The aim of this research is the evaluation of the influence of TiN, CrN and TiN/CrN nanostructured coatings on corrosion resistance of nickel-chromium dental alloy in artificial saliva environment with two pH levels (3.0 and 6.5). Nickel-chromium alloy tested in this study were more resistant to corrosion in artificial saliva conditioning media when coated with different types of coating materials, as compared to uncoated alloy. The electrochemical measurements propose that the alloy with CrN coating has shown a high corrosion resistance in different pH levels. The superior passivation of CrN monolayer coating in modified Fusayama artificial saliva solution may be concluded from two essential factors, passive range, and corrosion current density. The passive range is well-developed, while the corrosion current density is much lower if compared to the other groups. Also, the Nyquist and polarization plots reveal that TiN, CrN and TiN/CrN nanostructured coatings have an excellent corrosion resistance which is considered much higher if compared to the substrate. The values of corrosion current density for CrN nanostructured coating in artificial saliva environment with two pH levels of 3.0 and 6.5 were 1.373 × 10−8 and 5.416 × 10−8 A.cm−2, respectively that were the lowest corrosion current density values among the other samples.
