Composition, microstructure and properties of C-N-V films prepared by pulsed bias arc ion plating

High quality C-N-V films with different compositions were prepared on cemented carbide substrate using pulsed bias arc ion plating. The surface morphology, composition, microstructure and properties of C-N-V films were investigated by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Raman spectra, grazing incident X-ray diffraction, and nano-indentation, respectively. The results show that the deposited films were nanocomposite films with VN nanocrystalline phase imbedded within diamond-like carbon(DLC) amorphous matrix. The hardness and elastic modulus, which are closely related to the composition and structure of the film, first increase and then decrease with increasing V and N contents and have the highest values of 368 and 5697 GPa exceeding that of pure DLC film prepared under the same condition when nitrogen content is 204% and vanadium content is 218%. The variation of V and N contents has significant influence on the phase structure, relative concentration of VN crystalline phase and DLC amorphous phase, and induces the formation of nano-diamond phase, hence has great effect on the properties of the films.