Investigating the effect of mixed alkaline electrolyte (NaOH + KOH) on the improvement of machining efficiency in 2D electrochemical discharge machining (ECDM)
Investigating the effect of mixed alkaline electrolyte (NaOH + KOH) on the improvement of machining efficiency in 2D electrochemical discharge machining (ECDM)
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DOI：
10.1007/s00170-017-1210-4
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发表时间：
2018-03
期刊：
影响因子：
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通讯作者：
Nasim Sabahi;M. Razfar
中科院分区：
文献类型：
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作者：
Nasim Sabahi;M. Razfar
由于微通道在微电子机械系统(MEMS)、微流控器件和芯片实验室中起着至关重要的作用，因此需要很好地控制微通道的表面质量、材料去除率和几何精度。电解液性质是影响电火花加工精度和性能的主要因素之一。在这一贡献中，两种碱性电解液NaOH和KOH以相等的比例混合。观察到，在相同浓度下，使用15和25wt%的NaOH+NaOH混合电解液比单独使用KOH和NaOH具有更好的导电性。与氢氧化钾和氢氧化钠相比，它可以制造出侧壁更锋利的更深的微通道，同时其表面质量也得到了保护。此外，使用25wt%、30wt%和35wt%的混合电解液，由于比KOH粘度更高，通道的表面质量分别提高了35%、42%和36%。通过对不同电解液电流响应波形的分析，发现在有盐电解液存在的情况下，由于产生极低的能量和不稳定的电火花，会形成MRR和表面质量都较差的微通道。在实验的另一部分中，扫描电子显微镜(SEM)图像和能量色散X射线(EDX)分析表明，在不同电解液中使用的碳化钨刀具的磨损比在氢氧化钾和混合电解液中使用的刀具更严重。此外，在50V的外加电压下，刀具的腐蚀比35V时的刀具腐蚀更严重。
Since the microchannels have a vital role in microelectromechanical systems (MEMS), microfluidic and lab-on-a-chip devices, the surface quality, material removal rate (MRR), and geometrical accuracy of microchannels should be controlled well. The electrolyte nature is one of the dominant and important factors that affect the accuracy and performance of electrochemical discharge machining (ECDM). In this contribution, two alkaline electrolytes, NaOH and KOH, were mixed in equal proportion. It was observed that using NaOH + KOH mixed electrolyte at 15 and 25 wt% concentrations provides more electrical conductivity than KOH and NaOH separately at the same concentrations. It results in the fabrication of deeper microchannel with sharper sidewalls compared to KOH and NaOH, while its surface quality is preserved as well. Also, using 25, 30, and 35 wt% mixed electrolyte, due to higher viscosity compared to KOH, improved the surface quality of channels up to 35, 42, and 36%, respectively. Analyzing the waveform of the current response of various electrolytes showed that the microchannel with poor MRR and surface quality will be fabricated in the presence of salt electrolytes due to the generation of very low energy and unstable electrochemical sparks. In another part of the experiments, scanning electron microscopy (SEM) images and energy-dispersive X-ray (EDX) analysis of the tungsten carbide (WC) tool used in different electrolytes showed that the tools used in NaOH and NaNO3had more severe wear compared to KOH and mixed electrolyte. Also, at the applied voltages of 50 V, the tool erosion was more serious compared to tool erosion at 35 V.