Mechanical and Tribological Properties of Carbon-Based Graded Coatings

The paper presents research on coatings with advanced architecture, composed of a Cr/Cr2N ceramic/metal multilayer and graded carbon layers with varying properties fromCr/a-C:H to a-C:N. The microstructure of the coatings was analysed using transmission electron microscopy and Energy Dispersive Spectroscopy, the mechanical properties were tested by nanoindentation, spherical indentation, and scratch testing, and tribological tests were also conducted. The proper selection of subsequent layers in graded coatings allowed high hardness and fracture resistance to be obtained as well as good adhesion to multilayers. Moreover, these coatings have higher wear resistance than single coatings and a friction coefficient equal to 0.25.