针对加工某微小装置的局部微尖槽形状精度难以保证的问题, 提出一种多工位尖角电极电火花成形的方法。以304不锈钢为工件材料, 选择纯铜和铜钨合金(W75%)作为电极材料并进行试验比较。为减小电极损耗和重复定位误差对加工精度的影响, 采用慢走丝电火花线切割加工多工位尖角电极, 然后利用多工位尖角电极电火花成形夹角为16°、深度为0.36 mm的微尖槽。结果表明: 采用较低进给速度, 恒速多次线切割的方法能制作出质量较好的多工位尖角电极; 尖槽成形精度随着工位数的增加而提高, 且相同工位数时由于铜钨合金电极的低损耗性能使尖槽成形精度更好。最终采用6工位的铜钨合金电极成形微尖槽角度为16.3°, 相对误差1.9%; 深度为0.356 mm, 相对误差1.1%, 形状精度也较好。该方法可以满足某微小装置中微尖槽部分的加工精度和使用要求。

To solve the difficulty of ensuring the shape accuracy of micro grooves in a micro device, a new method of using multi-station shape-angle electrodes through Electrical Discharge Machining (EDM) was proposed. A total of 304 stainless steel samples were used as workpiece materials, and pure copper and copper-tungsten alloy (W75%) were selected and compared as electrode materials. To reduce the influence of electrode wear and installation error, multi-station shape-angle electrodes were machined by low-speed Wire-cut EDM (WEDM), and then a 16° and 0.36-mm-depth groove was formed by EDM. Results show that a multi-station shape-angle electrode having enhanced surface quality can be fabricated using a lower feed rate, a constant speed, and multiple cutting through WEDM. The forming accuracy of the grooves was improved with the increase in the number of stations, and the forming accuracy of the copper-tungsten alloy was improved as a result of its low loss at the same station number. Therefore, a six-station copper-tungsten electrode was used to machine the workpiece with a sharp angle of 16.3° (relative error of 1.9%), a 0.356-mm depth (relative error of 1.1%), and improved form accuracy. This method can meet the processing accuracy and application requirements of sharp grooves in a micro device.