Application of a multi-component mean field model to the coarsening behaviour of a nickel-based superalloy
Application of a multi-component mean field model to the coarsening behaviour of a nickel-based superalloy
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DOI：
10.1016/j.actamat.2016.05.024
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发表时间：
2016-08
期刊：
影响因子：
9.4
通讯作者：
M. Anderson;A. Rowe;J. Wells;H. Basoalto
中科院分区：
文献类型：
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作者：
M. Anderson;A. Rowe;J. Wells;H. Basoalto
采用多组分平均场模型预测了镍基高温合金IN 738 LC中γ′相的颗粒演化，捕捉了γ ′相从初始多峰分布向单峰分布的转变过程。利用显微照片的定量分析，对等温热处理过程中的粗化行为进行了实验测量。γ′粒子的三维尺寸已被近似用于模拟。一个耦合的热力学/平均场建模框架，并应用于描述颗粒尺寸的演变。一个强大的数值实现模型的详细说明，利用代理模型来捕获的热力学。非稀相粒子系统的粒子增长速率的不同描述已经被探索。通过数值模拟研究了化学成分分散对颗粒尺寸分布演化的影响。它示出了给定合金的化学成分的公差如何影响颗粒粗化行为。这种预测能力对于理解部件性能的变化和化学成分公差的细化是有意义的。已经发现，在当前的模型公式中包含失配应变对预测的长期颗粒粗化行为没有显著影响。模型预测与实验数据吻合良好。特别是，该模型预测从双峰到单峰分布的过渡期间的平均粒径的增长率降低。
A multi-component mean field model has been applied to predict the particle evolution of the γ′ particles in the nickel based superalloy IN738LC, capturing the transition from an initial multimodal particle distribution towards a unimodal distribution. Experiments have been performed to measure the coarsening behaviour during isothermal heat treatments using quantitative analysis of micrographs. The three dimensional size of the γ′ particles has been approximated for use in simulation. A coupled thermodynamic/mean field modelling framework is presented and applied to describe the particle size evolution. A robust numerical implementation of the model is detailed that makes use of surrogate models to capture the thermodynamics. Different descriptions of the particle growth rate of non-dilute particle systems have been explored. A numerical investigation of the influence of scatter in chemical composition upon the particle size distribution evolution has been carried out. It is shown how the tolerance in chemical composition of a given alloy can impact particle coarsening behaviour. Such predictive capability is of interest in understanding variation in component performance and the refinement of chemical composition tolerances. It has been found that the inclusion of misfit strain within the current model formulation does not have a significant affect upon predicted long term particle coarsening behaviour. Model predictions show good agreement with experimental data. In particular, the model predicts a reduced growth rate of the mean particle size during the transition from bimodal to unimodal distributions.