Elimination of 3D micro-electrode’s step effect and applying it in micro-EDM

3D micro-electrode is fitted out by multilayer 2D micro-structures, so the steps inevitably occur in the 3D micro-electrode. When the 3D micro-electrode is used in micro-EDM, steps are replicated onto the surface of the 3D micro-structure, which have an adverse impact on the shape precision of the 3D micro-structure. Focus on this problem, this paper proposed to eliminate the steps of the 3D micro-electrode based on skin effect and point discharge. Then, the paper detailedly researched the impact of machining voltage, machining depth, and processing numbers on the elimination of 3D micro-electrode’s step effect and its micro-EDM results. In order to verify the feasibility of this method, the paper designed a 3D micro-cavity structure which has slopes in the X and Y directions with slope angle of 45°. Finally, under workpiece of 304# stainless steel, pulse width of 800 ns, pulse interval of 4200 ns, machining voltage of 110 V, and machining depth of 650 μm (250 μm larger than the design depth), the step effect of the 3D micro-electrode was effectively eliminated and its micro-EDM result has a dimension error within 7 μm and slope error within 3°.