A Process to In-Situ Form Cooling Channels in SiC/SiC Composite Turbine Blades and Nozzles

Ceramic matrix composites (CMCs) such as SiC/SiC offer higher temperature capabilities than metals with cooling channels in turboshaft engines. Even higher operating temperatures are possible if cooling channels can be produced in SiC/SiC composites as well as silicon free environmental barrier coatings (EBC). The Phase I program demonstrated that cooling channels can be in-situ formed in the fabrication of SiC/SiC composites providing the ability to increase operating temperature which leads to improvements in horsepower-to-weight ratios of turboshaft engines. The Phase I program demonstrated a low cost process to produce SiC/SiC composites with properties at least equivalent to, or superior to any available SiC/SiC composite. It was demonstrated circular or oblong shape cooling channels in the 0.0016 to 0.060 inch diameter could be produced in-situ to the fabrication process that produces the SiC/SiC composite. This base processing will be utilized in Phase II to produce test panels for complete mechanical property, heat transfer coefficient and pressure drop characterizations. After validation of manufacturing methodology to meet performance goals for operation upto 3000°F, a component will be fabricated including a silica free environmental barrier coating (EBC) for rig testing at an engine manufacturer.