Nitinol (NiTi), a shape memory alloy (SMA) of nickel and titanium, exhibits two unique properties: the shape memory effect and superelasticity. It is a material of choice for applications demanding extraordinary flexibility and motion. It is subjected to greater fatigue strains compared to ordinary metals. The structural and functional fatigue properties are important for assessing the fatigue life and reliability of the superelastic NiTi. The advances made in the experimental analysis to improve the structural and functional fatigue resistance of superelastic NiTi are reviewed in this paper. Various aspects of fatigue behaviour of NiTi in biomedical and cooling applications, along with fatigue failure mechanism, are elaborated under structural fatigue. Importance of functional fatigue and its connect with structural fatigue performance of NiTi is discussed citing recent research literature. Furthermore, the effect of processing parameters involved in additive manufacturing on the fatigue performance of NiTi is also discussed.

镍钛诺 (NiTi) 是一种镍和钛的形状记忆合金 (SMA)，具有两种独特的特性：形状记忆效应和超弹性。它是需要非凡灵活性和运动性的应用的首选材料。与普通金属相比，它承受更大的疲劳应变。结构和功能疲劳特性对于评估超弹性 NiTi 的疲劳寿命和可靠性很重要。本文综述了在提高超弹性 NiTi 结构和功能疲劳强度的实验分析中取得的进展。在结构疲劳下详细阐述了 NiTi 在生物医学和冷却应用中的疲劳行为的各个方面，以及疲劳失效机制。引用最近的研究文献讨论了功能疲劳的重要性及其与 NiTi 结构疲劳性能的联系。此外，还讨论了增材制造中涉及的加工参数对 NiTi 疲劳性能的影响。