Change of internal stress of carbon superhard condensates at a process of annealing

Superhard carbon coatings with thickness from 5 nm up to 10 μm were obtained by vacuum-arc deposition of carbon plasma on sublayers from stainless steels, titanium and silicon under the temperature from 50 up to 150 °C. Correlation dependences between conditions of formation of carbon condensates and change of internal stresses in them at a process of annealing in a range of temperatures from 200 up to 475 °C were examined. It was shown that the character of internal stresses changing at a process of annealing of carbon condensates had proof correlation with the parameters of deposition (the temperature of sublayer, duration of a pulse of discharge) and it could be used for identification of coatings and for control of their properties. It was determined that superthin layers of carbon obtained by impulse vacuum-arc method effectively protected a surface from oxidation in an atmosphere of air up to 425 °C. Researches of surface structures of coatings by use of scanning probe microscopy (SPM) were carried out. It was classified as fractal and an explanation of mechanism of change of internal stress value in carbon coatings at a process of annealing was given.