Surface modification by cathode spots of a vacuum arc

Cathode spots of a vacuum are have smart property to remove oxide on the metal surface selectively. Analyses of the surface treated by vacuum are revealed that various interesting surface modifications occurred during the removal of oxide. The authors have investigated these effects to open new application of the vacuum are. The cathode spots can remove inclusions which often cause surface defects. They attack not only oxide but also carbide inclusions and eliminate them from the surface by evaporation. Dry cleaning to remove the organic compound can also be possible. Degreasing (removal. of grease) proceeds in parallel to the removal of oxide. The vacuum are treatment results in the remarkable increase of hardness in the surface layer due to the rapid heating and quenching.