Cyclic oxidation behavior of electron beam physical vapor deposition NiAlHf and NiAlHfCrSi coatings at 1150 °C

NiAlHf and NiAlHfCrSi coatings were deposited by electron beam physical vapor deposition (EB‐PVD). The grain size and orientation of NiAlHf and NiAlHfCrSi coatings were determined by electron backscatter diffraction (EBSD). The NiAlHf coating reveals a more uniform grain size compared to NiAlHfCrSi coating, while the NiAlHfCrSi coating shows a <111> preferential orientation which is parallel to the normal direction of the surface of the coating. The cyclic oxidation behavior of NiAlHf and NiAlHfCrSi coatings at 1150 °C was investigated. Compared to NiAlHf coating, the NiAlHfCrSi coating shows improved resistance to cyclic oxidation and scale spallation. The effect of grain size and orientation on the cyclic oxidation behavior of NiAlHf and NiAlHfCrSi coatings were investigated at 1150 °C.