Ceramic-metallic (TiN-Cu) nanostructured ion-plasma vacuum-arc coatings for cutting hard-alloy tools

The structure and properties of TiN-Cu coatings with a broad range of copper concentrations (C (Cu) = 0.6-20 at %), which were fabricated by the ion-plasma vacuum-arc deposition on a TT10K8B hard-alloy tool, including its cutting resistant tests, were investigated. The introduction of copper into the coating composition diminishes crystallites of the nitride phase from 100 to 20 nm. The hardness of coatings increases from 20 to 40 GPa, with an increase in C (Cu) to 7-8%. The further increase in the copper content, which is accompanied by diminishing crystallites of the nitride phase, is characterized by a decrease in hardness to 14-15 GPa, which is associated with the influence of soft plastic metal. Resistant cutting tests of steel 35KhGSA of removable multifaceted plates (RMP) with the TiN-Cu coatings indicate that the optimally selected composition (TiN-7-8 at % Cu) increases RMP resistance more than by a factor of 6 and 2.5 as compared with tools without the coating and with the TiN coating deposited according to the basic technology, respectively.