Багатошарові леговані нітридні покриття системи TiAlN

The results of studies of the range of multilayer nanostructured coatings based on the TiAlN system - structural state, morphology, composition, and microgeometry of the interface - are presented. A coating with a total thickness of 7-8 μm and a layer thickness (TiAlN/CrN) of 20-30 nm was applied by the vacuum arc method to a base of superhard ceramics based on cubic boron nitride. The influence of doping of the coatings with Y, Y, and Si materials and a complex of elements such as Y, Zr, and Nb on the state of the interface was considered. For coatings with different levels of material doping, the presence of a droplet phase at the interface of the coatings and its effect on the defectiveness and surface roughness of the coatings were analyzed. It was found that the minimum amount of the droplet phase at the interface is inherent in (TiAlSiY)N/CrN, which is associated with the high thermal conductivity of the resulting coating. A large amount of the droplet phase is characteristic of the (TiZrNbYAl)N/CrN coating. The roughness of the interfaces of the coatings changes according to the amount of the droplet phase. The microhardness of the coatings was determined, the value of which is related to the presence of alloying elements in the material. The microhardness of the coatings can exceed the microhardness of the nitrides that make up their composition: the microhardness of the (TiAlSiY)N/CrN coating is 30.5 GPa, and that of the CrN nitride is 26 GPa. No chips or cracks were found at the interfaces of the studied coatings. Based on the analysis of the results of studying the interface of coatings by the method of sketch testing, the aggressive and cohesive mechanisms of coating destruction were established, depending on the nature of the alloying of their materials. The results of studies of the mechanical and tribological properties of coatings allow us to propose promising areas for the use of coatings in PcBN cutting tools.