This study elucidates the influence of Nb addition on the mechanical and actuation response of the (Ni_49.5Ti_35.5Hf₁₅)₉₀Nb₁₀ high temperature shape memory alloy (HTSMA) wires and presents the microstructure evolution of Nb with the drawing process. The change in morphology of β-Nb from network structure to nanowires greatly increases the yield strength of the NiTiHfNb alloy followed by an ascending stress plateau. The fatigue life of the (Ni_49.5Ti_35.5Hf₁₅)₉₀Nb₁₀ wire is 7754 cycles with remarkably stable actuation strain of 2.3% under 418 MPa. The concept of in-situ nanowire composite is applied to HTSMAs for the first time and our finding implies the promising practical applications of NiTiHfNb wires in high temperature actuators.

本研究阐明了添加 Nb 对 (Ni _49.5 Ti _35.5 Hf ₁₅ ) ₉₀ Nb ₁₀高温形状记忆合金 (HTSMA) 线材的机械和驱动响应的影响，并展示了 Nb 在拉拔过程中的微观结构演变。β-Nb 的形态从网络结构到纳米线的变化大大提高了 NiTiHfNb 合金的屈服强度，随后出现了上升的应力平台。(Ni _49.5 Ti _35.5 Hf ₁₅ ) ₉₀ Nb _10线材的疲劳寿命为7754个循环，在418 MPa下具有2.3%的非常稳定的驱动应变。的概念原位纳米线复合材料首次应用于 HTSMA，我们的发现意味着 NiTiHfNb 线在高温执行器中的实际应用前景广阔。