Nitride based Nanocomposite Bond Coat for SiCf-SiC composites(16-RD-862)

ABSTRACT: This Phase I SBIR program seeks to develop a new EBC system with high temperature bond coat increasing engine operation temperature as well as alleviating surface recession of SiCf-SiC ceramic matrix composites (CMC). Oxidation and water resistance of the new bond coat alloy, along with a thermal shock resistance, will be explored. EBCs have been applied to the SiCf-SiC CMCs hot sections of aircraft turbine engines to mitigate an active oxidation, and increase fuel efficiency and to extend the life of CMC components; however, there remain the issues related to upper temperature limit and the material recession in the presence of high temperature water vapor. These issues are closely linked to low thermal stability of the bond coat in SOA EBC systems and the active oxidation.Due to this fact, current efforts are focused on developing new bond coat alloys with use temperature up to 2700oF or higher. We propose the development of new, high temperature (>2700oF) bond coat compatible with SOA EBC systems to achieve a high fuel efficiency and a longer lifetime.; BENEFIT: EBCs are used for the SiCf-SiC CMCs hot sections of the aircraft engines but limited by unpredictable lifetimes and poor reliability. A new bond coat compatible with SOA EBC systems could significantly increase use temperatures and fuel efficiency, and reduce surface recession. Full incorporation of advanced EBC with a new bond coat alloy into the military aircraft and commercial turbine engines will be expected.