Surface Modification of Steel by High Energy Nitrogen Ion Implantation

Abstract

Effects of high energy (MeV) nitrogen ion-implantation in surface layer of steel were investigated. The steel samples were ion-implanted with nitrogen ions accelerating to energies of 1.5, 3.0 and 4.5 MeV at a dose of 8×10¹⁷ ion/cm² by a tandetron accelerator system. The depth profiles of nitrogen implanted samples were analyzed by secondary ion mass spectroscopy (SIMS) . The nitrides formed by MeV ion implantation of nitrogen were studied using X-ray photoelectron spectroscopy (XPS) .The hardness and the wear resistance of implanted steels were measured by the Vickers hardness testing and the ball-on-disk wear testing. The profiles show that carbon layers were formed on surfaces of implanted samples and nitride layers were formed under near surface. The hardness for each load in the implanted samples were affected by the ion energy. The wear resistance was improved by the nitrogen ion implantation.