发表机构
The Ohio State University（俄亥俄州立大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出一种相场建模策略，通过定义内部热力学变量并采用Allen-Cahn弛豫方程，将CALPHAD液相模型纳入相场模拟，以预测液体中有序化导致的微观结构演化。
AI 中文摘要
混合的强负焓可导致液体溶液中的有序化。为了描述液体中的有序化，CALPHAD方法中已开发了不同的液相热力学描述，包括缔合物模型和修正的准化学模型。在本研究中，我们表明，在相场模拟中直接纳入这些液相模型及其相应的CALPHAD型自由能公式的关键，在于识别内部过程并正确定义内部热力学变量。液相的自由能随后可转化为组分组成和内部变量的函数，而内部变量的演化将通过Allen-Cahn型弛豫方程确定。我们利用Na-Sb和Na-Sn体系中从液相形成化学计量相的过程来演示这一建模策略。这项研究将为使用相场模拟预测具有有序化的液体中微观结构演化铺平道路。
英文摘要
A strong negative enthalpy of mixing can lead to ordering in liquid solutions. To describe ordering in liquids, different thermodynamic descriptions of liquid phases have been developed in the CALPHAD approach, including the associate model and the modified quasichemical model. In this study, we show that the key to directly incorporate these liquid phase models and their corresponding CALPHAD-type free energy formulations in phase-field simulations, is to identify the internal processes and to properly define the internal thermodynamic variables. The free energy of the liquid phase can then be converted to a function of component compositions and internal variables, and the evolution of the internal variables will be determined via Allen-Cahn-type relaxation equations. We demonstrate this modeling strategy using the formation of stoichiometric phases from liquid phases in Na-Sb and Na-Sn systems. This study will pave the way for predicting microstructure evolution in liquids with ordering using phase-field simulations.
