An insight into using DFT data for Calphad modeling of solid phases in the third generation of Calphad databases, a case study for Al
An insight into using DFT data for Calphad modeling of solid phases in the third generation of Calphad databases, a case study for Al
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DOI：
10.1016/j.calphad.2019.02.008
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发表时间：
2019-06-01
影响因子：
2.4
通讯作者：
Selleby, Malin
中科院分区：
文献类型：
--
作者：
Bigdeli, Sedigheh;Zhu, Li-Fang;Selleby, Malin
在开发下一代 Calphad 数据库时，使用了新模型，其中贡献吉布斯能量的每个术语都具有物理意义。为了继续发展，目前的工作使用有限温度密度泛函理论 (DFT) 结果来讨论和建议最适用且基于物理的模型，用于对熔点以上固相进行 Calphad 评估（之前评估中对固相进行建模的断点）。这些结果用于研究固体在过热温度区域的特性，并用更基于物理的温度（即过热固体塌陷为液体的温度）代替作为断点的熔化温度。这种方法的优点和局限性通过对一元铝的新评估来呈现。
In developing the next generation of Calphad databases, new models are used in which each term contributing to the Gibbs energy has a physical meaning. To continue the development, finite temperature density-functionaltheory (DFT) results are used in the present work to discuss and suggest the most applicable and physically based model for Calphad assessments of solid phases above the melting point (the breakpoint for modeling the solid phase in previous assessments). These results are applied to investigate the properties of a solid in the superheated temperature region and to replace the melting temperature as the breakpoint with a more physically based temperature, i.e., where the superheated solid collapses into the liquid. The advantages and limitations of such an approach are presented in terms of a new assessment for unary aluminum.