Micro-electrode wear and compensation to ensure the dimensional consistency accuracy of micro-hole array in micro-EDM drilling
Micro-electrode wear and compensation to ensure the dimensional consistency accuracy of micro-hole array in micro-EDM drilling
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DOI：
10.1007/s00170-020-05811-y
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发表时间：
2020-11-01
影响因子：
3.4
通讯作者：
Shaojie, Hou
中科院分区：
文献类型：
--
作者：
Huan, Liu;Jicheng, Bai;Shaojie, Hou
利用微细电火花加工技术加工出的微细孔阵列在喷墨喷嘴、喷油嘴、喷油嘴等工业领域得到了广泛的应用，但微细孔阵列的尺寸一致性精度难以保证。为满足微细孔阵列加工的尺寸一致性精度要求，研究了微细电极磨损的特点及补偿策略。研究了脉冲发生器参数对微电极磨损的影响，通过优化脉冲发生器参数降低了微电极磨损。研究了微电极的几何演化规律，并根据微电极的磨损特性建立了微电极磨损模型。通过分析微电极的磨损特性，在加工过程中采用单孔定量补偿策略。同时，提出了分组检测变量补偿策略，周期性调整微电极轴向位置，消除累积补偿误差。在50 μ m厚的不锈钢上加工出平均直径为45.28 μ m的256个（16 × 16）微孔阵列。微孔阵列的尺寸一致性精度得到保证，显示出0.15 μ m的标准偏差。此外，加工了64个（8 × 8）微孔阵列和25个（5 × 5）微孔阵列，平均直径小于20 μ m，以探索更小尺寸的微孔阵列加工性能，尺寸一致性精度分别为0.25和0.4 μ m的标准偏差。
The micro-hole array machined by microelectrical discharge machining (micro-EDM) has been widely used in industrial fields, such as inkjet nozzle, oil nozzle, spinneret, and so on. However, it is difficult to guarantee the dimensional consistency accuracy of micro-hole array. In the present study, the characteristic and compensation strategy of microelectrode wear were explored to meet the requirements of dimensional consistency accuracy of micro-hole array machining. The effect of pulse generator parameters on microelectrode wear was studied, and the microelectrode wear was reduced by optimizing pulse generator parameters. The geometry evolution rule of microelectrode was investigated, and the microelectrode wear model was established based on the wear characteristic of microelectrode. By analyzing the wear characteristic of microelectrode, single-hole quantitative compensation strategy was adopted during the machining process. Meanwhile, grouping detection variable compensation strategy was proposed to adjust axial position of microelectrode periodically in order to eliminate the cumulative compensation errors. The array of 256 (16 x 16) micro-holes with an average diameter of 45.28 mu m was machined on a 50-mu m-thick stainless steel. The dimensional consistency accuracy of micro-hole array was assured by showing a standard deviation of 0.15 mu m. In addition, the array of 64 (8 x 8) micro-holes and the array of 25 (5 x 5) micro-holes with an average diameter of less than 20 mu m were machined to explore the performance of micro-hole array machining with smaller size, and the dimensional consistency accuracy was shown by the standard deviation of 0.25 and 0.4 mu m, respectively.