In situ investigation of the internal stress within the nc-Ti2N/nc-TiN nanocomposite coatings produced by a combined magnetron sputtering and ion implantation method

Abstract

The structure, thickness and adhesion to the substrate of the hard coatings used for protection against wear and corrosion are very important characteristics and they are strongly dependent on the internal stress induced into the coating during its growth. Development of a new class of coatings with a hardness of 2500–4500 HV0.1 and a thickness of 10–50 μm might increase significantly the application area of PVD coating in hydraulics, automotive, forming and even cutting tools. An ion assisted deposition method that combines magnetron sputtering and ion implantation (CMSII) as simultaneous processes has been used to produce nc-Ti2N/nc-TiN nanocomposite layers with such properties.In this paper, the cantilever method was used for in situ monitoring of the internal stress during the coating deposition. Generally, the internal stress produced by CMSII method is about half of that produced by magnetron sputtering without ion implantation. The structure of these coatings were analyzed by means of TEM. The adhesion and fracture properties of the coatings were analyzed by a mini version of a tensile test.