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

Continuous fiber reinforced ceramic matrix composites (CMCs) are desired for aerospace applications due to the strength and toughness imparted by incorporation of embedded long fibers of carbon or silicon carbide into a ceramic matrix. Oxidative degradation at high temperature is the predominant factor limiting the use of CMCs in jet engine applications. The components can swell when heated in air, which suggests poor interlaminar tensile (ILT) strength. A method for measurement of ILT strength of CMCs at the high temperatures to which they are exposed (2300 °F) is highly desired by engine developers and the composites R&D community, but extension of the testing standard is not possible without development of an ultrahigh temperature adhesive. This program will utilize a new high-yield ZrB2 ceramic derived from polymer precursor to demonstrate the feasibility of using a ceramic cement to enable ILT strength testing at high temperature in air. Thor Technologies has teamed with the Materials Engineering Group of Southern Research Institute and a provider of SiC test fixtures to plan and execute the following proposed effort, which will combine the new precursor with appropriate additives for surface fluxing, to achieve reactive bonding of the cement to the CMC surface.