Carbon Based Coatings with Improved Fracture and Wear Resistance

The paper presents the results of mechanical and tribological tests of two kinds of carbon coatings with advanced microstructures - nanocomposite CrC/a-C:H and multilayer TiN/Ti/a-C:H. The introduction of barriers for dislocation motion and microcrack propagation as CrC nanograins in nanocomposite coating or Ti and TiN interlayers in multilayer led to coatings hardening and improved fracture and wear resistance in comparison to a single amorphous a-C:H coating. It was confirmed by wide range of mechanical tests. The mechanism of microcrack deflection and splitting on CrC nanograins and Ti layers was studied using spherical indentation tests and TEM observations of indent cross-sections.