Anti-Corrosion Performance of the NiCrAlY Coatings Deposited by Two Different Spraying Technologies

In this study, nickel-base superalloy coatings are deposited on CrMoAl substrates by different spraying methods and the coatings are evaluated based on their microstructure, phase composition, surface and splat morphology, bond strength, and corrosion properties. In the experiments, NiCrAlY powders with a particle size range of 30-45 μm were sprayed by conventional air plasma and a new laser hybrid plasma spraying technique. The spraying parameters are presented along with test results, observations, and conclusions. The coatings produced by laser hybrid plasma spraying had an average porosity of 0.9%, a bonding strength of 117 MPa, and significantly better corrosion properties than the APS layers.