Influence of niobium ion implantation on the microstructure, mechanical and tribological properties of TiAlN/CrN nano-multilayer coatings

Nb ion irradiation induced amorphization and the formation of nanocomposite and nanocrystalline in the coatings surface. Nb ion implantation resulted in the formation of NbN, Nb2O5 and a small fraction of niobium oxynitride in the implanted zone. The nanohardness and the H3/E*2 ratio of the coatings increased remarkably, which was due to the resulting structure and the formation of NbN phases in the implanted zone caused by energetic Nb ion implantation. Nb ion implantation could effectively improve the tribological performance of TiAlN/CrN coatings, which was due to a lower friction coefficient and the increasing of the hardness and the plastic deformation resistance of the coatings. The amorphous top layer formed on the surface could act as a solid lubricant during the wear sliding.