Influence of heat treatment on the structure and mechanical properties of carbon coatings doped with zirconium and silicon

It has been established that during nitriding of carbon coatings alloyed with silicon and zirconium, the formation of compounds of the CN$_x$, C – Zr, Zr – N, Si – C, SiOх, Zr – O type takes place, and the degree of structural ordering of sp$^2$-clusters increases. At a heating temperature of up to 350$^\circ$C, the processes of coating graphitization occur due to nitrogen desorption with simultaneous rupture of C = N bonds, which ensures better thermal stability of hardness and elastic modulus compared to non-nitrided coatings. At the same time, the values of friction coefficients and volumetric wear coefficients of the counterbody during heat treatment up to 350$^\circ$C increase due to the abrasive effect of solid carbide phases, a further increase in the heat treatment temperature up to 500$^\circ$C leads to an improvement in the tribotechnical characteristics of the coatings due to a more intensive formation of graphite clusters, which act as a solid lubricant.