Low-energy high-current plasma immersion implantation of nitrogen ions in plasma of non-self-sustained arc discharge with thermionic and hollow cathodes

This paper presents the results of low-energy high-current implantation of nitrogen ions into AISI 5140 steel. The plasma was generated using a plasma source based on non-self-sustained arc discharge, using thermionic and hollow cathodes. The influence of the temperature of the specimens and irradiation dose on the characteristics of the ion-modified layer was studied. The temperature of the specimens was controlled within the range of (450–650) °C by changing the duty factor of the bias pulse and the average ion current density. The microhardness of the steel after 1-hour of low-energy high-current implantation of nitrogen ions increased almost 2-fold (up to 7100 MPa), and a modified layer with a thickness up to 200 μm was formed. The wear resistance increased 7.5-fold. The main factor determining the efficiency of nitrogen dopant penetration was the temperature of the specimen. The parameters of the ion treatment influence the shape of the hardness distribution profile and the efficiency of ion cleaning of the surface. •AISI 5140 steel was treated by low-energy high-current implantation of nitrogen ions in gas-discharge plasma.•Mechanical and tribological characteristics, structure and elemental composition of modified layers are presented.•500 °C treated specimen showed the best results of hardness and wear resistance.•The specimen temperature was set by changing the bias duty factor without change in its amplitude and maximum current.