Synergy Effects of Ceramic Matrix Composites Under Engine Environments

Synergy effects of simulating engine operational environments were appraised in two different gas-turbine grade SiC/SiC ceramic matrix composites (CMCs). The engine environments employed in the work included foreign object damage (FOD), erosion, CMAS (calcium magnesium aluminosilicate), and elevated-temperature exposure. The effects of eight different environments were assessed individually as well as synergistically (in combination) through damage morphologies and strength assessments. Despite significant complexity attributed to environmental and materials variables involved, the results showed that FOD was the most degrading element of all not only individually but also synergistically. The strength degradation of the two SiC/SiC CMCs subject to FOD and FOD-and-CMAS amounted to 30–50% when compared to as-received, pristine strengths.