Tribological performance of TiN and TiCN coatings on a working tool steel

Although the applications of TiN and TiCN coatings are extensive, their mechanical and tribological properties are influenced by the substrates in which they are deposited. The present work is focused on the tribological performance of TiN and TiCN coatings on a working tool steel. Besides, adhesion and microhardness tests were carried out. The adhesion performance of both coatings resulted in class 1, according to CEN/TS 1071-8 standard, which allows observing the quality of adhesion. The composite microhardness was investigated by the analysis of relative indentation (beta). Pin-on-disk tests were performed in dry and lubricated condition at 100 A degrees C against tungsten carbide (WC). Low friction coefficients of mu(k) = 0.08 for TiN and mu(k) = 0.03 for TiCN were obtained in lubricated conditions. Wear mechanisms were analyzed by scanning electron microscopy (SEM). Abrasive wear was observed as the principal wear mechanism in dry condition, while in lubricated conditions wear signals seem to be scarcely noticeable.