Tribological behaviors of titanium nitride-and chromium-nitride-based physical vapor deposition coating systems

This study investigates the effects of the deposition process and coating composition on microstructural and tribological properties of TiN-and CrN-based coating systems. Coatings were produced using various PVD-based processes-electron beam (EB), cathodic arc (CA), and plasma enhanced magnetron sputtering (PEMS). All coated samples were evaluated for their composition, microstructure, and surface morphology. Coating mechanical properties such as hardness, Young's modulus, and coefficient of friction were also studied and related to their microstructures, wear, and erosion resistances. It was found that hardness (H), Young's modulus (E), and coefficient of friction had impact on both wear and erosion rates. In particular, the H 3/E 2 ratio was inversely proportional to the specific wear rate. For erosion behavior, higher H 3/E 2 ratios relate to lower erosion rates at low impingement angles, whereas higher H 3/E 2 ratios relate to higher erosion rates at high impingement angles. © 2012 American Society of Mechanical Engineers.