Thermophysical Properties of Al-Si-Mg-Cu melts
Final Report Abstract
The overall goal of our project is to produce a reliable and consistent set of thermophysical property data for liquid alloys of the Al-Si-Mg-Cu system. In particular, it is intended to determine experimentally density, viscosity, and surface tension as functions of temperature and composition with high accuracy. The investigation of this material class is very challenging, because of the high reactivity of liquid Al and Si and their affinity to oxygen as well as the high vapor pressure of Mg. For these reasons, our work on liquid Al-Mg-Si-Cu had to be focused on its binary subsystems and on the ternary Al-Cu-Si subsystem and the planned measurement on Al-Mg-Si and Al- Cu-Si-Mg had to be further postponed in favor of the generation of reliable data. In the first funding phase, we measured viscosities of Al-Cu, densities of binary Al-Si and densities of the ternary system Al-Cu-Si. In addition, density was measured of a binary Al-Mg alloy. The data produced this way has already found entrance in reference data bases and enabled the group of Dr. Bengt Hallstedt (RWTH) to include the pressure dependence of the Gibbs free energy in thermodynamic modeling. In the second funding phase, the density measurements on Al-Cu-Si, started during the first period of funding, were completed. Then, viscosity was measured on this system. The viscosity data of binary Al-Cu and ternary Al-Cu-Si alloys has been compared to existing thermodynamic models, namely the Kaptay 16 and the Hirai 17 model. We also developed our own model. In combination with our earlier investigations on Al-Cu the addressed thermophysical properties are now entirely covered by measurements of our group. The measurement of surface tension of Al-Si turned out to be a major challenge due high affinity of both elements with oxygen. Controlling the oxygen partial pressure in the processing environment, allowed us to determine accurate data for the pure elements Al and Si and to study the role of adsorbed oxygen on the surface of the liquid Al-Si alloy.
Publications
- J. Phys. Chem. Ref. Data 41 (2012) 033103-1
M. Assael, E. K. Mikhailidou, J. Brillo, S. V. Stankus, J. T. Wu, W. A Wakeham
- J. Mater. Sci. 47 (2012) 3706
- J. Mater. Sci. 47 (2012) 8145
M. Schick, J. Brillo, I. Egry, B. Hallstedt
- J. Mater. Sci. 49 (2014) 3541
H. Kobatake, J. Schmitz, J. Brillo
(See online at https://doi.org/10.1007/s10853-014-8072-z) - Phys. Chem. Liquids: An International Journal (2014) 1
A. Yakymovych, Yu. Plevachuk, S. Mudry, J. Brillo, H. Kobatake, H. Ipser
(See online at https://doi.org/10.1080/00319104.2013.876639) - J. Mater. Sci. 50 (2015) 3351
H. Kobatake, J. Brillo, J. Schmitz, P.-Y. Pichon
(See online at https://doi.org/10.1007/s10853-015-8883-6)
