| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
ACerS Robert B. Sosman Award Symposium: Advancing the Science of Materials for Extreme Environments
|
| Presentation Title |
Effects of Liquid and Gas Phase Formation on Mechanisms of Ultra-high Temperature Ceramic Oxidation |
| Author(s) |
Lavina Backman, Connor J. Stephens, Elizabeth J. Opila |
| On-Site Speaker (Planned) |
Elizabeth J. Opila |
| Abstract Scope |
Ultra-high temperature ceramics (UHTCs) such as group IV, V, and VI transition metal carbides and borides are proposed for use as hypersonic vehicle leading edges due to their high melting temperatures. Unfortunately, their oxidation rates are rapid. The recent “high entropy” (HE) materials design approach has been applied to UHTCs and found to yield improved mechanical properties, but increased degradation by oxidation due to formation of low melting oxide eutectics. The HE carbides performed worse than the borides. The poor performance of carbides is often attributed to the generation of CO(g) during oxidation that promotes the formation of porous oxide scales. However, there are no known studies that compare the oxidation of transition metal carbides to the oxidation of corresponding transition metals. In this presentation, the complexities of oxidation mechanisms in cases where liquid and gaseous products form are discussed with recommendations for design of UHTCs with improved oxidation resistance. |