纳秒脉冲微细电化学加工的理论及试验

THEORETICAL AND EXPERIMENTAL RESEARCH INTO ELECTROCHEMICAL MICRO-MACHINING USING NANOSECOND PULSES

根据电化学反应原理,探讨纳秒脉冲电化学加工的特点及其实现微细加工的机理。建立纳秒脉冲微细电化学加工的理论模型,并分析电解液浓度、加工间隙、脉冲参数和加工电压等因素对微细电解加工的影响作用。构建微细电化学加工系统,包括微细加工机床、纳秒脉冲电源、电解液循环系统、运动控制部分和加工检测部分。试验研究了超短脉冲的电压幅值和脉冲宽度对侧面加工间隙的影响,结果表明减小脉冲宽度和降低加工电压可以提高微细电解加工的精度。在自制的微细电化学机床上,实现工具电极和工件微结构的连续加工。将加工间隙控制在5μm以内,加工出中间有20μm×30μm×30μm棱台的微型腔和30μm槽宽的十字形孔,分析加工起始点对成形精度的影响,并提出解决方法。试验证明纳秒脉冲微细电解加工可以很好地满足微机电系统(Micro e1ectro-mechanical system,MEMS)微器件的加工要求。

Based on the principle of electrochemical reactions, the characteristic and mechanism of nanosecond pulses electrochemical micro-machining are investigated and the theoretical model of mi machining （ECM） is founded The affections of electrolyte concentration, electrodes gap and pulse parameters on the result of electrochemical micro-machining are discussed. The practical electrochemical machining system is developed. It consists of micro-machining equipment, nanosecond pulse power supply, electrolyte circulating system,movement control component and process monitoring component. The effects of pulse on-time and voltage on the side gap of electrodes are investigated with experiments. The result of experiments show that decreasing pulse duration and voltage can enhance the localization and improve electrochemical micromachining accuracy. On the self-developed equipment, tool electrode and workpiece are sequentially machining in electrochemical method. Inter-electrode gap is restrained less than 5 μm. A crisscross micro-groove with 30 μm width and the mic- ro-structure with size 20 μm×30 μm×30μm is produced. The influence of starting point upon forming precision is analyzed. The experimental results prove that miero-ECM can well meet the demand of micro machining.