Microstructure and Mechanical Properties of PVD Nanoncrystalline Layers

Abstract

This work presents the research results on the structure and mechanical properties of coatings deposited by PVD methods on the X40CrMoV5-1 hot work tool steel substrates. It was found that tested coatings have nanostructural character with fine crystallites, while their average size fitted within the range 10–15 nm, depending on the coating type. The morphology of the fracture of coatings is characterized by a dense microstructure. The coatings demonstrated good adhesion to the substrate, the latter not only being the effect of interatomic and intermolecular interactions, but also by the transition zone between the coating and the substrate, developed as a result of diffusion and high-energy ion action that caused mixing of the elements in the interface zone and the compression stresses values. The critical load LC2 lies within the range 66–85 N, depending on the coating type. The coatings demonstrate a high hardness (4000 HV).