Dupin Nathalie, Kattner Ursula R, Sundman Bo, Palumbo Mauro, Fries Suzana G
Calcul Thermodynamique, 63670 Orcet, France.
National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
J Res Natl Inst Stand Technol. 2018 Nov 26;123:1-33. doi: 10.6028/jres.123.020. eCollection 2018.
Most models currently used for complex phases in the calculation of phase diagrams (Calphad) method are based on the compound energy formalism. The way this formalism is presently used, however, is prone to poor extrapolation behavior in higher-order systems, especially when treating phases with complex crystal structures. In this paper, a partition of the Gibbs energy into effective bond energies, without changing its configurational entropy expression, is proposed, thereby remarkably improving the extrapolation behavior. The proposed model allows the use of as many sublattices as there are occupied Wyckoff sites and has great potential for reducing the number of necessary parameters, thus allowing shorter computational time. Examples for face centered cubic (fcc) ordering and the phase are given.
目前在相图计算（Calphad）方法中用于复杂相的大多数模型都是基于化合物能量形式体系。然而，这种形式体系目前的使用方式在高阶系统中容易出现外推行为不佳的情况，特别是在处理具有复杂晶体结构的相时。本文提出了一种将吉布斯自由能划分为有效键能的方法，而不改变其构型熵表达式，从而显著改善了外推行为。所提出的模型允许使用与被占据的魏科夫位置数量相同的子晶格，并且在减少必要参数数量方面具有很大潜力，从而可以缩短计算时间。给出了面心立方（fcc）有序化和 相的示例。
