Surface hardening by means of plasma immersion ion implantation and nitriding in glow discharge with electrostatic confinement of electrons

Moscow State University of Technology “STANKIN”, 1 Vadkovsky per., 127994 Moscow GSP-4, Russian Federation

^a Corresponding author: yumelnik@mail.ru

Received: 27 September 2015
Accepted: 19 October 2015

Abstract

At argon or nitrogen pressure 0.005–5 Pa a metal substrate is immersed in plasma of glow discharge filling a vacuum chamber and negatively biased to U = 1−10 kV. Emitted by substrate secondary electrons bombard the chamber walls and it results in growth of electron emission chamber walls and rise of gas ionization intensity inside chamber. At pressure p< 0.05 Pa nonuniformity of plasma density does not exceed ~10%. Measurement results of sheath width d between homogeneous plasma and a lengthy flat substrate were used to calculate dependence of the ion current density j_i on its surface and ion-electron emission coefficient γ_i. The dependence allows evaluation of average dose of ion implantation on any complex-shaped product of the same material.