Sundman Bo, Kattner Ursula R, Hillert Mats, Selleby Malin, Ågren John, Bigdeli Sedigheh, Chen Qing, Dinsdale Alan, Hallstedt Bengt, Khvan Alexandra, Mao Huahai, Otis Richard
OpenCalphad, 9 Allée de l'Acerma, 91190 Gif sur Yvette, France.
Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8555, Gaithersburg, MD 20899, USA.
CALPHAD. 2020;68. doi: 10.1016/j.calphad.2020.101737.
Thermodynamic descriptions in databases for applications in computational thermodynamics require representation of the Gibbs energy of stable as well as metastable phases of the pure elements as a basis to model multi-component systems. In the Calphad methodology these representations are usually based on physical models. Reasonable behavior of the thermodynamic properties of phases extrapolated far outside their stable ranges is necessary in order to avoid that they become stable just because these properties extrapolate badly. This paper proposes a method to prevent crystalline solid phases in multi-component systems to become stable again when extrapolated to temperatures far above their melting temperature.
用于计算热力学应用的数据库中的热力学描述需要将纯元素的稳定相和亚稳相的吉布斯自由能表示出来，作为对多组分系统进行建模的基础。在相图计算（Calphad）方法中，这些表示通常基于物理模型。为了避免相的热力学性质仅仅因为外推效果不佳而变得稳定，需要使相的热力学性质在远远超出其稳定范围时仍具有合理的行为。本文提出了一种方法，以防止多组分系统中的结晶固相在外推到远高于其熔点温度时再次变得稳定。
