Shape memory alloy undergoing reversible martensitic transformation is an important class of metallic functional materials. In the past two decades, the development of shape memory alloys enables great advances in biomedical devices, microelectronics, and energy conversions. As the application scales of these devices get smaller and smaller, it is very critical to understand and tune the mechanical properties of shape memory alloys in nanoscale regime. While there are extensive reviews of shape memory alloys regarding their macroscopic properties, metallurgical treatments, and applications in the design of microdevices, their nanomechanics are not well summarized and thoroughly compared transversely among different experimental setups. This review provides an insight of the latest discoveries in nanomechanics of NiTi-based and Cu-based shape memory alloys, which sorts out the size effects, the deformation mechanisms, and the functional fatigue of the miniaturized samples in single-crystalline and polycrystalline formats.

经历可逆马氏体相变的形状记忆合金是一类重要的金属功能材料。在过去的二十年中，形状记忆合金的发展推动了生物医学设备，微电子学和能量转换领域的巨大进步。随着这些设备的应用规模越来越小，理解和调整纳米级形状记忆合金的机械性能非常关键。尽管对形状记忆合金的宏观性能，冶金处理及其在微器件设计中的应用进行了广泛的评论，但它们的纳米力学尚未得到很好的总结，并且在不同的实验装置之间进行了横向比较。