Effect of Current Pulses on Fatigue of Thin NiTi Wires for Shape Memory Actuators
Effect of Current Pulses on Fatigue of Thin NiTi Wires for Shape Memory Actuators
复制标题
电流脉冲对形状记忆执行器细镍钛丝疲劳的影响
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
A. Tuissi
中科院分区：
文献类型：
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作者：
R. Casati;A. Tuissi
形状记忆合金（SMA）由于其独特的性能：超弹性和形状记忆（SM）效应，在许多技术应用中得到了应用。许多努力，以提高性能的SMA电线利用他们作为热致动器也成千上万的循环。与其他已知的SMA相比，近等原子镍钛化合物具有较高的应变可恢复值和良好的循环稳定性，是SM执行器中使用最多的材料。在恒负载（200 MPa）条件下，研究了80 μm NiTi细丝的热循环性能。特别研究了阶梯电流脉冲和斜坡电流脉冲两种加热条件对SMA功能疲劳的影响。利用实验装置，对SM细丝的恢复应变、不可逆应变、特征温度和AT的变化及趋势进行了热循环、恒载热回路和驱动时间（AT）试验。
Shape memory alloys (SMA) are used in many technological applications, thanks to their unique properties: superelasticity and shape memory (SM) effect. Many efforts have been made to improve performance of SMA wires to utilize them as thermal actuators also for many thousands of cycles. Near-equiatomic nickel-titanium compound is the most used materials for SM actuators because of its high recoverable values of strain and good cycling stability, if compared to the other known SMA. In this study, the functional properties of NiTi thin wires (80 μm) thermally cycled under a constant load (200 MPa) were investigated. In particular, the effect of two heating conditions, carried out by a step and a ramp current pulses, on functional fatigue of SMA has been studied. By means of an experimental apparatus, thermomechanical cycling, thermal loop under constant load and actuation time (AT) tests were carried out to investigate the alteration and the trend of recovered strain, irreversible strain, characteristic temperatures, and ATs of the thin SM wires.