PITTING RESISTANCE OF TIN DEPOSITED ON INCONEL-600 BY PLASMA-ASSISTED CHEMICAL-VAPOR-DEPOSITION

Abstract

TiN films were deposited on Inconel 600 by PACVD using the gaseous mixture of TiCl4, N-2, H-2, and Ar in order to increase the pitting resistance of Inconel 600. The pitting resistance was examined using a potentiodynamic polarization technique with a chloride solution. The effect of chloride concentration in the electrolyte on the pitting potential was also investigated. Inconel 600 coated with TiN film shows a superior pitting resistance to that without TiN film in condition that the thickness of the film is greater than a certain critical value. As the deposition temperature as well as the RF power increases, the residual Cl concentration in the film decreases, resulting in the improvement of the pitting resistance. However, the TiN films deposited at too high RF powers, even though the Cl concentration in TIN film is very small, show inferior pitting resistance, which is due to the formation of the network type microvoids structure.