Study of the influence of elemental composition variability in MoCrN coatings on stability and wear resistance

Abstract

The paper presents the assessment results of the applicability of MoCrN coatings as wear-resistant protective coatings capable of withstanding extreme operating conditions associated with both exposure to aggressive environments and high temperatures typical for their use as thermal barrier anti-corrosion coatings for the protection of steel structures. The coatings were obtained using the magnetron sputtering method, by variation of the power of which high-strength coatings with different ratios of elements in the composition, the change of which ensures variability of resistance to external influences and corrosion processes, are obtained. During the tribological tests of the studied coatings, it was found that the displacement of chromium from the composition of MoCrN coatings due to its substitution by molybdenum results in enhancement of resistance to destruction and wear, as well as an increase in the stability of the coating surface as a result of tribo-corrosion tests associated with the simultaneous impact of an aggressive environment and a rubbing body. According to the obtained results of changes in the friction coefficient of the studied samples, it was established that a change in the elemental composition of the coatings leads to a more than 2–5-fold increase in wear resistance, both in the case of standard tribological tests and after tribocorrosion tests. Enhancement of the stability of coatings by alteration of the elemental composition by substitution of chromium by molybdenum leads to a growth in resistance to corrosion processes by more than 1.5–2 times, which indicates a positive effect of variation of the composition of coatings and an increase in their resistance to external mechanical influences.