The advantages of incorporating CrxC nanograins into an a-C:H matrix in tribological coatings

The main application problem of pure hydrogenated carbon coatings is their very low fracture toughness. However, their excellent tribological properties are extremely useful. The application of a-C:H as a matrix in nanocomposite coatings allows users to obtain materials which have moderate hardness, stiffness, good fracture resistance and retain their good tribological properties. Cr2C/a-C:H coatings deposited by magnetron sputtering under different acetylene gas flows were subjected to a wide range of mechanical and tribological tests. The effect of the coatings’ microstructure on hardness, as well as scratch, fracture and wear resistance, was studied. Such analysis was conducted to optimize the amount of ceramic nanograins in the coating and to design coatings based on a carbon matrix dedicated for use in self-lubricating friction nodes in the automotive, aerospace and tool industries.