Jet Application of Plasma Electrolyte Polishing

Plasma electrolytic polishing (PEP) has been gaining increased attention as a replacement for electrochemical polishing (EP) processes. It significantly enhances metal surface properties in terms of surface roughness and corrosion resistance. In contrast to EP, PEP does not require any preliminary workpiece cleaning or treatment with hazardous acids. However, PEP in bath applications yields inhomogeneous polishing results and, in particular, cannot polish more complex geometries such as cavities. To overcome these issues and to enhance the control of local polishing effects on metal workpieces, the use of a PEP jet is investigated. A jet configuration enables higher PEP control and increases PEP polishing rates by a factor of six compared to a polishing bath as a result of higher localized current.