Thermophysical properties of liquid Al-Ti-V alloys measured by electromagnetic levitation

Abstract

Titanium based alloys are used in a wide variety of high-performance applications like aviation, medical technology or in the maritime sector, due to their combination of excellent mechanical properties and corrosion resistance. Recently, interest in these alloys for the use in combination with new manufacturing routes, such as additive manufacturing has increased drastically. Precise knowledge of the thermophysical properties of the used alloys is a basic requirement for a target-oriented design and modelling of such manufacturing processes. This work aims to provide a systemetical and reliable data foundation for the liquid Al-Ti-V alloy system as well as to provide different modelling methods to predict the density and surface tension depending on temperature and composition. This data foundation helps to develop a deeper understanding of the fundamental mixing mechanisms in the ternary system. The current study is the logical successor of our previous research on the liquid binary sub-system Al-Ti, Ti-V, and Al-V with the aim of a systematic investigation of the thermophysical properties for the Al-Ti-V system. In this work, liquid density and surface tension is measured for different alloy compositions along the AlxTi05(1-x)V05(1-x) section through the ternary Al-Ti-V system. The contact-less measurement methods optical dilatometry and oscillating drop technique are used in combination with the containerles electromagnetic levitation technique. By these means, contamination can be avoided and a wide temperaturwe range becomes acessible for the high melting, highly reactive alloy system. Different alloy compositions are investigated over these wide temperature ranges to determine both the temperature dependence and the compositional dependence of the density and the surface tension. Different thermodyamic models, predicting liquid density and surface tension for the alloy system are compared against the experimentally obtained data. It is investigated if a ternary interaction contribution needs to be considered when developing such models.