ELECTROCHEMICAL AND SIMS STUDIES OF CATHODICALLY FORMED HYDRIDE LAYERS ON TITANIUM

The aims of the present work are to study the influence of the hydride layer (the formation of which during cathodic polarization has been known for quite a long time) on the rate of HER, to explore the applicability of SIMS to detect the presence of hydride and to determine the thickness of such layers. The present measurements show that the formation of hydride suppresses the HER, and that the suppression becomes constant as the hydride layer forms a continuous layer. This is not compatible with the previous literature where the formation of hydride has been reported to stimulate the HER. The present measurements show that the SIMS technique is well suited to detection of absorbed hydrogen in titanium. However, the present effort to use SIMS depth profile measurements to determine the thickness of the hydride layer was unsuccessful. The H- signal shows a smooth decrease from which it is impossible to determine the film thickness. Possible causes for this smooth decrease have been discussed. © 1990.