Tribological properties of magnetron-sputtered TiC coatings

Tribological properties, including friction, wear, and hardness, as well as microstructure, have been investigated using a pin-on-disk configuration for TiC coatings with different kinds of interlayers (Ti, Cr and Mo) of different thicknesses. Both stainless steel and alumina pins were alternately used. The wear tracks and cross-section microstructure of the TiC coatings with different interlayers were further characterized by optical microscopy or scanning electron microscopy (SEM). It is found that inserting a Cr or Ti interlayer between the coatings and substrates improves the friction, wear, hardness, and elastic modulus of the coatings, but inserting a Mo interlayer had the opposite effect. The influence of different kinds of interlayers, their thickness, as well as the TiC coating thickness on the tribological properties of the coatings are discussed.