Hydrogen absorption monitoring of sputter-deposited Ti film in seawater

Hydrogen absorption in Ti film sputter-deposited on glass plate immersed in sodium chloride solution of seawater concentration was monitored using resistometry. Increase in electric resistance due to increase in hydrogen content or growth of hydride in Ti during cathodic polarization was evaluated. A monitoring system was developed in which a couple of Ti films were used to reduce influence of temperature-fluctuation on resistance; one was used as a working electrode exposed to electrolyte solution and another was used as a reference resistance with silicon sealant coating. Two films were connected electrically in series, and applied by constant AC to measure resistance of the working electrode as relative value against the reference resistance. Increase in resistance during cathodic polarization at −0.8 VRHE was observed after some induction period. Scratching test during cathodic polarization did not provide major effect on hydrogen absorption.