Anti-wear multilayer coatings based on chromium nitride for wood machining tools

The performed experiments revealed that the anti-wear resistance of chromium nitride and chromium carbonitride multilayer coatings obtained by the PVD method was higher than each of the phases separately. The CrN/CrCN coatings were obtained using cathodic arc evaporation. They consisted of seven modules, each approximately 400 nm thick, characterised by different thickness ratio of the CrN and CrCN layers in the modulus. A layer of chromium 0.1 μm thick was used as a sublayer. The adhesion of the coatings was determined using scratch test and Rockwell test. Hardness and stress as well as friction and wear coefficients when used to work timber were determined. Industrial milling tests of dry wood were carried out. The results of above measurements showed that the best useful properties were observed when the thickness ratio in coatings’ module was 2:1 which could be attributed to its very good adhesion to the substrate (about 115 N) and low wear rate. The tools with multilayer CrN/CrCN coatings improve the quality of the treated wood surface in comparison with uncoated knives.