Electrochemical micromachining of titanium microstructures in an NaCl-ethylene glycol electrolyte

摘要

Titanium and its alloys are widely used in the aerospace and biomedical industries owing to their outstanding corrosion resistance and good biocompatibility. Wire electrochemical micromachining (Wire-ECMM) is a promising method for fabricating titanium microstructures because of the absence of residual stress and tool wear. The electrochemical dissolution characteristics and polarization curves of titanium in aqueous and ethylene glycol-based electrolytes are obtained and analyzed. The effects of electrolyte anion species on electrochemical machining of pure titanium are experimentally evaluated. An NaCl-ethylene glycol electrolyte is selected to explore the influences of various process parameters on machining accuracy in ECMM. A rotary helical electrode is utilized to accelerate the removal of electrolysis products and thereby improve the refreshment of the electrolyte. Finally, titanium microstructures of high surface quality are fabricated with high precision using ECMM at a voltage of 11 V, a spindle rotation speed of 4000 rpm, a pulse frequency of 200 kHz, a duty ratio of 30%, and an electrode feed rate of 0.3 mu m/s.