Synthesis and characterization of Ni–Al–Y2O3 composite coatings with different Y2O3 particle content

In this work, Ni–Al–Y2O3 composite coatings with different contents of Y2O3 nanoparticles were prepared from a conventional Watt bath containing different Y2O3 particle loadings (1 g/L, 2 g/L, 5 g/L, 10 g/L). The influences of Y2O3 particle loadings in the bath on the composition, texture, grain size, microstrain, residual stress and hardness of the composite coatings were investigated. The anti-corrosion of the composite coating in NaCl and NaOH solutions were also evaluated in detail. The results showed that the Y2O3 particle content in the composite coatings increased with increasing the particle loadings. The (2 0 0) preferred orientation of the composite coating evolved to (1 1 1) preferred orientation with increasing Y2O3 particle loadings. The composite coating deposited at 5 g/L showed the smaller grain size, lower tensile residual stress and the maximum hardness value. Corrosion experiment showed that the composite coating deposited at 5 g/L exhibited the best corrosion resistance both in NaCl and NaOH solutions.