TiN films for metallic bipolar plates were synthesized by closed-field unbalanced magnetron sputtering (CFUBM) and the properties were controlled by adjusting the N-2 partial pressure. The corrosion behaviors of TiN films were investigated by potentiodynamic tests and electrochemical impedance spectroscopy (EIS) measurements under the condition of an aerated 1 M H2SO4 + 2 ppm HF solution at 70 degrees C with a constant potential of 600 mV(SCE). The results revealed that the variation of N-2 pressure had an influence on the corrosion resistance of TiN coating. N-2 partial pressure of 0.4 mTorr showed good corrosion resistance with the lowest corrosion current density and the highest charge transfer resistance due to the low porosity. (c) 2007 Elsevier B.V. All rights reserved.