|About this Abstract
||2020 TMS Annual Meeting & Exhibition
||Characterization of Minerals, Metals and Materials
||Thermodynamic Investigations at High Temperatures of the ZrO<sub>2</sub>-YTaO<sub>4</sub> Quasibinary for Thermal Barrier Coating Applications
||Maren Lepple, Sergey V Ushakov, Kristina Lilova, Chandra A Macauley, Carlos G Levi, Alexandra Navrotsky
|On-Site Speaker (Planned)
Compositions at the ZrO<sub>2</sub> rich and the YTaO<sub>4</sub> rich end of the ZrO<sub>2</sub>-YTaO<sub>4</sub> quasibinary have been proposed as candidate materials for next generation thermal barrier coatings owing to their attractive high temperature properties. For high temperature applications, it is essential to have a rigorous understanding of the materials system, including phase stabilities and relations as well as quantification of the energies and driving forces for forming the stable and metastable phases. However, investigations of high temperature phase stable materials require measurement temperatures > 1500 °C leading to experimental challenges, such as severe side reactions or temperature limits of the equipment. In this work, transition temperatures, enthalpies and phase stabilities in the ZrO<sub>2</sub>-YTaO<sub>4</sub> quasibinary were explored by several thermal analysis techniques, e.g. differential thermal analysis, drop-and-catch calorimetry and in-situ X-ray diffraction. The results will be used for CALPHAD modeling to obtain a self-consistent thermodynamic database and comprehensive understanding of the quasibinary.