Ion bombardment as a tool to modify surface properties of different materials

Abstract

A recently started project at Studcvik Energiteknik AB is concerned with the effect of ion implantation in different materials. Fundamental physical processes, leading to the observed surface modifications, as well as more application-oriented problems are studied. The materials investigated so far have been different kinds of carbon steels and some polymer materials (polymethyl methacrylate, polypropylene, polyethylene). Ion energies between 10 keV and 1.8 MeV have been studied. For metals, mostly energies of 70 keV N+ ions have been utilized, but ion irradiations have also been performed with He+, C+, O+ and Ar+ ions. Surface modification due to the ion bombardment has been investigated by different kinds of surface analyses (AES, RBS, SEM, IRS, ERS etc.) and characterisation of surface properties such as corrosion, friction, hardness, changes of erosion and chemical activity, formation of carbonyl bands and free radicals have also been carried out. In some cases drastic changes of surface properties have been observed. Many authors in the field have reported on the profitable influence of surface contamination from diffusion pump oil on tribological properties. In the present work we have initiated systematic and controlled studies on the influence of vacuum carbonization during ion implantation of metals. Experimental results as well as short discussions of possible mechanisms responsible for the observed surface modifications, are presented in the paper. © 1988.