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The design and application of hard and superhard (H ≥ 40 GPa) coatings and their properties are discussed with the focus on superhard nanocomposites. The main part of the article deals with examples of industrial applications of hard and superhard nanocomposite coatings as wear protection coatings on tools for machining, forming, stamping, injection molding and the like. The advantages and possibilities as well as the limitations of the different types of coatings with emphasis on the nanocomposites are discussed and illustrated by a number of examples from aerospace and other branches of industry.

The development of novel superhard nanocomposite, nano-layered coatings and of the coating technology based on vacuum arc evaporation from rotating electrodes is summarized. The nc-(Al 1−x Ti x )N/a-Si 3 N 4 coatings in which the nanocrystals of the Al-rich solid solution with the fcc crystal structure of TiN are imbedded into a thin matrix of amorphous silicon nitride show high thermal stability, oxidation resistance and excellent performance in dry, fast machining that is superior to the state-of-the-art (Ti 1−x Al x )N coatings.

Novel superhard wear resistant nanocomposite coatings nc-(Ti1-xAlx)N/a-Si3N4 for advanced machining tools were developed and introduced into large scale industrial production within a relatively short time. We describe the development of the coating technology based on vacuum arc evaporation from a specially designed cylindrical cathode and, as a result of that development, the improvement of the properties and machining performance of the coatings.