About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Molecular Approaches to Ceramics; Synthesis, Processing, Modeling, and Derived Ceramics
|
| Presentation Title |
Use of Embedded Oxidation Marker Particles to Track Oxidant Ingress in Heterogeneous Microstructures Produced from Polymer Derived Ceramics |
| Author(s) |
David L. Poerschke, Colton Thomasson |
| On-Site Speaker (Planned) |
David L. Poerschke |
| Abstract Scope |
The implementation of SiC-based ceramic composites is limited by challenges processing high purity, defect-free matrices. Whereas dense SiC or Si3N4 matrices effectively prevent the oxidant ingress, matrix heterogeneity (porosity, composition, crystallinity, and grain size) can accelerate oxidant ingress and lead to premature component failure. This is particularly true in composites produced using polymer derived ceramics, wherein the final matrix may be amorphous or semi-crystalline, and typically contains pores and microcracks ranging from nanometers to tens of microns. Elucidating the oxidation mechanisms in such materials is critical to feed efforts to model environmentally-induced CMC strength degradation. However, experimental investigations of oxidant transport are complicated by the interplay between surface and internal oxidation processes. This presentation will describe recent efforts to study oxidation processes in heterogeneous, Si-based ceramics using carbide-based markers to track the ingress of trace oxidant concentrations, and then to apply this technique to develop materials offering improved performance. |