LAUSR

In order to improve the corrosion resistance of zirconium alloy in high temperature and high pressure water environment, Cr/TiAlN coating and Cr/TiAlSiN coating were prepared on the surface of Zr-4 alloy by multi-arc ion plating (MAIP). The corrosion resistance of the two coatings in the autoclave was compared by various analytical methods:The film-based bonding force of the coating was detected by an automatic scratch test; the microstructure of the coating was observed by scanning electron microscope (SEM); the porosity and the quantity of large particles on the surface were analyzed by Image J software; the phase of the coating was analyzed by x-ray diffractometer (XRD); the type and content of the coating were detected by energy dispersive spectrometer (EDS). The experiment result shows that the surface of the two coatings is relatively flat, and the surface of the Cr/TiAlSiN coating is finer than that of the Cr/TiAlN coating, and the number of large particles is small and the density is high. The critical loads that the Cr/TiAlN coating and the Cr/TiAlSiN coating can withstand are 34 N and 29 N respectively. Under the experimental conditions, part of the Cr/TiAlN coating peeled off and localized corrosion occurred; A large amount of ZrO2 was detected on the surface of the sample, the coating was destroyed and the protective effect was lost. While, the Cr/TiAlSiN coating is almost intact, it effectively preventing the substrate from being corroded. In conclusion: the coating quality of multi-arc ion plating Cr/TiAlSiN coating is better than that of Cr/TiAlN coating, and the corrosion resistance is better. It can protect the zirconium alloy matrix effectively. However, the residual stress is generated due to the presence of Si in the Cr/TiAlSiN coating, which resulting in a low film-based bonding force.