Micromechanical properties of vapour-exposed SiCf/BN/SiC ceramic-matrix composites. Issue 7 (July 2022)

• Record Type: Journal Article
• Authors: De Meyere, Robin M.G.; Gale, Louise; Harris, Stephen; Edmonds, Ian; Chamberlain, Adam L.; Marrow, Thomas J.; Armstrong, David E.J.
• Is Part Of: Journal of the European Ceramic Society. Volume 42:Issue 7(2022)
• Page Start: 3148
• Page End: 3155
• Publication Date: 2022-07
• Subjects: Micromechanical testing -- Oxidation -- SiCf/SiC -- Interfacial shear strength -- Fibre push-out; 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.2022.02.022
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: SiCf /BN/SiC Ceramic-Matrix Composites are candidate materials for aero-engines, but their interphase stability after potential low-temperature water-vapour exposures during flight cycles is not well known. The examination of these composites exposed for 50, 250 and 500 h at low temperature (65 °C) and 95% relative humidity was therefore performed, in order to understand if resulting oxidation products affected the mechanical properties at the micro-scale. The composites were subject to fibre push-out tests to compare pristine from degraded composites. It was found that whilst the sample exposed for 50 h had no significant change from pristine, the samples exposed for 250 and 500 h had a clear decrease in interfacial shear strengths measured. Parallel studies also revealed that whilst damage was strongly localised, the diffusion of water within the composite was not fully complete at exposure times between 50 and 250 h. The permeability of the CMC was shown to be affected at longer exposure times where differences in mechanical performances even between tows and within tows were noted.