针对难加工金属材料表面阵列非贯穿型微沟槽的高效高质量加工难题, 提出一种场域离散脉冲电解加工方法, 所加工沟槽具有表面质量好、尺寸微小、槽数多、沟槽前后非贯穿的特点。使用绝缘栅栏隔板作为活动掩模板对各微沟槽加工区进行离散, 同时遮蔽非加工区, 从而实现流场隔离和非加工区电场屏蔽等效果, 有效提高沟槽的加工稳定性、精度和一致性。通过设计专用夹具, 对影响加工精度的关键因素进行了单因素工艺实验研究, 并利用Comsol Multiphysics软件对电解加工的流场和电场进行了仿真分析。仿真和试验结果显示: 场域离散加工方法的流场和电场都比传统的掩膜电解加工、电解转印加工好。成功地在1 min内加工出9条宽538.76 μm, 深25.78 μm, 过切量为19.38 μm的阵列微沟槽, 证实了该方法的有效性。采用短加工时间、低脉冲电压幅值、高脉冲频率、小脉冲占空比等工艺参数, 有利于提高沟槽的加工精度。通过场域离散电解加工技术, 可以实现对非贯穿型微沟槽的高效率、高质量、低成本加工。

A method of pulse electrochemical machining in discrete fields and domains was introduced to solve the problems in microchannel arrays machining on difficult-to-cut metal surface. This method has the characteristics of processing microchannels with high surface quality and a non-penetrating structure. The machining zone of each channel was separated by the specially designed fence-like template made of nonconductive material, and hence the electrolyte flow field and electric field are confined and improved, because of which a higher process stability and good machining accuracy and consistency can be achieved. Both simulation analysis and experiments verified the effectiveness of the method. The distributions of flow field and electrical field of this method are better than those of the through-mask Electrochemical Machining (ECM) method and electrochemical pattern transfer method. Nine channels with a 538.76 μm width, 25.78 μm depth, and an overcut of 19.38 μm are obtained within 1 min. Single-factor experiments were conducted and the results show that good process performance can be obtained with a short machining time, low voltage amplitude, low duty cycle, and high pulse frequency. Thus, the presented method of pulse EMC in discrete fields and domains is suitable for mass production of non-penetrating microstructures with the advantages of high efficiency, high quality, and low cost.