The Study Of Tribological Properties Of Nitride And Carbide Based Films In Different Water Environmen

DLC (a:C-H) films with 1μm thickness were deposited by ion beam deposition, TiAlN films and CrN films with 2μm thickness were deposited by enhanced magnetron cathodic arc deposition. The mechanical properties of these films were evaluated by nano-indenter. The tribological properties of coatings in water were evaluated using ball-on-disk tribometer. The microstructure and composition of films were observed and analyzed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The worn surface on balls and films were observed by optical microscope and three-dimensional profilemeter, respectively. The results showed that the DLC films against SiC ball and Al₂O₃ ball had a low friction coefficient below 0.08, while the DLC film peeled off. However, when sliding against SUS440C ball and SUJ2 ball, the DLC film kept well and had a high friction coefficient about 0.12. The specific wear rate of balls and disks varied in the scale of 10^-7mm³/Nm to 10^-8mm³/Nm for DLC/ SUS440C in water, while the value was in the scale of 10^-7mm³/Nm for DLC/SUJ2. The wear mechanism of DLC/SUS440C and DLC/SUJ2 in water was adhesive wear and abrasive wear. The DLC film was worn severely in cutting fluid and 20% glycol. Compared with the deionezed water, sea-water, and cutting fluid, the TiAlN/SiC in 20% glycol had the lowest friction coefficient 0.34 and the TiAlN film had the lowest specific wear rate 1.41×10^-7 mm³/Nm. While the largest specific wear rate of SiC ball (6.684×10^-7 mm³/Nm) was also obtained in 20% glycol. When TiAlN coating sliding against SiC ball in deionized water at defferent test parameters, the specific wear rates of disks and balls varied in the scale of 10^-5mm³/Nm to 10^-6mm³/Nm and 10^-6mm³/Nm¹0^-7mm³/Nm, respectively. The specific wear rates of disks were higher than balls'. The specific wear rate of TiAlN coating was not increased linearly with an increasing of sliding distance, the wear mainly occurred in the initial stages. The wear mechanism of TiAlN/SiC tribo-pair was adhesive wear, abrasive wear and brittle spalling. In cutting fluid, the DLC film owned the lowest specific wear rate and the lowest friction 0.067.