variants formed during the bending deformation. Upon cooling the preferentially oriented martensite variants form under such an oriented stress field, which should be responsible for the generation of the two-way shape memory effect. Proper training process and aging benefit the formation of the oriented stress field, resulting in the improvement of the two-way shape memory effect. When the training strain is 7.1% and the training temperature is room temperature, a two-way shape memory strain of 0.88% is obtained in the Ti36Ni49Hf15alloy. This value is the maximum two-way shape memory strain in the TiNi-based high temperature SMAs so far. In comparison with the TiNi alloy, the TiNiHf high temperature SMA shows the two-way shape memory effect with the relative poor stability due to the lower strength of martensite.