Influence of the Intermediate Layer on the Adhesion and Friction of Titanium-Based Nitrided Coatings on a Copper Substrate

The structure, phase composition, adhesive and tribological properties of TiN coatings deposited on copper by cathode-arc deposition have been studied. The effect of intermediate layers of Cu+Ti and NiCr on the phase composition and adhesive properties of coatings has been studied. During scratch testing of coatings, it was found that an increase in the load on the indenter leads to deformation of the copper base. In this case, the TiN coating on the Cu+Ti sublayer does not destruct until the end of the tests, only transverse cracks appear on the coating at a load of ~35 N. The TiN coating on the NiCr sublayer begins to crack at an indenter load of ~23 N, and at a load of ~26 N, the coating peels off. These results indicate that the Cu+Ti intermediate layer provides a higher adhesive strength of the coating to the substrate than the NiCr sublayer. X-ray phase analysis showed that the use of intermediate layers of Cu+Ti and NiCr leads to different types of X-ray patterns of the Ti-N coating, which may be due to the type of texture formed in the coating on different intermediate layers. During tribological testing of coatings on a copper substrate with intermediate layers of Cu+Ti and NiCr, friction coefficients were determined that behave stably over time.