Thermophysical Properties of Al-Si-Mg-Cu melts

在这个项目中，热物理性能，相关的理解和定量预测凝固，是实验确定的Al-Si-Mg-Cu合金系统。这些性质是液相的密度、粘度和表面张力。它们将作为温度和成分的函数进行测量，精度优于5%，并通过应用现有模型或开发新的适当模型与热力学势相关联。将特别注意确定最重要的过量数量，以确保导出的数据集的预测能力。为了提供尽可能高精度的测量数据，将采用电磁悬浮的无容器方法测量密度和表面张力。对于粘度测量，将使用新建的振荡杯粘度计。热物理和热力学数据之间的联系可以通过不同的模型来建立，例如巴特勒的表面张力方程，或Kaptay的粘度理论。通过这种方式，可以关闭使用CALPHAD型方法的热力学计算与热物理性质数据之间的循环，从而实现数据的迭代优化。

In this project, thermophysical properties, relevant for understanding and quantitatively predicting solidification, are to be determined experimentally for the Al-Si-Mg-Cu alloy system. These properties are density, viscosity, and surface tension of the liquid phase. They will be measured as a function of temperature and composition to an accuracy better than 5% and linked to thermodynamic potentials by applying existing models or by developing new, appropriate ones. Special attention will be paid to the determination of excess quantities which are of paramount importance, in order to ensure the predictive power of the derived data sets. To provide for the highest possible accuracy of the measured data, containerless methods using electromagnetic levitation will be employed for the measurement of density and surface tension. For viscosity measurements, a newly built oscillating cup viscometer will be used. A link between thermophysical and thermodynamic data can be established through different models, e.g. Butler’s equation for the surface tension, or Kaptay’s theory for the viscosity. This way, the loop between thermodynamic calculations, using a CALPHAD-type approach, and thermophysical property data can be closed, enabling an iterative optimization of the data.