REACTIVE DEPOSITION OF ALUMINUM IN A NITR OGEN ATMOSPHERE ON XC-70 STEEL SUBSTRATES - EFFECT OF PRESSURE AND NITROGEN FLOW ON MEAN CRITICALDISCHARGE

The paper presents the results obtained by reactive radiofrequency spu ttering deposition of aluminium onto XC 70 steel in an nitrogen atmosp here. The samples were scratch tested and the influence of the work pr essure and the gas flow on the critical load values was measured to de termine the experimental conditions leading to the best results. XPS a nd SEM analyses of the coating have been made and have shown that the mean critical load is highly influenced by these parameters since ther e is a modification in the composition and structure of the film. In a ddition, the mechanisms of crack propagation are analysed and the cond itions responsible for the failure of a cone are discussed.