In situ observation of the deformation and fracture of an alumina-alumina ceramic-matrix composite at elevated temperature using x-ray computed tomography. Issue 7 (July 2021)

• Record Type: Journal Article
• Authors: Pirzada, Talha J.; Liu, Dong; Ell, Jon; Barnard, Harold; Šulák, Ivo; Galano, Marina; Marrow, Thomas J.; Ritchie, Robert O.
• Is Part Of: Journal of the European Ceramic Society. Volume 41:Issue 7(2021)
• Page Start: 4217
• Page End: 4230
• Publication Date: 2021-07
• Subjects: Ceramic-matrix composites -- Oxide-oxide composite -- X-ray computed micro-tomography -- Digital volume correlation -- In situ mechanical testing -- Failure mechanisms; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2021.01.030
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: The deformation and fracture of a 0/90° Nextel 720 mullite fibre / alumina matrix ceramic-matrix composite material has been observed by in situ synchrotron x-ray computed micro-tomography at ambient temperature and at 1100 °C. A three-point loading configuration was used and samples were loaded monotonically until final fracture. The flexural strength was found to be unaffected by temperature. 3D visualisation of the microstructure showed fracture occurred by propagation of internal cracks at stresses close to the flexural strength. Shear fractures propagated across fibre bundles that were oriented perpendicular to the flexural stress at both room temperature and 1100 °C. At the higher temperature, an additional failure mode of delamination was observed, that may arise from relaxation of thermal residual stresses and creep.