Reactive Sputtered Ytterbium Silicate Environmental Barrier Coatings for Protection of Mo-Si-Based Alloys

The implementation of a structural material into the hot section turbine engine requires protection against oxidation and water vapour. Since Mo-Si-based alloys do not provide this on their own over long period exposure time, necessity for protective coatings becomes inevitable. Rare earth silicates, especially Yb-silicates, are known great potential to protect silica vapour recession also behaviour due low reactivity. Reactive pulsed DC co-sputtering was investigated used produce two-layered coating Yb2Si2O7 Yb2SiO5. layers were implemented four-layered environmental barrier system combined with bond coat consisting graded Mo-Si interlayer thin Si top layer intended form slow-growing silica. EBCs tested up 100 h at 1200 °C 800 isothermally in air three different show promise protection. pesting phenomenon completely suppressed.