Post-processing methods and points for attention of abradable sealing coatings

       For an abradable coating, it is a composite formed from a metal or heat-resistant alloy cladding a core material. Since the core material is soft, light, brittle, and easy to scrape non-metallic particles, such as graphite, diatomite, bentonite, hexagonal boron nitride, ZrO2, etc., the pressure and heat generated by grinding will change the properties of the coating , therefore, the grinding method is not used for the processing of the abradable coating, but the turning method is recommended. When turning, it is necessary to strictly control the processing parameters, which is as important as controlling the spraying parameters.



When turning abradable coatings, generally smaller feeds, slower rotations and slower passes are used. For example, for Metco 310NS aluminum-clad graphite abradable coating sprayed with Metco 6P flame spray gun, it is recommended to use sharp tungsten carbide turning tools for dry turning, the line speed of the lathe is controlled at 2m/s, and the amount of passes is controlled at 0.06mm/ r, the feed amount is controlled at 0.25mm/time. When turning, ensure that no particles are scraped out of the coating, and the turned surface must be thoroughly cleaned before use.