This study concerns the substitution of copper for nickel in the Ni–Ti system in order to obtain a molar ratio of Ni₄₀Ti₅₀Cu₁₀. Effects of preheating temperature were studied to understand the morphology, phase transformation, and microstructure of the samples by using self-propagating high-temperature synthesis. Therefore, three distinct preheating temperatures (230 °C, 320 °C, and 410 °C) were used for the study. The thermochemical calculations performed with FactSage presented similar results with the experimental data in terms of solid–liquid ratios and adiabatic temperature during the reactions. An increase in the preheating temperature very slightly changed the transformation temperature, but it was shown to be insignificant. B2 crystal structure was found as the main phase besides a small amount of martensite, Ti₂Ni(Cu), and Ni(Cu)₂Ti–Ni(Cu)₃Ti by various characterization methods. The monoclinic twinned martensitic (B19′) structure was encountered in transmission electron microscopy analyses.

Graphical abstract

中文翻译：

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自蔓延燃烧法合成Ni40Ti50Cu10金属间形状记忆合金及其显微组织

本研究涉及在 Ni-Ti 体系中用铜代替镍，以获得 Ni ₄₀ Ti ₅₀ Cu _{10的摩尔比}. 通过自蔓延高温合成研究了预热温度的影响，以了解样品的形貌、相变和微观结构。因此，研究中使用了三个不同的预热温度（230 °C、320 °C 和 410 °C）。使用 FactSage 进行的热化学计算在反应过程中的固液比和绝热温度方面呈现出与实验数据相似的结果。预热温度的增加非常轻微地改变了转变温度，但它被证明是微不足道的。除少量马氏体、Ti ₂ Ni(Cu)和Ni(Cu) ₂ Ti-Ni(Cu) _{3外，B2晶体结构为主相}Ti通过各种表征方法。在透射电子显微镜分析中遇到了单斜孪晶马氏体 (B19') 结构。

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