Analysis of the fundamental removal geometry in electrochemical profile turning with continuous electrolytic free jet

Abstract

Electrochemical machining applying a continuous electrolytic free jet (Jet-ECM) is a potential, non-conventional technique for micro-machining of electrically conductive work-pieces. The distribution of the current density is restricted to a confined area by the electrolyte jet, hence, highly localized removal geometries can be realized. In addition, very high current densities are possible, which lead to high surface qualities.Jet-EC machining of plane work-piece surfaces has been presented in several previous works. In this study, experimental analyses on the fundamental removal geometries in Jet-EC profile turning are carried out. The material of the work piece, the relative motion speed between the nozzle and the work piece surface, the working gap as well as the type and the electric conductivity of the electrolytic solution were chosen according to previous analyses on machining plane surfaces to allow for comparability.Thus, a work piece of 1.4301 stainless steel with a diameter of 3mm was used. The rotational speed was kept constant at a value of 6.37 / min, which represents a relative motion speed of 1mm/s between the nozzle and the work piece surface. The experiments were carried without absolute movement of the electrolyte nozzle at a constant working gap of 100μm. An aqueous solution of NaNO3 with a salt fraction of 30% was applied as electrolytic liquid. The electric potential was increased from 10V to 60V in order to determine the influence on the resulting removal geometry.Circumferential grooves were realized by Jet-EC profile turning on the rotation-symmetric specimen. The fundamental removal geometry will be compared to the results in Jet-ECM of plane work-pieces. It will be shown, that the applied voltage significantly influences the width and the depth of the grooves due to the influence on the current density.