Improved oxidation and hot corrosion resistance of Ta-doped NiAlY alloy at 750 degrees C

The oxidation and hot corrosion behaviors of the NiCrAlY, NiAlY, and Ni-xTa-Al-Y alloys (x = 1, 3, 5, and 10 wt%) were investigated at 750 degrees C. The doped Ta promoted the formation of the protective alpha-Al2O3 scales. The NiTaAlY alloys exhibited an improved oxidation resistance compared with the NiAlY alloy. Under the NaCl-induced hot corrosion test, the addition of Ta reduced the consumption of Al and inhibited the internal corrosion of the alloys. The Ni-xTa-Al-Y alloys (x = 1, 3, 5, and 10 wt%) showed better resistance to the NaCl-induced hot corrosion. Moreover, the hot corrosion mechanism of the tested alloys was also discussed.