Gradient PVD coatings deposited on the sintered tool materials

Purpose: The paper presents investigation results of properties of the sintered tool materials: cemented carbides, cermets and Al2O3 type oxide tool ceramics with gradient (Ti,Al)N and Ti(C,N) coatings deposited with the cathodic arc evaporation CAE-PVD method.Design/methodology/approach: Analysis of the mechanical and functional properties: surface roughness, microhardness, adhesion, and wear. Analysis of the structure (SEM). Computer simulation of stresses carried out in ANSYS environment, using the FEM method.Findings: The wear resistant gradient coatings of the type (Ti,Al)N and Ti(C,N) deposited on the investigated sintered tool materials yield a considerable increase of microhardness in the surface area, which, combined with good adhesion of the coating to the substrate, obtained in effect of the application of gradient structure of the coating, has the influence on the applicability properties of these materials during machining tests. A more advantageous distribution of stresses in gradient coatings influence on better mechanical properties. The distribution of stresses on the coating surface has the influence on microhardness, while distribution of stresses in the contact area between the coating and substrate has the influence on the adhesion of coatings.Practical implications: Deposition of hard, thin, gradient coatings on materials surface by PVD method features one of the most intensely developed directions of improvement of the working properties of materials.Originality/value: Techniques of gradient coatings deposition is one of the most spectacular aspect of the materials engineering development in the last years. Uunique combination of substrates and coatings is presented in the paper.