Abstract: In order to improve corrosion resistance and electrical conductivity of titanium-based bipolar plate, the surface of TA2 pure titanium was treated by double glow ion carburizing, and vanadium was doped in the carburizing process to reduce the carburizing temperature. The structure, chemical composition and phase composition of the modified layer were characterized by scanning electron microscopy, energy dispersive analysis and X-ray diffraction. The interface contact resistance and corrosion resistance of the modified layer were measured. The results show that under the optimized preparation process parameters, dense TiC modified layer and vanadium-doped carburizing modified layer are formed on the surface of TA2. When the compaction force is 140 N/cm², the interface contact resistivities of the vanadium-doped carburizing modified layer prepared at 730 ℃, TiC modified layer prepared at 850 ℃ and TA2 matrix are 1.17, 3.66 and 14.71 mΩ/cm². The self corrosion current densities of the vanadium-doped carburizing modified layer prepared at 730 ℃ and TiC modified layer prepared at 850 ℃ under the simulated bipolar plate working environment are 5.238 and 7.563 μA/cm², respectively, which are 1 order of magnitude lower than that of TA2 substrate. Doping vanadium in the process of ion carburizing can effectively reduce the process temperature of carburizing and improve the conductivity and corrosion resistance of TA2 matrix.

Key words: TA2 titanium bipolar plate, vanadium doping, TiC modified layer, corrosion resistance, electrical conductivity