A nanoindentation-based study is conducted to analyse the small-scale deformation behaviour of superelastic NiTi-based shape memory alloy. The mechanism is compared with respect to that for traditional elastic–plastic ferrous and non-ferrous alloys: ferritic stainless steel of grade 409 and Al. To develop a comprehensive insight into the deformation behaviour, various experiments including nanoindentation, optical microscopy, X-ray diffraction, differential scanning calorimetry are performed on all alloy systems. This detailed study demonstrates that structural properties are primarily controlled by the crystal structures of the phases present in the respective alloy systems. Among these three studied alloys, the highest and lowest nano-hardness is realized for the steel and Al, respectively. Intermediate hardness is noted for the NiTi alloy. Nevertheless, the localized deformation characteristics of the superelastic alloy appeared to be entirely different in relation to that for the ferrous and non-ferrous materials. Most importantly, a fourfold increment in the depth recovery is realized for the NiTi alloy in contrast to the traditional metallic system. To understand this exceptional recovery, detailed analysis is performed on the unloading response of all the alloys. The crucial role of reversible stress-induced martensitic transformation in contributing towards the depth recoverability for superelastic NiTi alloy is thereby revealed.

进行了基于纳米压痕的研究，以分析超弹性NiTi基形状记忆合金的小尺寸变形行为。将其机理与传统的弹塑性亚铁和有色合金：409级和Al的铁素体不锈钢进行了比较。为了全面了解变形行为，对所有合金系统进行了各种实验，包括纳米压痕，光学显微镜，X射线衍射，差示扫描量热法。这项详细的研究表明，结构性能主要受相应合金体系中存在的相的晶体结构控制。在这三种研究合金中，钢和铝分别实现了最高和最低的纳米硬度。NiTi合金的硬度中等。但是，超弹性合金的局部变形特性似乎与铁和非铁材料的完全不同。最重要的是，与传统的金属系统相比，NiTi合金在深度恢复方面实现了四倍的增量。为了理解这种异常的恢复，对所有合金的卸载响应进行了详细的分析。从而揭示了可逆应力诱发的马氏体相变在促进超弹性NiTi合金的深度可恢复性中的关键作用。与传统的金属系统相比，NiTi合金的深度恢复提高了四倍。为了理解这种异常的恢复，对所有合金的卸载响应进行了详细的分析。从而揭示了可逆应力诱发的马氏体相变在促进超弹性NiTi合金的深度可恢复性中的关键作用。与传统的金属系统相比，NiTi合金的深度恢复提高了四倍。为了理解这种异常的恢复，对所有合金的卸载响应进行了详细的分析。从而揭示了可逆应力诱发的马氏体相变在促进超弹性NiTi合金的深度可恢复性中的关键作用。