Through-mask electrochemical micromachining (TMEMM) is a promising method to prepare micro dimples on the surface of metallic parts. However, the workpiece is machined one by one in traditional TMEMM. This paper introduced bidirectional pulse to TMEMM to improve the machining efficiency. Two masked workpieces were placed face to face, and connected to the ends of the bidirectional pulse power supply. Along with the change of the pulse direction, the polarities of the two workpieces were interchanged periodically, and micro dimples could be prepared on both workpieces at one time. The simulation and experiment results indicated that with bidirectional pulse mode, micro dimples with same the profile can be prepared on two workpieces at one time, and the dimension of micro dimple was smaller than that with unidirectional pulse mode. In bidirectional pulse current, the pulse frequency and pulse duty cycle played an important role on the preparation of micro dimple. With high pulse frequency and low pulse duty cycle, it is useful to reduce the undercut of micro dimple and improve the machining localization. With the pulse duty cycle of 20% and pulse frequency of 10 kHz, micro dimples with etch factor (EF) of 3 were well prepared on both workpieces surface.

中文翻译：

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微凹坑双向脉冲电化学微加工研究

通过掩模电化学微加工（TMEMM）是在金属零件表面制备微凹坑的一种很有前途的方法。但是，传统的TMEMM中，工件是一个一个加工的。本文将双向脉冲引入 TMEMM 以提高加工效率。两个蒙面工件面对面放置，并连接到双向脉冲电源的末端。随着脉冲方向的变化，两个工件的极性周期性地互换，可以同时在两个工件上制备微凹坑。仿真和实验结果表明，双向脉冲模式可以同时在两个工件上制备轮廓相同的微凹坑，且微凹坑的尺寸比单向脉冲模式小。在双向脉冲电流中，脉冲频率和脉冲占空比对微凹坑的制备起到了重要作用。脉冲频率高，脉冲占空比低，有利于减少微凹坑的咬边，提高加工定位。在 20% 的脉冲占空比和 10 kHz 的脉冲频率下，具有蚀刻因子的微凹坑 (EF ) 3 在两个工件表面上都做好了准备。