Abstract Bipolar plate is an important component in proton exchange membrane fuel cell. The machining of micro-channel array is a key process for the fabrication of metallic bipolar plate. This paper proposed a novel approach named electrochemical direct-writing machining for generating micro-channel array on thin metallic plate at one time, showing a high machining efficiency. In this method, an insulated mask with a row of micro through-holes was integrated to a metallic nozzle, the electrolyte ejected from the nozzle reached to the workpiece through micro through-holes, and then the micro-channel array could be generated from dots to lines by controlling the movement of workpiece. In the machining process, the non-processing zones were covered by the insulated mask, which avoided the stray corrosion. By analyzing the results of simulation and experiment, it was found that due to the accumulation of electrolytic product in the ending point, the profile of this point was different from that of the starting point. The parameters with the voltage of 20 V and pulse duty cycle of 20% were useful for preparing micro channel with good profile and low dimensional difference. And compared with other pulse frequencies, the pulse frequency of 2 kHz could obtain a deeper micro channel. With other parameters unaltered, the dimension of micro channel was decreased with the increasing moving speed of workpiece. At last, with the optimized parameters (voltage = 20 V, pulse duty cycle = 20%, pulse frequency = 2 kHz, and moving speed = 20 μm·s−1), ten micro channels with the length of 60 mm were generated at one time on a metallic plate with the thickness of 0.5 mm. The width was 302 ± 3.53 μm (Mean ± SD) and the depth was 95.9 ± 1.34 μm, showing a satisfied dimensional consistency.

中文翻译：

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微通道阵列的电化学直写加工

摘要 双极板是质子交换膜燃料电池的重要组成部分。微通道阵列的加工是金属双极板制造的关键工艺。本文提出了一种称为电化学直写加工的新方法，用于在薄金属板上一次性生成微通道阵列，具有较高的加工效率。该方法将带有一排微通孔的绝缘掩模集成到金属喷嘴上，从喷嘴喷出的电解液通过微通孔到达工件，然后由点产生微通道阵列通过控制工件的运动到线。在加工过程中，非加工区被绝缘罩覆盖，避免了杂散腐蚀。通过对模拟和实验结果的分析，发现由于电解产物在终点的堆积，该点的剖面与起点的剖面不同。电压为20 V、脉冲占空比为20%的参数有助于制备具有良好轮廓和低尺寸差异的微通道。并且与其他脉冲频率相比，2kHz的脉冲频率可以获得更深的微通道。在其他参数不变的情况下，微通道尺寸随着工件移动速度的增加而减小。最后，以优化的参数（电压=20 V，脉冲占空比=20%，脉冲频率=2 kHz，移动速度=20 μm·s−1）在一次在厚度为 0 的金属板上。5 毫米。宽度为302±3.53μm（平均值±SD），深度为95.9±1.34μm，尺寸一致性令人满意。