Chemically Modified SiC/SiC for In Situ Growth of Nonvolatile, Environmental Barrier Scale Navy SBIR FY2009.1 Sol No.: Navy SBIR FY2009.1 Topic No.: N091-011 Topic Title: Chemically Modified SiC/SiC for In Situ Growth of Nonvolatile, Environmental Barrier Scale Proposal No.: N091-011-1567 Firm: Thor Technologies, Inc. 3013 Aztec Road NE Albuquerque, New Mexico 87107 Contact: Larry Kepley Phone: (505) 830-6986 Web Site: thortech.biz Abstract: For significant advancements to occur in the implementation of ceramic matrix composites (CMCs) in aeroengine airfoil applications, silicon carbide (SiC) ceramic matrix that forms corrosion resistant scale is needed for the combustion environment. Particularly troublesome is the accelerated surface oxidation and recession that proceeds due to reaction of the native silica scale with steam in the high-temperature turbine environment. As opposed to the more convention application of environmental barrier coatings (EBC) by plasma spray to meet this challenge, the proposed effort will develop an steam-resistant matrix material for use in SiC/SiC CMCs. More specifically, chemically modified SiC-matrix CMC panels will be fabricated by PIP processing using rare earth-doped polymer precursors. Evaluation of the resulting CMCs will proceed by measuring their oxidation resistance under aggressive, accelerated aging conditions (steam + O2 at high temperatures) that simulate harsh aeroturbine environment. A wide variety of materials property testing will be performed to measure the mechanical effects on the effect of doping the matrix both before and after aging of specimens. Benefits: The proposed CMC materials and fabrication processes could be of benefit to several military aeroengine and stationary gas turbine applications design efforts. These lightweight materials could offer excellent thermochemical stability in combination with high tensile strength, high stiffness, low thermal expansion, low density, and long durability. Gains in thrust-to-weight ratios and cost benefits from the use of CMCs in the Joint Strike Fighter and commercial aircraft engines could be realized. Return