Plasma Electrolytic Polishing – An Overview of Applied Technologies and Current Challenges to Extend the Polishable Material Range

Plasma electrolytic processes have gained attention from metal finishing industries due to their capability to considerably enhance surface properties. Especially, plasma electrolytic polishing is an innovative surface treatment resulting in very smooth, high-gloss surfaces with improved corrosion resistance. Although it has many advantages compared to electro polishing, just a few articles have been published in the field of plasma electrolytic polishing until now (mainly of stainless steel, titanium); the machining of other materials remains challenging. In this contribution, the authors provide an overview of plasma electrolytic polishing and describe new work in the field of polishing copper and its alloys. Transferring plasma electrolytic polishing to other metals and material geometries requires an adaption of the experimental conditions. To overcome this challenge a systematic methodology was developed. Several parameters, like electrolyte composition and complexing agents are investigated. Surface roughness as well as gloss was determined as function of processing time and voltage and compared to conventional electro polishing.