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Creep/rupture behavior of melt-infiltrated sic/sic composites being investigated
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Hurst, Janet B. |
| Copyright Year | 2001 |
| Description | The failure behavior of melt-infiltrated SiC/SiC ceramic matrix composites is under investigation at the NASA Glenn Research Center as part of NASA's Ultra-Efficient Engine Technology Program. This material was originally developed under the High Speed Research Office's Enabling Propulsion Materials Program. Creep and rupture data provide accelerated testing information to predict material behavior under engine use situations (1500 to 2400 F). This information gives insights into various material development paths to improve composites as well as improve understanding of failure mechanisms. The left figure shows the fracture surface of a CMC material following over 200 hr of testing at 2400 F. This surface demonstrates the kind of fibrous pullout desirable for maximum crack deflection, hence non-brittle failure. Microscopy suggests that creep and rupture of these materials can best be considered as a probabilistic property, rather than a material property. Fiber failure occurs first in isolated regions, while stronger adjacent fibers remain intact. The right figure shows a region where oxide deposits blur and round the fiber images. Because the oxidation kinetics of SiC are well understood, this oxide scale can be used as a measure of the length of time various regions of the composites have been exposed to the environment, hence providing vital information regarding the sequence of failure. The oxide scale in the right figure indicates an early failure of this tow of fibers, whereas adjacent tows remain oxide free, suggesting failure much later in time. The path of various cracks can be followed throughout the composite in this manner, suggesting failure mechanisms. |
| File Size | 92551 |
| Page Count | 2 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20050196561 |
| Archival Resource Key | ark:/13960/t74v1js2v |
| Language | English |
| Publisher Date | 2001-03-01 |
| Access Restriction | Open |
| Subject Keyword | Composite Materials Cracks Ceramic Matrix Composites Creep Properties Accelerated Life Tests Deposits Reaction Kinetics High Speed Oxidation Fracturing Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
