Cyclic oxidation of Y2O3-modified ultrafine-grained Ni3Al alloy coating at 900 °C

Ni3Al coatings with and without Y2O3 particles were developed by annealing the electrodeposited Ni-Al composite coatings with and without Y2O3 particles at 800 °C for 3 h. The microstructures and cyclic oxidation performances of the produced Ni3Al coatings were comparatively investigated, with the emphasis on the effect of Y2O3. SEM/EDAX and TEM characterizations showed that the dispersion of Y2O3 refines the grains. Oxidation at 900 °C for 100 h showed that the addition of Y2O3 significantly improved the cyclic oxidation resistance of Ni3Al coating. The effect of Y2O3 on the microstructure and the oxidation of the Ni3Al coating were discussed in detail.