| About this Abstract |
| Meeting |
MS&T23: Materials Science & Technology
|
| Symposium
|
Phase Transformations in Ceramics: Science and Applications
|
| Presentation Title |
Enhancing Oxidation Resistance of Silicon Nitride Using Ca2+ Stabilizer |
| Author(s) |
Prapassorn Numkiatsakul, Waltraud M. Kriven, Tonghun Lee, Kenneth S. Kim, Chol-Bum M. Kweon |
| On-Site Speaker (Planned) |
Prapassorn Numkiatsakul |
| Abstract Scope |
Silicon nitrides are widely used in ceramic heaters for combustion engines due to their high strength and wear resistance. However, their poor oxidation resistance at elevated temperatures limits their reliability. Oxidation products, such as silicon dioxide and intermediate compounds from sintering additives, often suffer from microcracks due to phase transformation during thermo-mechanical cycles. One potential solution is to use stuffing cations to chemically stabilize the transformation of the oxidation front. This study investigated the effect of Ca2+ stuffing ions on Si3N4 with MgO and Y2O3 sintering aids. The Si3N4 samples were coated with CaO; the phase composition, microstructure, and chemical distribution of the oxidation products were analyzed using XRD, SEM, and EDS. The oxidation coupon tests revealed that the CaO coating effectively protected Si3N4 from oxidation at 1300 ºC for 50h. Moreover, the microstructure analysis showed that the CaO coating could significantly reduce the oxidation thickness of Si3N4 samples. |