About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Materials Under Extreme Environment
|
| Presentation Title |
High Temperature Ablation of Pressureless Sintered HfC-SiC-TaC Ceramics |
| Author(s) |
Naomy L. Serrano, Lucia Ruiz, Caden Doolittle, David Burk, Anindya Ghoshal, Scott Walck, Lionel Vargas-Gonnzalez, Rick Reidy, Marcus Young, Andrey Voevodin, Samir Aouadi |
| On-Site Speaker (Planned) |
Naomy L. Serrano |
| Abstract Scope |
This study examined the effects of TaC additions on HfC-SiC composites fabricated through pressureless sintering. The addition of TaC significantly enhanced densification, hardness, and flexural strength. Hardness values increased from 13.0 ± 1.7 GPa to 18.0 ± 2.1 GPa while flexural strength values were enhanced from 303 ± 30 to 395 ± 23 MPa. Scanning and transmission electron microscopy analysis of the protective oxide layer on post ablation samples revealed that the addition of 20 wt.% TaC resulted in formation of Ta₂C particles, with an average grain size in the 10-50 nm range, embedded in a matrix consisting of interlaced Hf-rich and Si-rich amorphous regions. Near the surface, the Ta₂C particles oxidized and dissolved into the Hf-rich region. The protective oxide phase that formed consisted of an interwoven matrix of HfSiO₄ and Hf₆Ta₂O₁₇. This interwoven matrix oxide formation was correlated to the observed improvement in the ablation resistance. |