This paper investigates the evolutions of transformation temperatures and residual martensite of shape memory alloys during cyclic loading. Pseudoelastic NiTi specimens were firstly subjected to stress-controlled cyclic loading; then differential scanning calorimetry and x-ray diffraction characterizations were conducted on samples cut from specimens after different cycles as well as virgin one. Results show that (i) transformation temperatures rise while the transformation temperature hysteresis increases at initial cycles and then remarkably decreases when the SMA is highly distorted; (ii) due to the accumulation of residual martensite, the more fatigue cycles applied to the SMAs, the less latent heat absorbed/released during the transformation. Furthermore, residual martensite volume fraction was calculated with respect to plasticity and a linear character was observed.

中文翻译：

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形状记忆合金在循环加载过程中相变特性的演变：相变温度滞后和残余马氏体

本文研究了形状记忆合金在循环加载过程中相变温度和残余马氏体的演变。伪弹性NiTi试样首先受到应力控制的循环载荷；然后再进行试验。然后对从原始样品和不同原始样品切下的样品进行差示扫描量热法和X射线衍射表征。结果表明：（i）在初始循环中，转变温度升高而转变温度滞后增加，而当SMA高度变形时，转变温度显着下降；（ii）由于残余马氏体的积累，施加到SMA的疲劳循环越多，在转化过程中吸收/释放的潜热就越少。此外，