"Mechanically prepared copper surface in oxidizing and non-oxidizing conditions".

In the present work surface roughness of copper samples after mechanical surface preparation processes (polishing, grinding, sand-blasting) and after exposure in non-oxidizing (high purity argon) and oxidizing (air) conditions at 700 and 750 °C have been evaluated by contact profilometer and by fractal analysis. Quantitative description of surfaces that are hidden from the sight of conventional methods is possible by fractal analysis, e.g. in the present work, the roughness of Cu 2 O/Cu boundary has been evaluated under oxide layer. It has been pointed out, that in both oxidizing and non-oxidizing conditions initial surface roughness of copper is affected by annealing at high temperature: at 700 °C surface roughness of polished and ground samples increased but at 750 °C decreased in comparison to surface roughness prior to heat treatment. For sand-blasted samples in both oxidizing and non-oxidizing conditions the lowest values of surface roughness parameters were obtained at 750 °C. It is then concluded that two phenomena are responsible for such effect: chemical reaction between copper and oxygen and surface diffusion of copper due to high temperature of annealing. Unlabelled Image • Surface of copper samples had been polished, ground and sand-blasted. • Surface roughness had been evaluated by contact profilometer and fractal analysis. • There are differences in roughness after annealing in oxidizing and non-oxidizing conditions at different temperatures. • Changes in roughness are caused by chemical reaction between Cu and O and surface diffusion of Cu at high temperature. [ABSTRACT FROM AUTHOR]