Abstract The morphological evolution and precipitation kinetics of γ′ and D019(Co3W) phase in Co–Al–W alloys at 900 °C have been studied by applying Phase-field method and experiment in order to understand the transformation process of γ′ phase and D019 phase. The growth processes of D019 phase and precipitation of γ′ phase under elastic fields were simulated through coupling with thermodynamics and dynamics databases. The simulation results indicate that the misfit δ ≥ 0.53% has a greater impact on γ′ particle morphology in γ/γ′ structure. Co–Al–W alloy with low Al and high W is one of the factors to promote the precipitation of D019 phase. Three stages during aging, namely the γ′ phase incubation stage, the γ′ phase fast nucleation and growth stage, and the transformation from γ′ phase to D019 phase stage can be observed with the non-constant coarsening rate that varying with the decrease of γ′ phase. The particle size distribution(PSD) during the precipitation of D019 phase is more in line with MLSW theory than LSW theory. This simulation results are in good agreement with the experiment results to help analyze microstructure evolution of Co–Al–W alloy.

中文翻译：

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Co-Al-W高温合金γ/γ'组织中D019相微观组织演化的相场模拟

摘要 采用相场法和实验研究了 Co-Al-W 合金中 γ' 和 D019(Co3W) 相在 900 °C 时的形态演变和析出动力学，以了解 γ' 相和 D019(Co3W)相的转变过程。 D019 阶段。结合热力学和动力学数据库，模拟了弹性场下D019相的生长过程和γ′相的析出过程。模拟结果表明，失配δ≥0.53%对γ/γ′结构中γ′粒子形貌的影响较大。低Al高W的Co-Al-W合金是促进D019相析出的因素之一。时效三个阶段，即γ'相孵化阶段，γ'相快速成核和生长阶段，可以观察到从γ'相到D019相阶段的转变，粗化率随γ'相的减少而变化。D019相析出过程中的粒度分布(PSD)比LSW理论更符合MLSW理论。该模拟结果与实验结果非常吻合，有助于分析 Co-Al-W 合金的微观结构演变。