Influence of the thickness of the bilayer TiN / ZrN on structure and properties of the multilayer coating obtained by vacuum-arc evaporation

Phase composition, structure, substructure, hardness and elastic modulus of vacuum-arc multilayer coatings of TiN/ZrN, obtained with different thicknesses bilayer periods at constant negative bias potential (U_b) -140 and -200, was investigated by X-ray diffraction, electron microscopy and microindentation. It is established that under the action of these potentials during the deposition of layers mononitrides ZrN and TiN formed the preferred orientation of crystallites (texture) with the [111] axis perpendicular to the plane of growth. Increasing the number of boundaries with decreasing thickness of periods leads to increased hardness of 45 GPa, which is much greater than the hardness as ZrN and TiN single-layer coatings