Cathodic Arc Deposition of TiCN Coatings - Influence of the C2H2/N2 Ratio on the Structure and Coating Properties

Abstract

TiCN thin coatings with various different carbon contents were deposited using cathode arc evaporation of pure titanium in a mixture of N2and C2H2gasses at a constant pressure of 1.5 Pa. The analyses show a transition from a stoichiometric to a non-stoichiometric coating structure with an increasing C2H2content. Moreover, the increase in the acetylene in the gas mixture leads to a decrease in the crystal phase from pure polycrystalline to pure amorphous. Nanohardness changes from 30.4 to 4.4 GPa and the cohesive failure of the coatings is in the range of 61 - 72 N. The tribology is estimated by the Ball-on-Disc method and an Si3N4ball as the counterpart. The measured coefficient of friction is in the range of 0.2 - 0.56.