Brush Seal Shaft Wear Resistant Coatings

In a previous SBIR program, Technetics developed a ceramic fiber brush seal. The new brush seal material now requires a shaft coating. The coating is needed to protect the shaft against wear, which could cause major engine damage. Current coatings are not capable of withstanding the abrasiveness of the ceramic fiber. This proposed effort is to identify a coating and coating application method that will complement the newly developed ceramic brush brush seal, as well as existing metallic brush seals. It is the intent of the proposed work to evaluate existing coatings, or minor variations therof, to fill the requirements of a low wear, high temperature brush seal shaft coating. This coating will be used in conjunction with the ceramic brush seal to produce a high temperature, high speed, low wear, high sealing, efficiency, secondary flow seal. A number of screening tests are proposed for the candidate coatings. The tests include thermal shock, abrasive wear, sliding wear at representative temperatures/speeds and sliding friction tests. These tests will determine a candidate coating's ability to be applied to the ceramic brush seal system and achieve the stated objectives. Test rigs utilized throughout the proposed work exist at Technetics or are slight modifications thereof.