论文标题
使用升级的Pycalphad和ESPEI在NB-NI系统中具有不确定性定量的热力学建模
Thermodynamic modeling with uncertainty quantification in the Nb-Ni system using the upgraded PyCalphad and ESPEI
论文作者
论文摘要
NB-NI系统已通过使用当前升级的Pycalphad和ESPEI的软件工具来重塑不确定性定量（UQ），这些软件工具包含新的能力，以建模Wyckoff位置的现场占用位置，以实现关注的阶段。具体而言，五个公共模型分别用于对μ-NB7NI6和δ-nbNi3的拓扑关闭包（TCP）阶段进行建模。基于calphad的建模的输入包括基于密度功能理论（DFT）的第一原理和声子计算的当前预测的热化学数据，以及文献中的相位平衡和现场占用数据。除了相图和热力学特性外，目前对现场占用率的calphad预测也与实验数据（例如μ-NB7NI6中测得的NB位点）很好地一致。此外，ESPEI中实现的Markov Chain Monte Carlo（MCMC）方法的预测UQ值使得可以量化NB-NI系统中的不确定性，例如μ-NB7NI6中的位点占用率和液体中混合的焓。
The Nb-Ni system has been remodeled with uncertainty quantification (UQ) by using the presently upgraded software tools of PyCalphad and ESPEI that contain the new capability to model site occupancy of Wyckoff position for the phases of interest. Specifically, the five- and three-sublattice models are used to model the topologically close pack (TCP) phases of μ-Nb7Ni6 and δ-NbNi3, respectively, according to exactly their Wyckoff positions; where the inputs for CALPHAD-based modeling include the presently predicted thermochemical data as a function of temperature by density functional theory (DFT) based first-principles and phonon calculations together with both phase equilibrium and site occupancy data in the literature. Besides phase diagram and thermodynamic properties, the present CALPHAD predictions of site occupancies are also agreed well with experimental data such as the measured Nb sites in μ-Nb7Ni6. In addition, the predicted UQ values using the Markov Chain Monte Carlo (MCMC) method as implemented in ESPEI make it possible to quantify uncertainties in the Nb-Ni system, such as site occupancies in μ-Nb7Ni6 and enthalpy of mixing in liquid.
