Interlaminar Tensile Strength Testing of CMCs at High Temperatures Enabled by Oxidation Resistant Ceramic Cement Derived from ZrB2-SiC Precursor

This Phase II effort will demonstrate a standard method of measuring the high-temperature, inter-laminar tensile (HT-ILT) strength of ceramic-matrix composites (CMCs). Jet engines with higher turbine gas temperatures for higher specific thrust and efficiencies require the use of SiC/SiC CMCs with known mechanical properties at high temperature (2300 degrees F). The typically poor ILT strength of CMCs containing 2-D woven fibers imposes artificial limits on the design of hot section components. The method is needed by engine developers to avoid the expense of over-built airfoil components, particularly rotating components. It would not only help determine the design limits of CMC materials, but also aid the discovery of ways to improve ILT strength. Furthermore, HT-ILT testing could be used to screen materials for processing defects and qualify them for service (i.e., quality assurance testing as well as studies of material fatigue). The program will extend the room-temperature method, ASTM C1468 for ILT testing of CMCs, to testing at =2400 degrees F, by demonstration and validation of a new ceramic-based adhesive capable of 6 ksi strength at high temperatures.