Search

Abstract: V and N co-doped diamond-like carbon (DLC–VN) composite films were deposited on cemented carbide substrates by pulsed bias arc ion plating. The effects of V and N contents on the structures and properties of the films were investigated by X-ray photoelectron spectroscopy (XPS), Raman spectra, grazing incident X-ray diffraction (GIXRD), transmission electron microscopy (TEM) and nano-indentation, respectively. The as-deposited films consist of a DLC–VN nanocomposite, where VN nanograins are embedded in an amorphous carbon matrix. The V and N contents have significant influences on the relative proportion of VN with respect to DLC. A proper concentration of VN nanocrystals in DLC induces even the formation of nano-diamond. The DLC–VN films have higher hardnesses than pure DLC films, which could be attributed to the nanocomposite structure. [Copyright &y& Elsevier]

Abstract: Pulsed bias arc ion plating was used to form Cr-nitride films on stainless steel as bipolar plate of proton exchange membrane fuel cell. Surface micrograph, film thickness, film composition, corrosion resistance, interfacial conductivity and contact angle with water of the sample obtained at the optimal flow rate of N2 were investigated. The atomic ratio of Cr to N was close to 2:1 and the CrN phase with crystal planes of (111), (200), (220) and (311) was found in the film. Potentiodynamic and potentiostatic tests showed that the corrosion resistance of the bipolar plate sample was greatly enhanced. The contact resistance between the bipolar plate sample and Toray carbon paper was about two orders of magnitude lower than that of 316L stainless steel. The contact angle of the sample with water was 95°, which is beneficial for water management in fuel cells. [Copyright &y& Elsevier]