Scholarlink

<p>The minimization of stress hysteresis in shape memory alloys (SMAs) is crucial for enhancing device sensitivity and control precision. This study investigates the grain size effect on the stress hysteresis of nanocrystalline TiNiFe SMAs produced through drawing and annealing. Our findings reveal that the stress–strain curves of these alloys exhibit pronounced stress plateaus, with the stress hysteresis of martensitic transformation diminishing as grain size decreases. Notably, at a grain size of 15&#xa0;nm, the stress hysteresis is significantly reduced to 232&#xa0;MPa. Tensile testing demonstrated that decreasing grain size significantly increases the martensitic phase yield strength of nanocrystalline NiTiFe while simultaneously reducing the residual strain after stress-induced martensitic transformation. We attribute this concurrent reduction in stress hysteresis to the elevated yield strength of finer-grained NiTiFe SMAs. The higher yield strength suppresses plastic deformation during stress accommodation and diminishing elastic strain energy dissipation and consequently lowering the stress hysteresis. Furthermore, the decreased twin spacing within single variant martensite, which shortens the phase boundary movement distance and reduces frictional energy, may also contribute to reducing the stress hysteresis.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Effect of Grain Size on the Stress Hysteresis of Martensitic Transformation in Nanocrystalline NiTiFe Shape Memory Alloy

  • 期刊论文

  • 发表日期：

    2026年6月2日

查看全文
  • Cuihong Sheng,
  • Yufei Tang,
  • Pengfei Zhang,
  • Chengyu Fu,
  • Yapeng Li,
  • Zhongni Liao,
  • Taotao Wang

摘要

The minimization of stress hysteresis in shape memory alloys (SMAs) is crucial for enhancing device sensitivity and control precision. This study investigates the grain size effect on the stress hysteresis of nanocrystalline TiNiFe SMAs produced through drawing and annealing. Our findings reveal that the stress–strain curves of these alloys exhibit pronounced stress plateaus, with the stress hysteresis of martensitic transformation diminishing as grain size decreases. Notably, at a grain size of 15 nm, the stress hysteresis is significantly reduced to 232 MPa. Tensile testing demonstrated that decreasing grain size significantly increases the martensitic phase yield strength of nanocrystalline NiTiFe while simultaneously reducing the residual strain after stress-induced martensitic transformation. We attribute this concurrent reduction in stress hysteresis to the elevated yield strength of finer-grained NiTiFe SMAs. The higher yield strength suppresses plastic deformation during stress accommodation and diminishing elastic strain energy dissipation and consequently lowering the stress hysteresis. Furthermore, the decreased twin spacing within single variant martensite, which shortens the phase boundary movement distance and reduces frictional energy, may also contribute to reducing the stress hysteresis.