CrC and NbC carbide coatings both have good mechanical properties, wear resistance, and corrosion resistance. The present study seeks to combine the two coating systems in order to further enhance their properties. NbCrC_x and NbCrC_xN_y coatings (where x and y denote the atomic percentages of carbon and nitrogen, respectively) were deposited on SKH51 substrates using a radio-frequency unbalanced magnetron sputtering system. The mechanical, tribological, and corrosive properties of the coatings were investigated and compared. Among the NbCrC_x coatings, the NbCrC₆₁ coating showed high levels of hardness, excellent adhesion strength, and good wear resistance. Among the NbCrC_xN_y coatings, the NbCrC₅₅N₅ coating showed high adhesion strength and hardness and excellent tribological properties. However, for nitrogen contents greater than 16 at%, the adhesion strength was dramatically reduced, resulting in poor tribological performance. Among all of the coatings, the NbCrC₄₉ coating showed the best corrosion resistance due to its enhanced crystallinity, high adhesion strength, moderate surface roughness, and high sp³ C-C bonding ratio.

CH _x -TiNbAlN coatings were deposited on WC turning tools and silicon wafers using a radio frequency unbalanced magnetron sputtering system with acetylene fluxes in the range of 4 to 12 sccm. The hardness of the coatings decreased with an increasing acetylene flux. By contrast, the H/E ratio increased as the acetylene flux increased and reached a value of 0.097 for the CH ₁₂ -TiNbAlN coating. The CH ₁₂ -TiNbAlN coating was found to improve the wear resistance of the turning tool by around 15% compared to that of an uncoated tool.

NbC _x coatings were deposited on SKH51 substrates by RF magnetron sputtering with different acetylene fluxes. The XRD analysis results showed that the crystalline structure of the coatings changed from NbC phase to amorphous phase as the acetylene flux increased. The coating hardness decreased, whereas the adhesion strength increased, with an increasing carbon content. The average friction coefficient of the coatings decreased as the carbon content increased. The coating deposited with an acetylene flux of 8 sccm showed the highest H/E ratio (0.073) and adhesion strength (HF 1) of all the coatings. Consequently, the coating exhibited the best tribological properties, including the lowest friction coefficient and lowest wear depth and wear rate, under normal loads of 2, 5 and 8 N, respectively.