Microstructure and mechanical properties of Cr-V-C-N films

Quaternary Cr–V–C–N films were deposited on Si wafers through a hybrid system of arc ion plating and sputtering techniques in an Ar/N2/CH4 gaseous mixture. In this work, the effects of vanadium on the microstructural evolution, mechanical properties and friction mechanism of Cr–V–C–N films were investigated. The results showed that quaternary Cr–V–C–N films consisted of nanosized crystallites of (Cr,V)(C,N) and amorphous VCN phases. The Cr–10·4 at-%V–C–N film possessed the higher hardness value of 34 GPa, compared to the 27 GPa of a Cr(C,N) film. Additionally, the friction coefficients of the Cr–V–C–N films were reduced from 0·38 for the Cr–C–N film to 0·27 for the Cr–10·4 at-%V—C–N film. Atomic force microscopy (AFM) and Auger electron spectroscopy (AES) analyses also revealed that the amorphous phase VCN phases played a role in reducing the friction coefficients of the films. The a-VCN phase (vanadium rich) was believed to cause a tribochemical reaction with ambient air during the wear process.