SPECTROSCOPIC CHARACTERIZATION OF STAINLESS-STEEL SURFACES TREATED BY PLASMA

Stainless-steel substrates were surface treated then coated with thin amorphous hydrogenated carbon films that were deposited by CH4 plasma polymerization. The effects of these surface treatments were studied by x-ray photoelectron spectrometry, ion scattering spectrometry and Fourier transform infrared spectrometry. A few minutes of O-2 plasma treatment at a power density of 0.5 W cm(-2) was shown to modify strongly the surface composition of these substrates, with chromium present at the surface being transformed gradually, from Cr2O3 to CRO(3), before disappearing altogether. In contrast, NH3 plasma of similar power, but generated over a few seconds, cleaned and functionalized the surface. Both of these treatments proved to be highly efficient in promoting good carbon film adhesion to the substrate.