Creep deformation and rafting in nickel-based superalloys simulated by the phase-field method using classical flow and creep theories
Creep deformation and rafting in nickel-based superalloys simulated by the phase-field method using classical flow and creep theories
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DOI：
10.1016/j.actamat.2011.06.050
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发表时间：
2011-09
期刊：
影响因子：
9.4
通讯作者：
Yuhki Tsukada;Y. Murata;T. Koyama;N. Miura;Y. Kondo
中科院分区：
文献类型：
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作者：
Yuhki Tsukada;Y. Murata;T. Koyama;N. Miura;Y. Kondo
采用相场模型模拟了镍基高温合金高温蠕变过程中（γ+γ′）相组织和γ′相间非弹性应变（即γ通道）的演变。非弹性应变被定义为时间无关分量和时间相关分量之和。在非弹性应变演化计算中考虑了以前报道的单相γ合金的力学性能。采用二维相场法模拟了CMSX-4合金的高温蠕变过程，并将微观组织演化结果和蠕变速率-时间曲线与实验数据进行了拟合。模拟结果较好地再现了瞬态蠕变初始阶段蠕变速率-时间曲线的斜率、不同类型γ通道的塑性偏好以及筏化现象。此外，还证明了筏状组织形成后，γ/γ′界面处的蠕变速率局部增大。
A phase-field model has been developed to simulate the evolution of both (γ+γ′) microstructure and inelastic strain between γ′ phases (i.e. γ channel) during high-temperature creep in nickel-based superalloys. Inelastic strain is defined as the sum of time-independent and time-dependent components. Previously reported mechanical properties of single-phase γ alloys are considered in the calculation of inelastic strain evolution. A two-dimensional phase-field simulation is performed, and the results of microstructure evolution and the creep rate vs. time curve are fitted to the experimental data of the high-temperature creep of CMSX-4. The slope of the creep rate vs. time curve during the initial stage of transient creep, the plasticity preference in different types of γ channels, and the rafting phenomenon are reproduced well by the simulation. Furthermore, it is demonstrated that the creep rate increases locally at γ/γ′ interfaces when the rafted structure is formed.