Influence of Heat Treatment on Corrosion-Wear Behavior of Ni-Based Coating in Artificial Seawater

摘要

NiCrAlY coatings were fabricated by atmospheric plasma spraying. The influence of the heat treatment on the corrosion-wear behavior of the coatings in artificial seawater was investigated. The microstructure of the coatings became denser and more homogeneous after the heat treatment. After heat treatment at 1100 degrees C, the coating had the fewest pores and cracks and the oxide dispersive strengthening phase of Y2O3 was clearly increased to form a layer approximately 10 nm thick and uniformly distributed in the matrix. The heat treatment effectively improved the microhardness and corrosion-wear properties of the coatings. This coating had the highest microhardness of 371.1 HV, the lowest friction coefficient, and a wear rate of 0.24 and 1.01 x 10(-6) mm(3)/Nm and the lowest corrosion rate after heat treatment at 1100 degrees C, giving it excellent corrosion-wear properties.