Oxidation Behavior of NiCr/YSZ Thermal Barrier Coatings (TBCs)

Nichrome (NiCr) coatings are widely used to provide resistance against oxidation and corrosion in many machine components. TBCs must include bond coatings that are resistant to oxidation resulting from high-temperature operating conditions. In the present study, NiCr powders were sprayed on nickel-based superalloy Inconel 718 substrates using atmospheric plasma spray (APS) technique. Bond-coated substrates were coated with yittria stabilized zirconia (YSZ). As such, the TBC samples were kept at 1000 degrees C for 8 h, 24 h and 50 h in high temperature furnace and their isothermal oxidation behavior was investigated. Microstructure and phase change properties of TBCs before and after isothermal oxidation were then studied and analyzed