Abstract The ageing effects on the microstructure, martensitic transformation and shape memory performance of a Ni-rich Ti49.5Ni34.5Cu11.5Pd4.5 alloy as a function of temperature were investigated. The formation of (Ni,Cu)2Ti-type precipitated phases arises from the ageing treatment. When ageing at 500 °C, the fine precipitated phases are diffusely distributed, which improves the shape memory performance efficiently. With the tensile deformation of 5%, the 500 °C aged specimen shows a 25% larger strain recovery rate (a maximum value of 96.8%) than that of the specimen under solution treatment. And after 100 thermal cycles, the transformation temperature variation is lesser than 0.2 °C in the specimen aged at 500 °C. There presents excellent thermal cycling stability while keeping near-zero thermal hysteresis.

中文翻译：

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时效对富镍Ti49.5Ni34.5Cu11.5Pd4.5合金组织、马氏体转变和形状记忆性能的影响

摘要 研究了时效对富Ni Ti49.5Ni34.5Cu11.5Pd4.5合金显微组织、马氏体转变和形状记忆性能随温度的影响。(Ni,Cu)2Ti 型沉淀相的形成源于时效处理。当在 500°C 时效时，细小的析出相扩散分布，有效地提高了形状记忆性能。拉伸变形为 5% 时，500 °C 时效试样的应变恢复率（最大值为 96.8%）比固溶处理试样大 25%。并且在100次热循环后，在500℃时效的试样中转变温度变化小于0.2℃。在保持接近零的热滞后的同时呈现出优异的热循环稳定性。