Binary nitride and oxynitride PVD coatings on titanium for biomedical applications

The aim of this study was the development and characterization of wear resistant and adhesive (oxy-)nitride refractory metal PVD coatings for biomedical applications. The steered arc technique with a special sector target was used to vaporize two different metal components. The subjects of investigations were layers of (Ti,Zr)N, (Ti, Nb)N and (Ti, Nb)ON with an average thickness of approximately 3–4 μm. By means of the sector target, the zirconium content of the (Ti,Zr)N layers could be varied between 50% and 70%, and the niobium content of the (Ti,Nb)N layers between 30% and 40%. X-Ray diffraction analysis showed for all materials that the cubic TiN lattice structure still dominates while a part of the titanium atoms are successively substituted by the second metal component, Zr and Nb, respectively. An excessive insertion of oxygen at interstitial sites leads to an embrittlement of the resulting coatings. All investigated coatings showed a preferred growth in the (111) direction of the cubic lattice.