Abstract
A process vacuum chamber is filled with a homogeneous plasma of glow discharge with electrostatic electron confinement, which is used for surface hardening of massive products. At the current of 2–20 A and the gas pressure ranging from 0.1 to 1 Pa the discharge voltage amounts to 350–500 V. When a bias voltage of 2 kV is applied to an immersed in the plasma hollow cylinder with a mass of 15 kg, electrical power spent on heating it by accelerated ions exceeds by an order of magnitude the power spent on the discharge maintenance. The massive cylinder is heated up to 700 °C for 15 min. When argon mixture with nitrogen (30%) is used, the nitriding for 3h results in an increase in the surface hardness from 400 up to 1000 HV50 and the nitrided layer thickness grows to ~100 μm. The nitriding rate is enhanced by a high degree of nitrogen dissociation due to decomposition by fast electrons and surface structural defects due to bombardment by high-energy ions.
Highlights
Ion nitriding is widely used for hardening the surface of different machine parts [1,2]
It was shown in [37], that due to hollow cathode effect based on the multiplication of fast electrons in the cathode sheath of glow discharge, quite homogeneous plasma can be produced at p = 0.01–1 Pa
The chamber is filled with a homogeneous glow of the discharge plasma (Figure 4)
Summary
Ion nitriding is widely used for hardening the surface of different machine parts [1,2]. It improves their corrosion [3,4,5,6,7], wear [8,9] and fatigue [10,11] resistance. The surface structural defects facilitate the nitrogen introduction into the product surface. It is easier for smaller nitrogen atoms to penetrate through those defects into the surface layer compared to bigger nitrogen molecules. An increase in the degree of nitrogen dissociation in the plasma [14]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
