在航空发动机等关键部件中，高温合金的性能及稳定性直接影响部件的安全性和效率。 通过对完全热处理后的 DD10 单晶高温合金在 700 和 1 100 ℃下进行长时热暴露实验，系统探究不同时效温度及时效时间下，合金中 γ′强化相(尺寸、形态、分布)与拓扑密排相(TCP 相)的体积分数、形貌特征及演化规律。结果表明，700 ℃热暴露过程中枝晶干和枝晶间的 γ′相均只产生了轻微粗化，并未发现有 TCP 相的析出。 随着热暴露温度的升高至 1 100 ℃，合金中 γ′相的形态发生了显著变化，1 100 ℃下热暴露 200 h 后，γ′相形貌由规则的立方态变成了不规则形态，形成了筏状组织。 随热暴露时间的延长，筏化组织逐渐粗化。 此外，随着温度升高，难熔元素的偏聚导致 μ 相的析出。 在 700 和 1 100 ℃热暴露过程中，温度越高 γ/γ′两相的晶格常数差值越小，两相错配度的绝对值也随之减小。 700 ℃热暴露 200 h 后的错配度略高于热处理态，此时 γ′相的立方度也达到最高。

In critical components such as aircraft engines, the performance and stability of high-temperature alloys directlyimpact component safety and efficiency. Through long-term thermal exposure experiments conducted at 700 and 1 100 ℃on fully heat-treated DD10 single-crystal superalloys, this study systematically investigated the volume fraction,morphological characteristics, and evolution mechanisms of the γ′ strengthening phase (size, morphology, distribution) andtopologically close-packed (TCP) phases under different aging temperatures and durations. The results indicate that during700 ℃ thermal exposure, only slight coarsening of the γ′ phase occurs along the dendrite trunks and interdendritic regions,with no TCP phase precipitation detected. As the thermal exposure temperature increases to 1 100 ℃, the morphology ofthe γ′ phase in the alloy significantly changes. After 200 h of thermal exposure at 1 100 ℃, the γ′ phase morphologytransforms from a regular cubic configuration to an irregular form, resulting in the formation of a rafted structure. Withprolonged thermal exposure time, the rafted structure gradually coarsens. Additionally, with increasing temperature, thesegregation of refractory elements induces the precipitation of the μ phase. During thermal exposure at 700 and 1 100 ℃,the difference in the lattice constant between the γ and γ′ phases decreases with increasing temperature, and the absolutevalue of the degree of misfit between the two phases also diminishes accordingly. After 200 h of thermal exposure at700 ℃, the degree of misfit is slightly greater than that in the as-heat-treated state, and the cubicity of the γ′ phase reachesits maximum at this point.