A PROCEDURE FOR ELECTROCHEMICAL POLISHING OF AN ALUMINIUM SUBSTRATE TO OBTAIN A SPECULAR SURFACE THEREOF

摘要

The present invention concerns the removal/reduction of the directionality or anisotropy of a surface and making the surface specular on a substrate material consisting of aluminium or an aluminium alloy. The central process stages are: chemical polishing, chemical etching, preferably using phosphoric acid, and electrochemical polishing, preferably using phosphoric acid. Alternatively, the chemical polishing could be replaced by another chemical etching and electrochemical polishing. The present invention has made it possible to produce bright surfaces with good optical qualities on substrate materials of inexpensive Al alloys which may contain recycled aluminium. With the improved process, it is possible to achieve a considerable increase in brightness both relatively (from the starting material to the finished material) and absolutely.