Effect of TiN coating on corrosion resistance of dental NiCr alloy
Hu, B.; Chen, J.
Shanghai Kou Qiang Yi Xue 18(1): 73-76
2009
ISSN/ISBN: 1006-7248 PMID: 19290433 Document Number: 637813
To investigate the effect of titanium nitride coating on corrosion resistance of NiCr alloy in the simulate oral environment. The NiCr alloy commonly used for porcelain crown was cast with specimen size of 10mm x 10mm x 3mm. Then the specimen was coated with a thickness of 2.5 microm titanium nitride 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. From the Tafel polarization curves, the specimen after coating titanium nitride showed that both anodic polarization curve and cathodal polarization curve were flat, and gained the higher natural corrosion potential, lower passivation maintaining current, longer passivation interval. The natural corrosion potential increased from -0.2487 V to -0.0685 V. The natural corrosion current density decreased from 0.2628 microA.cm(-2) to 0.1895 microA.cm(-2). The rupture potential increased from 0.8505 V to 1.2566 V. Titanium nitride coating can improve corrosion resistance of NiCr alloy.