About this Abstract |
| Meeting |
2022 TMS Annual Meeting & Exhibition
|
| Symposium
|
Refractory Metals
|
| Presentation Title |
Effect of Heating Rate and Substrate on the Oxidation Behavior of Hafnium Aluminum Diboride Thin Films |
| Author(s) |
Samyukta Shrivastav, Dana Yun, Carly Romnes, Kinsey Canova, John R Abelson, Jessica Krogstad |
| On-Site Speaker (Planned) |
Samyukta Shrivastav |
| Abstract Scope |
The oxidation resistance of hafnium diboride in high temperature applications is attributed to a liquid boria phase, which can be volatile depending on temperature and pressure. This volatility poses a problem for thin films, as it may lead to spallation and consumption of the film. Here, aluminum is alloyed with hafnium diboride via a low-temperature CVD process to enable the formation of a protective aluminum oxide and suppress boria volatilization. We show that the oxidation behavior of HfAlBx thin films is strongly dependent on heating rate and substrate interaction. The thickness, phase, and composition of the oxide formed were determined using HRTEM and SEM. In cases that did not develop a continuous passivating oxide, complete oxidation of films was observed. Films on sapphire gave rise to the formation of nano-whiskers of Al4B2O9 with traces of alumina, while films deposited on silicon resulted in the formation of an amorphous silica layer |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Temperature Materials, Thin Films and Interfaces, Characterization |