Ns-pulsewidth pulsed power supply by regulating electrical parameters for AFM nano EDM of nm-removal-resolution
Ns-pulsewidth pulsed power supply by regulating electrical parameters for AFM nano EDM of nm-removal-resolution
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DOI：
10.1088/1361-6528/ac0029
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发表时间：
2021-05
期刊：
影响因子：
3.5
通讯作者：
Ran Quan;H. Tong;Yong Li
中科院分区：
文献类型：
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作者：
Ran Quan;H. Tong;Yong Li
纳米电火花加工作为一种处于探索研究阶段的前沿加工方法，在金属及合金材料加工中实现纳米级的加工分辨率具有重要的应用前景。纳米电火花加工中的脉冲电源有望将单次脉冲能量限制在nJ量级，以提高单次脉冲放电的加工分辨率，甚至达到纳米级。减小脉冲电源的脉宽是一个发展方向。传统的脉冲电源很难输出纳秒级的单脉冲和连续脉冲，导致单脉冲能量过大，通常达到μJ量级。本研究设计了一种新型的脉宽和峰值电压可控的纳秒脉冲电源。其关键新奇在于采用了一种工作在超快雪崩导通状态下的双三极管级联电路，并利用pF电容实现了脉宽和脉冲能量的精确调节。性能测试验证了可以输出5ns脉宽的单脉冲或高达9MHz的连续脉冲。在此基础上，利用原子力显微镜（AFM）系统，在纳米级放电间隙和纳米尖端电极条件下，进行了单脉冲放电纳米电火花加工实验。实验结果表明：在10 ns的脉冲宽度下，单脉冲能量可达1.75 nJ，放电坑直径仅为182 nm，形状规则，几乎不重铸。这些结果验证了基于AFM针尖的纳米电火花加工纳米结构的可能性。
Nano electro discharge machining (nano EDM), as a frontier processing method in the research stage of exploration, has an important application prospect in the machining of metal and alloy materials for achieving nanoscale removal resolution. A pulsed power supply used in nano EDM is expected to limit a single pulse energy to nJ order of magnitude for improving the removal resolution of single pulsed discharge even to nanoscale. One developing direction is to decrease pulsewidth of the pulsed power supply. Conventional pulsed power supplies hardly output a single pulse and continuous pulses with nanosecond (ns) pulsewidth, resulting in too large single pulsed energy of μJ order of magnitude usually. In this research, a novel pulsed power supply is designed for realizing the ns-pulsewidth with controllable pulsewidth and peak voltage. The key novelty lies in a cascaded circuit with two triodes working in the state of ultra-fast avalanche conduction, where pF capacitors are applied to adjust the pulsewidth and pulsed energy precisely. Performance tests verified that a single pulse of 5 ns pulsewidth or continuous pulses up to 9 MHz can be outputted. Furthermore, nano EDM experiments of single pulsed discharge are carried out under the conditions of nanometer (nm) discharge gap and nm-tip tool electrode based on an atomic force microscope (AFM) system. The special results are achieved: a single pulsed energy can reach down to 1.75 nJ by outputting a pulsewidth of 10 ns, and a nano-EDM crater is only about 182 nm in diameter with regular shape and little recasting. Those results verify the possibility of AFM-tip-based nano EDM for machining nanostructures.