| About this Abstract |
| Meeting |
Materials Science & Technology 2020
|
| Symposium
|
Advanced Characterization of Materials for Nuclear, Radiation, and Extreme Environments
|
| Presentation Title |
Characterization of Stress and Environment Dependent Fracture Mechanisms of SiC/SiC CMCs |
| Author(s) |
Morgan Claire Price, Clifton Bumgardner, Frederick Heim, David Roache, Xiaodong Li |
| On-Site Speaker (Planned) |
Morgan Claire Price |
| Abstract Scope |
Silicon carbide fiber reinforced silicon carbide matrix (SiC/SiC CMCs) composites, which are used in nuclear reactor applications for superior high temperature and corrosion resistant properties, exhibit degraded mechanical strength and embrittlement under sustained or slowly ramping stress levels. The morphology and distribution of microcracks was evaluated during tension and expanding plug tests with variable strain rates and levels of environmental exposure (up to 1200 °C in inert and oxidizing environments). All tests were conducted with in-situ monitoring of local deformation using stereoscopic digital image correlation and acoustic emissions to characterize microcrack growth. Experimental crack growth mechanisms, including crack opening displacement with stress level, were used to validate a finite element model to predict the fracture energy release. Thus, this study aims to elucidate the coupled stress-based and environmental-based mechanisms driving crack initiation and propagation within SiC/SiC composites. |