About this Abstract |
| Meeting |
Materials Science & Technology 2020
|
| Symposium
|
Ceramic Matrix Composites
|
| Presentation Title |
In Situ Observation of Crack Formation in CMCs Using X-ray Computed Tomography up to 1200°C |
| Author(s) |
Dong (Lilly) Liu, Jon Ell, Harold Barnard, Stefan Reh, Robert Ritchie |
| On-Site Speaker (Planned) |
Dong (Lilly) Liu |
| Abstract Scope |
A unique device permits in situ loading with real time X-ray computed tomography (XCT) imaging was used to study the deformation and fracture of a DLR WHIPOX CMC over a range of temperatures (RT, 900°C, 1050°C&1200°C). XCT scans were taken at multiple loading steps to capture the crack formation and propagation. The measured flexural strength was consistent with ex situ uniaxial tension and bending tests indicating the size of the samples used was adequate. The RT failure comprised of diffused fibre breakage accompanied by fibre/matrix delamination linking up existing pores. At 1050&1200°C, fibre/matrix delamination became the primary failure mechanism. Digital volume correlation (both local and global approaches) was used to derive the 3D displacement field and stress-strain behavior were extracted. Finally, residual stresses mapping in the fibre and matrix were conducted and the relaxation of these stresses was considered to have contributed to the high temperature delamination. |