ABSTRACT
Objective To investigate the effects of titanium nitride(TiN) coating on corrosion resistance of dental Co-Cr alloy in the simulated oral environment. Methods The Co-Cr alloy commonly used was casted with specimen sized of 10 mm× 10 mm×3 mm. Then the specimen was coated with a thickness of 2.5 μm TiN coating on the surface by multi-arc physical vapor deposition. The Tafel polarization curves of the specimen before and after coating titanium nitride in artificial saliva were measured by electrochemical station. Results From the Tafel polarization curves, the specimen after coating TiN showed that both anodic polarization curve and cathodal polarization curve were fiat, natural corrosion potential moved to the positive way, and passivation interval got longer. From the annular anodic polarization curves, the specimen after coating TiN had almost no "delay area". Conclusion TiN coating can improve corrosion resistance of Co-Cr alloy.
ABSTRACT
Objective: To study the corrosion resistance of orthodontic magnet with titanium nitride coating in artificial saliva. Methods: 6 samples of magnet in the size 3 mm?5 mm?7 mm were prepared.3 of them were coated with titanium nitride by plasma enhanced chemical vapor deposition,another 3 without coating were used as controls.The samples were immersed into artificial saliva at 37 ℃ for one month. Then the surface characters of two kinds of magnets were observed with the naked eye and by electron-probe microanalysis (EPMA). Results: The surface of the magnets with titanium nitride coating was fine and close in texture and there were no cleft and disintegrated area. However, that of the magnets without titanium nitride coating was uneven and coarse in texture,and there were evident clefts and disintegrated areas. Conclusion: The corrosion resistance of orthodontic magnets with titanium nitride coating is stronger than that without coating.