Investigation of stable boundary conditions for the Jet-electrolytic Plasma Polishing (Jet-ePP)

Abstract

Jet-electrolytic Plasma Polishing (Jet-ePP) is a modified form of Bath-ePP to selectively polish and clean local areas with lower-power. When Jet-ePP is used, it must be taken into account how the changed boundary conditions and the additional electrolyte jet parameters influence the basic process. It can be assumed that the plasma polishing changes into electrolytic polishing due to changed boundary conditions, which is not desirable. The non-existent closed boundary conditions must be compensated by setup adjustments. Changes in the phenomenological model of the removal are necessary.The paper shows how the additional and changed process parameters such as fluid flow, distance between anode and cathode influence the individual process phases. Current-time curves are used to investigate the changes in ignition and polishing phases, which are influencing the machining results. Due to these combined data it is possible to find stable process windows. For special changes of the phenomenological model, the physical changes have to be described.To compare the electric parameters such as the voltage drop over the electrolyte of both processes: Jet-ePP and Bath-ePP, equivalent circuit diagrams are used. These describe which changed conditions also lead to the formation of a plasma layer and produce the same effect as in Bath-ePP. In combination with the geometric proportions and the function of the workpiece, the most suitable scientific and industrial application areas are pointed out, making use of the localized jet in comparison with the well-established Bath-ePP process.