Hydrogen impermeability of TiN films and its dependence on nitrogen concentration at high temperatures

The hydrogen impermeability of titanium nitride films and its dependence on nitrogen concentration have been estimated by molten salt electrochemical techniques at 723 K. Surface nitriding of titanium substrates was conducted by two methods, i.e., gas nitriding and molten salt electrochemical nitrid ing. Hydrogen concentration in the titanium nitride films was directly meas ured by elastic recoil detection (ERD) analysis, it was confirmed that the titanium nitride film worked as a hydrogen permeation barrier at high tempe ratures. When titanium coexisted with titanium nitrides, the hydrogen imper meability decreased with the increase of the volume concentration of titani um, which worked as the hydrogen-diffusing medium. (C) 2000 The Electrochem ical Society. S0013-3651(00)07-04 1-5. All rights reserved.