Self-lubricating CrVN Coating Strengthened via Multilayering with VN

To improve the mechanical properties of self-lubricating chromium vanadium nitride (CrVN) coatings, vanadium nitride (VN) is combined with CrVN to form multilayered CrVN/VN coatings through an in-line magnetron sputtering system. The strengthening effect of the period thickness on the mechanical and tribological properties is studied. X-ray diffractometer, low-angle X-ray reflectivity, scanning electron microscopy, atomic force microscopy, electron probe micro-analyzer and X-ray photoelectron spectroscopy are employed to characterize the microstructures and chemical composition. Nanoindentation and ball-on-disc tribo-tester are used in characterization of the mechanical and tribological properties. The CrVN/VN multilayer coatings demonstrate good lubrication property with coefficient of friction down to 0.23. Multilayering with VN, the hardness of CrVN jumps to 27.6 GPa with period thickness of 6 nm, which has an improvement of 5.1 GPa compared with that of 22.5 GPa from rule-of-mixture.