Corrosion resistance and conductivity of NbN-coated 316L stainless steel bipolar plates for proton exchange membrane fuel cells. (March 2022) - Chen, Mohan
Abstract: NbN coatings were deposited by multi-arc ion plating at different nitrogen partial pressure (PN ) to improve the corrosion resistance and conductivity of metallic bipolar plates. With increasing PN, the phase composition of the coating transformed from a mixture of β-Nb2 N and δ'-NbN to δ-NbN, which was accompanied by grain refinement. The coating deposited at a relatively high PN (3.5 Pa) exhibited the lowest ICR and corrosion current density of 12.75 mΩ·cm 2 and 2.619 × 10 −6 A/cm 2, respectively. The influence of the phase composition, microstructure, and surface morphology on the anti-corrosion behavior and conductivity of the coating were analyzed in detail. Highlights: NbN coatings were deposited by multi-arc ion plating at various nitrogen partial pressures. The NbN coating deposited at a relatively high nitrogen partial pressure possessed better properties. The influence of the phase composition, microstructure, and morphology on the properties of the coated-SS were analyzed.