Impact damage resistance and tolerance of alumina-based oxide/oxide ceramic matrix composite upon one sided thermal shock and hold

In this study, ceramic matrix composite specimens constituting Nextel™720 fibers and alumina matrix were subjected to one-sided thermal shock and subsequent 30-min hold at temperatures of 1200℃, 1350℃ and 1500℃. The plates were then subjected to low velocity impact at 5 J impact energy, followed by edgewise compression with digital image correlation. No noticeable change in mass, roughness and specimen dimensions were observed after the thermal shock and hold event at any of the temperatures for any of the specimens. External and internal damage resulting from the impact event also showed no dependence on the thermal shock temperature. The percentage compressive strength retention after low velocity impact ranged from 61 % to 68 % for all cases considered, again with no trends observed based on shock temperature. However, the compressive modulus for the impacted panels that were exposed to high temperature were higher than the pristine (non-thermal shocked) impacted panels.