Hot Corrosion Resistance of Ni Coated Y₂O₃ Powders Dispersion Strengthened Nickel-Based Superalloy

In order to improve hot corrosion resistance of Hastelloy X alloy, the Ni coated Y2O3 powders were prepared by electroless nickel plating method, and then taking them as dispersion phase and Hastelloy X particles as substrate to prepare a dispersion strengthened nickel-based superalloy. A salt solution, including 75wt% Na2SO4 and 25wt% NaCl, were coated on the alloy and following hot corrosion test at 850 ℃. The hot corrosion resistance of the alloy, substrate alloy and ordinary Y2O3 strengthened alloy were compared. The result show that nickel plating could make Y2O3 particles uniform dispersion in the substrate, dispersed Y2O3 particles acted as heterogeneous nucleation sites for Cr2O3, boosting the formation of a protective Cr2O3 oxide scale. At the same time, Ni coated Y2O3 particles could promote the adhesive force of oxide scale, impede the spallation of oxide scale, and enhanced hot corrosion resistance of substrate alloy.