AN EROSION RESISTANT BLADE COATING FOR THE T64 ENGINE COMPRESSOR

1Titanium compressor blades suffer unacceptable erosion damage to solid impact. Polymeric protective coatings are ineffective in solid particle environments and are unable to withstand the high temperature environment of the T64 engine compressor. The broad damage area of compressor blades makes metallic protective coatings, such as have been developed for helicopter blades, unacceptable from a weight penalty. Conventional ceramic coatings have demonstrated excellent erosion resistance, but have been erratic in performance, difficult to apply to complex surfaces, and have poor adherence properties. A sol-gel derived ceramic coating offers tailorable porosity characteristics which should optimize erosion and toughness properties. The sol-gel process lends itself to applications to complex surfaces. A novel reactive primer will covalently bond the ceramic coating to the titanium substrate. Sol-gel processing studies will address tailorability of the alumina-silicate composition and microstructure. Pull-off tests will assess coating adherence achieved by the reactive primer. DNA's dust erosion facility will be used to determine solid impact erosion resistance as a function of ceramic coating characteristics. Fatigue life and repair tests will be conducted to assess the application limits of this coating. TPL will be assisted by the Center for Micro-Engineered Ceramics in coating development and PDA Engineering in erosion testing. Combined, the program team has complete capabilities to achieve an engineering solution.