A general model for vacuum condensates and vacuum diffusive coatings

Abstract The paper suggests a general model for the classification of metal coatings obtained in vacuum. The model gives the thickness, the bond character and the bond to the coated substrate, depending on : temperature, forming time and condensation rate. The coatings have been classified in two basic groups : vacuum condensates and vacuum diffusive coatings, separated by a layer zone having an intermediate character. The model is presented graphically and a prognosis is made on the change in thickness of the coating of each group, changing the technological parameters. The model suitability is tested for coatings obtained in a vacuum furnace by magnetron sputtering of a ferro-chromium target in a neutral medium by the method of plasma vacuum diffusive metallizing in element sputtering conditions (PVDM-E) on steel substrates with a composition (12%Cr; 1.5%C; 0.5%Mo), in the temperature range 850–1000 °C and a process duration of 60–120 min for two condensation rates. The thickness, the structure and the phase composition of the coatings are presented by the three-coordinate figures. A classification has been made, according to the suggested general model.