Abstract: In order to investigate the effect of the transition layer on the surface properties of Cr_0.23C_0.77 amorphous modified films applied on the stainless steel bipolar stack of fuel cells, a pitting-resistant titanium alloy transition layer was prepared between the Cr_0.23C_0.77 film and the 316L stainless steel substrate by using the pulsed bias arc ion plating technique. Firstly, four industrial titanium alloys, TA1, TA9, TA10 and Ti35, were selected on the 316L stainless steel substrate for the deposition of the pre-selected transition layer materials, and the resulting samples were tested for corrosion resistance. The results showed that the contact resistance of the bipolar plate with Ti35 transition layer was 3. 0 mΩ·cm² (at 0.6 MPa) and the water contact angle was 0. 0 mΩ·cm² (at 0.6 MPa). The corrosion resistance was significantly improved on the basis of the hydrophobic performance with a water contact angle of more than 100°. Under the dynamic potential corrosion measurement conditions of the simulated cathodic environment, an obvious plateau passivation zone appeared in the corrosion curve, and the corrosion current was kept below 10-6A-cm-2 level in a wide potential range from -0. 3 to 0. 9 V, and the passivation breaking potential was as high as 1. 0 V or more. This will help to improve the surface protection performance and service life of the bipolar plate.

http://dx.doi.org/10.13922/j.cnki.cjovst.2018.11.10