Corrosion and electrical properties of multi-layered coatings on stainless steel for PEMFC bipolar plate applications

In this study, various multi-layered coatings were deposited on the stainless steel substrates by the cathodic arc deposition technique to enhance the corrosion resistance and electrical conductivity of the specimens which may be used as the metallic bipolar plates of PEMFC. The results showed that all of the coated samples presented a better corrosion resistance than the bare stainless steel substrate. The TiN/CrN and CrN/Ti multi-layered coatings provided the best corrosion resistance of the coated stainless steels when they were subjected to polarization and immersion test in 10 vol.% H2SO4 solution. Additionally, CrN/Ti multi-layered coating exhibited better electrical conductivity as compared to TiN/CrN coating. Thus, the CrN/Ti multi-layered coating is considered to be the best candidate for PEMFC application in this study.