RBS and XRD analyses of carbon-coated stainless steel plates

This study focused on understanding the strong adhesion between coatings, up to 20 μm thick, made from a pyrolyzed polymer (M2-48) and a stainless steel plate (316L). Using X-ray diffraction, no carbide phase was detected in the coating. However, iron was detected by Rutherford backscattering spectroscopy throughout the entire thickness of the carbon coating and even on their surface. The linear relationship between the logarithm of the Fe concentration and the number of layers sprayed to make the coatings would tend to indicate that diffusion is occurring during the pyrolysis procedure. It is assumed that the presence of Fe in the carbon coating, and therefore the lack of a discrete interface between the carbon coating and the stainless steel substrate, is responsible for the good adhesion properties. The structure of unsupported carbon films and fibres has been identified as turbostratic, typical structure found in carbon blacks and heat-treated phenolic resins.