Industrial scale manufactured superlattice hard PVD coatings

Superlattice hard PVD coatings exhibit high hardness values up to 60 GPa, wear resistance, and excellent protection against corrosion depending on the choice of the material partners involved. TiAlN/CrN, TiAlN/VN, TiAlYN/VN, TiAlN/ZrN, and CrN/NbN superlattice coatings with typical periods λ of 3-4 nm have been produced economically under production conditions in industrial sized coating equipment. Some of the coatings are characterised by high compressive stresses up to 10 GPa. In such cases the utilisation of the combined cathodic arc/unbalanced magnetron deposition method (arc bond sputtering technology) in combination with the introduction of a lower stressed monolithically grown base layer provides a sufficiently high bonding strength at the interface. The major deposition steps are: (1) pump down and preheating; (2) bombardment of the substrate surface with multi-ionised metal ions generated in a steered cathodic arc discharge; (3) deposition of a base layer (0·1-0·2 μm) using the unbalanced magnetron; (4) deposition of the superlattice coating with simultaneously operated unbalanced magnetrons or a combination of simultaneously operated unbalanced magnetrons and steered cathodic arc sources.