Development of peeling tools with sub-50 μm cores by zinc electroplating and their application to micro-EDM

We previously proposed the concept of a peeling tool to overcome difficulties in handling thin electrodes during micro-electrical discharge machining. Here, we have further developed zinc-clad tools with tungsten cores as thin as 10 μm. The addition of dextrin to the zinc electroplating solution dramatically improved tool accuracy. The zinc layer of the tool tip can be selectively removed by a single discharge in air to expose the core without damage, even for sub-50 μm cores. Microholes were then drilled using the exposed core. The possibility of simultaneous microhole drilling and clad removal was verified using a 10-μm core tool.