Microstructure and friction-wear performances of laser-cladded nano-CeO2–reinforced NiCoCrAlY coatings at high temperature

Abstract

Nano-CeO2–reinforced NiCoCrAlY coatings were fabricated on Ti6Al4V alloy using laser cladding. The morphologies, chemical compositions, and phases of obtained coatings were analyzed using a scanning electron microscope, energy-dispersive spectrometer, and X-ray diffraction, respectively, and the effects of nano-CeO2 mass fraction on the coefficient of friction and the wear rate of NiCoCrAlY coating at 600 °C were investigated using a ball-on-disk wear test. The results show that the nano-CeO2–reinforced NiCoCrAlY coating is mainly composed of NiTi2, Ti3O, CoO, and β-Ti phases, while the new phases of AlTi3 and (Ni, Co)2Ti4O are formed after the wear test. The average coefficients of friction of NiCoCrAlY coatings with the nano-CeO2 mass fractions of 0%, 2%, 4%, and 6% are 0.699, 0.655, 0.636, and 0.615, respectively, and the corresponding wear rates are 4.04 × 10−7, 3.95 × 10−7, 3.13 × 10−7, and 2.35 × 10−7 mm3 N−1 m−1, respectively, which decrease with the increase of nano-CeO2 mass fraction. The wear mechanism is primary adhesive wear and oxidation wear, accompanied by slight abrasive wear, and the addition of nano-CeO2 is the main factor that is enhancing wear resistance.