Microstructure and properties of a-C films deposited under different argon flow rate on stainless steel bipolar plates for proton exchange membrane fuel cells

Amorphous carbon (a-C) film is deposited to improve the corrosion resistance and interfacial conductivity of stainless steel bipolar plates in proton exchange membrane fuel cells. Argon flow rate significantly influences the atoms free path and bias ions current drawn at the substrate and thus to modify the microstructure of a-C films. Therefore, this study aims to investigate the effects of argon flow rate on compactness, microstructure, corrosion resistance and interfacial contact resistance of a-C films comprehensively. The lowest contact resistance and corrosion current density are 1.3 m Omega cm(2) and 0.1 mu A/cm(2), respectively, which is much lower than the technical target and previous studies. At last, the enhancement of corrosion resistance and interfacial conductivity of a-C films are discussed. The promising results are shedding new light on the deposition mechanism of a-C films applicable for proton exchange membrane fuel cells.