TRIBOLOGICAL BEHAVIOR AT ELEVATED-TEMPERATURES OF THIN PHYSICAL VAPOR-DEPOSITED COATINGS

TiCN, WTiN, TiCON and silver-TiN hard coatings were deposited on high speed steel substrates by d.c. magnetron sputtering. The roles of the temperature and normal load were investigated for non-coated high spee d steel discs against tungsten carbide pins using a pin-on-disc tribom eter in order to establish the friction parameters. The friction coeff icient and wear resistance of samples coated with thin films were meas ured at 500 degrees C in air. The pins were made of uncoated tungsten carbide. The tribological results for the different coatings were comp ared. It is shown that the friction coefficient is not decreased by th e coatings and has a very high value (between 0.9 and 1.1). However, t he wear resistance increases especially for the silver-TiN coating.