Tribological behavior and wear mechanisms of Ti-C : H/TiC/TiCN/TiN/Ti coatings when sliding against steel, bronze and aluminum alloy rods

Abstract

Tix%-C : H coatings of differing thicknesses and with various titanium concentrations were deposited on tungsten carbide disks by unbalanced magnetron sputtering. The mechanical properties, microstructure, and adhesion strength of these coating were measured. The tribology properties of the coatings against AISI 1045 steel, AA7075, AA6061 aluminum alloy, and bronze rods were tested by an oscillation sliding test machine with a line-contact wear mode under dry conditions. The microhardness of Tix%-C : H coatings increased with an increasing Ti concentration. The optimum coatings are composed of an intermediate layer of TiC/TiCN/TiN/Ti and a top layer of Tix%-C : H with x ≤ 20%. These coatings have an excellent wear resistance and a low friction coefficient when paired with a carbon steel or copper alloy. These pairs are marked by the mildly wear of the counterbodies of AISI 1045 steel and bronze. The coatings are less suitable for oscillation with the aluminum alloy under dry conditions due to severe adhesion damage.