Yakushchenko I. Structure characteristics and physical and mechanical properties of multicomponent nitride coatings before and after ion implantation

The thesis is devoted to investigation of the influence of ion implantation by negative ions Au- on the phase composition, structure-stress and defect state, mechanical and trybological properties of five- and six- elements nitride coatings (TiZrAlYNb)Nx and (TiZrHfVNbTa)Nx, and influence on them of the deposition parameters – pressure of working state, and substrate bias voltage. The results of the investigation of element, phase and structure-deformated state of the coatings show that, two main crystalline phases are formed in the coatings – FCC and BCC; depending on the working gas pressure phase state is changed from amorphous to nanocrystalline; and coatings are under the compressive stress. Ion implantation by one-charge negative ions gold Au- leads to the following. Subsurface layer is disordered a lot, and has higher rate of BCC phase. Investigation of mechanical and trybological properties of the coatings showed, that increasing of hardness of the coatings in the implanted layer (up to 39,05 GPa), and index of viscoplasticity increasing to 0,123 takes place. Wear resistance is increased (up to 2,5 times), and friction coefficient is decreased, thus leading to improving of physical and mechanical properties of the investigated coatings (TiZrAlYNb)Nx and (TiZrHfVNbTa)Nx. Key words: vacuum arc deposition method, high-entropy alloys, ion implantation, negative ions, microstructure, point defects.