Tamaño de fuente:
MECHANICAL AND TRIBOLOGICAL BEHAVIOR OF TITANIUM CARBIDE, ALUMINUM TITANIUM NITRIDE AND TITANIUM NITRIDE COATINGS DEPOSITED BY CATHODIC VACUUM ARC TECHNIQUE
Última modificación: 14-07-2016
Resumen
TiC, TiN and TiAlN coatings have been deposited by arc technique using temperatures of 50, 100 and 150° C to study the influence of this parameter on its mechanical and tribological behavior. The coatings were characterized in terms of cristalyne structure and thickness, using X Ray Diffraction (XRD) and Scanning Electron Microscope, respectively. The mechanical and tribological characterization includes: scratch test, wear test and nanohardness. On the TiN and TiC coatings the highest crystallographic density is shown at 100°C temperature, at this temperature of the substratum, the nucleation and the diffusion of the activated species are improved, due the greater atomic diffusion gradient, diminishing the grain boundaries and increasing the crystallinity of the coating [1]. For these coatings is observed that, the first to show failure is the TiC one , which is due to its low adherence, since the atomic interdiffusion between the substratum and the coating is not promoted , the friction coefficient is of 0.3 before the failure occurred at 5m of the path. The TiN showed a friction coefficient before the failure of the coating at 25m of the path, of 0.45, showing that the superficial treatment of the substratum improves the friction coefficient of the substratum. It was observed on the coatings of TiAlN an increment in the atomic percentage of Al, which presents a competition with Ti and structural changes with the temperature increase. The friction coefficient was of 0.3 for the TiAlN coating at 100°C. The size of the grain and the rugosity were influenced by this growth parameter [2]. It was observed that the coatings with concentrations of 25 % of Al approximately and 75% of Ti, showed an optimal blend of mechanical and tribological properties