Surface finish machining of medical parts using plasma electrolytic polishing

Biomanufactured parts, for implant or generally in-vivo use, have high requirements for surface properties. Depending on their field of application, not only smooth, but also well-defined surfaces, i.e. roughness parameters, must be set to allow for the respective functionalities such as optimal cell growth or minimal friction and wear. While for many parts mechanical polishing procedures are state-of-the-art, which are time-consuming and limited in their flexibility, established electrolytic polishing processes often incorporate aggressive media such as acids. Plasma electrolytic Polishing (PeP), a high-voltage process combining anode dissolution and plasma-chemical processes, can be considered a suitable alternative. The paper focusses on current investigations of PeP and shows application scenarios, also pointing out necessary development directions to introduce PeP to industrial biomanufacturing process chains.