Properties of the multi-layer Ti/CrN and Ti/TiAlN coatings deposited with the PVD technique onto the brass substrate

The paper presents examination results of structure, corrosion resistance, changes of the coating constituents’ concentration and mechanical properties of the CuZn40Pb2 brass coated with the thin Ti/CrN and Ti/TiAlN 1, 15 and 150-ply multi-layer coatings. It has been demonstrated that the increase of the number of layers in the coating results in the several times greater corrosion resistance of the coated elements. The investigated elements demonstrate a good adhesion of the coatings to the brass substrate. The optimum mechanical properties have been obtained for the single-layer coatings with a thin pure Titanium interlayer used for stress reduction and limiting the crack propagation at the coating–substrate boundary, however, the increase of the number of layers to 15 or 150 results in their deterioration. It has been shown, simultaneously, that it is not possible to develop a “universal” coating and analysis of the operation conditions will influence mainly its selection and employment.