CHARACTERISTICS OF MATERIAL-SURFACES MODIFIED USING PLASMA-ENHANCED ION-BEAMS

Plasma-enhanced ion beams an used for the surface modification of carb on steel, stainless steel, and Al alloys samples. The morphology and t he microstructure of the treated surfaces of the samples is examined w ith an optical microscope and a scanning electron microscope. Microhar dness is measured on both the treated surfaces as well as the cross-se ctions. Indications are that during the ion bombardment craters are fo rmed and surface melting is produced on the sample surfaces. The effec t of the ion bombardment is limited to the surface layer of the sample s. The density, size and distribution of the craters formed on the irr adiated surfaces are related to the current density and the ion energy . Larger sized craters tend to be associated with higher ion beam ener gies. For the ion beam energies used in this study, there is a thresho ld current density for crater formation and surface melting. Some poss ible mechanisms for the crater formation and effects of the ion beam p arameters are discussed. (C) 1998 Elsevier Science S.A. All rights res erved.