Hot corrosion behaviour of low Al NiCoCrAlY cladded coatings reinforced by nano-particles on a Ni-base super alloy

Three NiCoCrAlY coatings with Al content lower than 5 wt.% reinforced by different kinds of nano-particles with the same addition and one without nano-particles were prepared on a Ni-base super alloy using laser cladding technique. Hot corrosion of the NiCoCrAlY coatings in Na2SO4/K2SO4 (75:25, wt./wt.) mixture was performed at 1050 °C in static air. Results indicate that the hot corrosion resistance of the coatings with nano-particles is better than that of the one without nano-particles, among which the one with nano-CeO2 presented the best hot corrosion resistance. Effects of nano-particles on the hot corrosion behaviour were also discussed.

Research highlights
► Nano-particles can improve the hot corrosion resistance of NiCoCrAlY coatings
► Nano-CeO2 showed a good improvement on the hot corrosion resistance
► Microstructure refinement is a main factor in improving the hot corrosion resistance
► The active element effect of nano-CeO2 also play an important role