Effect of carbon on TiAlCN coatings deposited by reactive magnetron sputtering

TiAlCN coatings with various carbon contents have been prepared by direct current reactive magnetron sputtering using Ti–Al–C mosaic type targets. The composition and structure of the coatings were analyzed by energy dispersive spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman spectroscopy. The micro hardness and tribological performance were measured by micro Vickers tester and ball-on-disc tester, respectively. It was found that the carbon concentration has a significant effect on the microstructure evolution of the coatings. The hardness of TiAlCN coatings increases and then decreases as the carbon content is increased. Coating prepared by a target with 50 vol.% graphite reaches the maximum hardness(2443 HV25g). Coating with a maximum hardness and lowest friction coefficient was obtained by optimizing the carbon content. The relationships of structure–property–performance by carbon modification were discussed.