Structure and mechanical properties of a-C coatings deposited from pulse carbon plasma on a ni heated sublayer

The features of the morphology, phase composition and mechanical properties of the carbon coatings deposited from pulsed flows of carbon plasma onto the substrates containing nickel sublayers are determined when its temperature changes to 350$^\circ$ C. It has been established that heat treatment of Ni sublayers has a slight effect on hardness and elasticity modulus, leading to an increase in roughness RMS by 1.75 times and a more than 4-fold increase in grain size. The phase composition of Ni / a-C coatings deposited on heated nickel sublayers is characterized by a higher density of Csp$^2$ clusters, and with increasing heating temperature of the substrate, a significant decrease in roughness occurs. Using the method of instrumental nanoindentation, the structural and phase heterogeneity of coatings was established, which manifests itself in a non-monotonic change in the elastic modulus and a significant decrease in hardness with increasing indentation depth.