| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Phase Transformations in Ceramics: Science and Applications
|
| Presentation Title |
In-situ Phase Equilibria in the TiO2-HfO2-WO3 System up to 1400˚C |
| Author(s) |
Benjamin Hulbert, Dylan Blake, Waltraud Kriven |
| On-Site Speaker (Planned) |
Benjamin Hulbert |
| Abstract Scope |
The TiO2-HfO2-WO3-temperature phase diagram was investigated up to 1400℃ in air with in-situ synchrotron powder diffraction. The high melting temperatures of these multi-component Ti-Hf-W-oxides and their applications as refractory structural materials and in high temperature electronics and sensors motivated this study. The temperatures required were reached with a quadrupole lamp furnace with powder samples mounted in fused-silica capillaries in air from 25℃ to 1200℃. Additionally, a 400W CO2 laser, with a conical nozzle levitator, heated solid spherical samples from 700℃ to 1400℃. Synchrotron data at ~50℃ intervals allowed determination of phase-fractions and crystal structures. Equilibrium phases were determined by checking the reversibility of phase transformations in XRD experiments. Temperature-dependent thermal expansions of all phases present were measured. Phase diagram development is vital in the ceramics industry, as engineers refer to them during the material selection process to ensure thermodynamic stability of the materials under the required conditions. |