Improving machining accuracy in wire electrochemical micromachining using a rotary helical electrode

Abstract

Wire electrochemical micromachining (WECMM) is becoming more important in fabricating complex microstructures. The machining accuracy of WECMM is usually evaluated by the interelectrode gap width. Faster electrolyte refreshment increases the uniformity of the electrolyte electrical conductivity distribution in the machining gap, the machining stability and the machining accuracy. We propose a method of WECMM using a rotary helical electrode that improves the machining accuracy by increasing the electrolyte refreshment and achieving a faster electrode feed rate and consequently decreasing the machining gap. Simulations of the electric field indicated that the current density was localized for the rotary helical electrode. Experiments verified that the rotary helical electrode decreased the machining gap from 94 to 19 μm compared with a cylindrical electrode of the same diameter. In addition, the effects of the process parameters on the interelectrode gap width were experimentally investigated. Finally, using optimal parameters, two precision microstructures with clean-cut edges were fabricated.

Fabrication of Taper Free Micro-Holes Utilizing a Combined Rotating Helical Electrode and Short Voltage Pulse by ECM

“…The principle and equivalent circuit of ECD with the ultra-short voltage pulse is shown in Figure 2 [29]. In Figure 2a, the cylindrical electrode feeds down at the rate of ν, the machining gap is Δb, the initial side gap is x0, and the side gap at the position of h from the bottom of the electrode is x.…”

Numerical modelling of ECMM of micro-dimples considering the effect of 3-phase electrolyte

“…A single electrode-based electrochemical micromachining is being widely used for hole drilling, 21 milling, 22, 23 micro-tools fabrication, 24 parting and structuring. 25 Single tool-based micro-texturing methodology opts from the earlier research of Patel et al 26, 27 where predesigned micro-tool is employed with zero feed at the minimum inter-electrode gap (IEG) which leads to the formation of bell-shaped micro-dimples.…”