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 nitriding. Hydrogen concentration in the titanium nitride films was directly measured by elastic recoil detection (ERD) analysis, it was confirmed that the titanium nitride film worked as a hydrogen permeation barrier at high temperatures. When titanium coexisted with titanium nitrides, the hydrogen impermeability decreased with the increase of the volume concentration of titanium, which worked as the hydrogen-diffusing medium. (C) 2000 The Electrochemical Society. S0013-3651(00)07-04 1-5. All rights reserved.