1050 °C isothermal oxidation behavior of detonation gun sprayed NiCrAlY coating

NiCrAlY coating was deposited on a single crystal Ni-base superalloy by detonation gun spraying. By means of XRD, SEM and EDS, isothermal oxidation behavior of the coatings at 1050 °C were studied. The results showed that detonation gun sprayed NiCrAlY coatings held a favorable oxidation resistance. Their oxidation kinetics at 1050 °C obeyed the parabolic law. α-Al2O3 scale was formed on the coating surface and kept almost intact after oxidation for 300 h. Internal oxidation led to the formation of Al2O3 at the coating/substrate interface, and needlelike (Al, N) compounds appeared in the undersurface area of the substrate. [Copyright &y& Elsevier]