Improving accuracy and aspect ratio of tungsten micro-rods using CS-WEDG

For improving accuracy and aspect ratio of micro-rods, a wire electrical discharge grinding method based on controllable slit (CS-WEDG) was proposed. Wire electrode included angle β effectively improves material removal accuracy of micro-rods and makes removal resolution smaller than the feed resolution of motion axis. In addition, the CS-WEDG method has the advantage of being insensitive to the machine tool positioning accuracy. Through experiments, it is found that the wire electrode fluctuation amplitude has a positive correlation with the tension fluctuation rate. The adverse influence of wire electrode fluctuation can be avoided by keeping the wire electrode stationary during finishing. The micro-rod is affected by wire electrode wear (WEW) when fed along the rectangular wave path, resulting in an olive-shaped outline. By optimizing feed path, the inverted triangle feed strategy can compensate for wire electrode wear, which can control the diameter error of micro-rods within ± 1 μm. Through the optimization of feed parameters, the high aspect ratio micro-rod can be fabricated, which has a 48 ± 1 μm diameter with a 33.3 aspect ratio.