Effect of Cr Doping on the Microstructure and Tribological Performances of Graphite-like Carbon Films

Graphite-like carbon ( GLC ) film and graphite-like carbon film doped with Cr ( GLC-Cr ) were fabricated successfully using magnetron sputtering technique. The structure and mechanical properties that GLC and GLC-Cr films were characterized by field emission scanning electron microscopy,Raman spectroscopy,X-ray photoelectron spectroscopy and nanoindentor. The tribological performance in different environments of films were investigated by UMT-3 multi-functional tribometer. Experimental results indicated that,compared with the pure GLC film,the content of sp² bonds in graphite-like carbon films were increased and the hardness was decreased. And the tribological properties of graphite-like carbon film was improved significantly in three different environments by using Cr as dopant. The friction coefficient of GLC and GLC-Cr films decreased in the presence of water. However,the volatility of friction curve and wear rate were all the lowest and exhibited more excellent self-adapted friction reducing and antiwear properties under the environment of oil.