Mechanical and microstructural characteristics of detonation gun sprayed NiCrAlY + 0.4 wt% CeO2 coatings on superalloys

The microstructure and mechanical properties of detonation gun sprayed NiCrAlY + CeO2 alloy coatings deposited on superalloys were investigated. The morphologies of the coatings were characterized by using the techniques such as optical microscopy, X-ray diffraction and field emission scanning electron microscopy/energy-dispersive analysis. The coating depicts the formation of dendritic structure and the microstructural refinement in the coating was due to ceria. Average porosity on three substrates was less than 0.58% and surface roughness of the coatings was in the range of 6.17–6.94 μm. Average bond strength and microhardness of the coatings were found to be 58 MPa and 697–920 HV, respectively.