Thermodynamic evaluation of the Al-Si-Mg-Cu phase diagram, including molar volumes

该项目的总体目标，如最初的提议所述，仍然是利用CALPHAD方法开发出对整个Al-Si-Mg-Cu四元系的准确和可靠的热力学描述。随着我们在这个捆绑项目中的合作伙伴从集中的实验研究和从头计算中输入数据，热力学描述的质量将有可能达到一个新的水平。在本项目拟议的第二阶段，我们计划将我们的工作重点放在铜-硅和铝-铜-硅系统的建模上，以及四元Q相的热力学模型上。模拟将基于“热化学和组成性质”(TUC)和“临界凝固实验”(FSU)项目的新实验数据，以及来自“热力学数据从头算预测”(MPIE)项目的从头计算。在从头计算数据的基础上，建立了fcc-Al热空位模型。“铝-硅-镁-铜熔体的热物理性质”(DLR)项目中的液态密度测量将用于对整个体系的摩尔体积进行建模，从而能够进行与压力相关的计算以及计算凝固和冷却过程中的体积变化。

The global goal of this project, as laid out in the initial proposal, remains the development of an accurate and reliable thermodynamic description of the entire quaternary Al-Si-Mg-Cu system using the Calphad method. With the input of data from focused experimental investigations and ab initio calculations from our partners in this bundled project it will be possible to reach a new level of quality of the thermodynamic description. In the proposed second period of this project we plan to focus our work on the modeling of the Cu-Si and Al-Cu-Si systems, and on a thermodynamic model for the quaternary Q-phase. The modeling will be based on new experimental data from the projects “Thermochemical and constitutional properties” (TUC) and “Critical solidification experiments” (FSU) and on ab initio calculations from the project “Ab initio prediction of thermodynamic data” (MPIE). Based on the ab initio data a model for thermal vacancies in fcc-Al will be developed. Density measurements of the liquid phase from the project “Thermophysical properties of Al-Si-Mg-Cu melts” (DLR) will be used to model molar volumes of the entire systems, so enabling pressure dependent calculations and calculation of volume changes during solidification and cooling.