Mechanical and tribological behavior of W/WCN bilayers grown by pulsed vacuum arc discharge

This study investigates W/WCN coatings grown by means of a repetitive pulsed vacuum arc discharge while varying the substrate temperature from room temperature (RT) to 200 °C. The coatings were grown using a cathode with W (6N) and WC (6N) targets for the W and WCN layers, respectively, and an anode that contains stainless-steel 304 as a substrate. The films grown at RT and at 150 °C possessed a lower percentage of carbon obtained from energy dispersive spectroscopy. This characteristic was related to the hardness, the coefficient of friction and the adherence. These films also possessed the best mechanical and tribological properties. Several wear mechanisms were identified, such as delamination and plowing out of abrasive and adhesive particles.

► W/WCN coatings present high hardness and a good mechanical behavior.
► Mechanical and tribological properties of W/WCN are influenced by substrate temperature.
► The decrease in the carbon concentration of the W/WCN enhances mechanical properties.