The influence of ion implantation parameters on the surface modification of steels

Ion implantation of steels and Co-cemented tungsten carbide has been shown to result in significant improvements in their resistance to abrasive and adhesive wear. Most of the laboratory tests so far have been carried out with implanted nitrogen and the results have been confirmed by a large number of industrial trials. This paper reports the results of the first part of an experimental program to determine the relationships between machine parameters during nitrogen ion bombardment and the observed retention and profiles as well as the corresponding improvement in the wear behaviour. To date we have determined the influence of varying independently the beam current density, sample temperature, target chamber base pressure and nominal dose of implanted nitrogen. Three materials were chosen for investigation: pure iron, NSOH tool steel and 18/8/1 stainless steel. Some information on the chemical composition near the surface of the implanted samples has also been obtained using XPS and CEMS analysis. (orig.)