The oxidation behavior and tribological properties of Si-implanted TiN coating

TiN coating was deposited on cemented carbide (WC-TiC-Co) substrates by Magnetic Filter Arc Ion Plating (MFAIP). Si ions were implanted into samples with the doses of 5 × 1016 ions/cm2 and 1 × 1017 ions/cm2 at 40 kV by using Metal Vacuum Vapor Arc (MEVVA) ion source. After oxidation at different temperatures ranging from 550 to 700 °C, changes in the microstructure, oxides composition, hardness and surface morphology of the TiN coating were systematically characterized by glancing incidence x-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and Microhardness testing. It was found that the oxidation resistance of the TiN coating could be effectively improved by increasing Si ion doses due to the formation of an amorphous Si3N4 phase and Si ion implantation might improve the stabilisation of the anatase-TiO2 phase. The tribological properties were also investigated with a ball-on-disk tribometer. The results showed that the friction coefficient of TiN coating decreased remarkably after Si ion implantation and the wear mechanism for both un-implanted and Si-implanted TiN coating against GCr15 steel ball was adhesive wear. The Si-implanted TiN coating at dose of 5 × 1016 ions/cm had a lower friction coefficient as well as a better wear resistance.