| About this Abstract |
| Meeting |
Materials Science & Technology 2019
|
| Symposium
|
Sandphobic Thermal/Environmental Barrier Coatings
|
| Presentation Title |
Effects of Silicate Melt Chemistry on Thermochemical Interactions with Thermal Barrier Oxides |
| Author(s) |
Najeb M. Abdul-Jabbar, Paul Kuhn, Sarah M Miller, Carlos G Levi |
| On-Site Speaker (Planned) |
Najeb M. Abdul-Jabbar |
| Abstract Scope |
Thermochemical interactions between silicate melts and thermal barrier oxides are a crucial component in developing strategies to alleviate environmental degradation of thermal/environmental barrier coatings (T/EBCs) in gas turbine engines. Generally, the crystallization of a rapid-growing apatite silicate in these reactions has proven to be an effective a barrier against subsequent melt infiltration in coating microstructures. In this investigation, the effects of melt chemistry on interactions between yttrium zirconate and molten silicates are examined. Equilibrium experiments reveal that subtle variations in iron and aluminum contents in the silicate melt can diminish the proclivity for apatite formation in favor of a slower-growing garnet phase, which reduces resistance to melt attack via thermochemical routes. This in turn demonstrates the influence of environmental chemistry on coating lifetimes and provides valuable insight into the design of more robust next-generation T/EBC systems. |