Modeling of radial gap formed by material dissolution in simultaneous micro-EDM and micro-ECM drilling using deionized water
Modeling of radial gap formed by material dissolution in simultaneous micro-EDM and micro-ECM drilling using deionized water
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DOI：
10.1016/j.ijmachtools.2012.12.001
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发表时间：
2013-03
影响因子：
14
通讯作者：
M. D. Nguyen;Mustafizur Rahman;Y. Wong
中科院分区：
文献类型：
--
作者：
M. D. Nguyen;Mustafizur Rahman;Y. Wong
为了提高微细孔的表面质量，将微细电火花加工和微细电解加工结合起来，采用低电阻率去离子水作为双特性流体，形成了一种独特的微细电火花-微细电解复合加工工艺。电火花产生的变质层在电化学反应的作用下进一步从加工表面上溶解。为了保持微孔的尺寸精度，施加短电压脉冲以定位材料溶解区，因此进一步去除的材料层的厚度在决定微孔的最终尺寸中是首要的。本研究提出以电化学反应进一步溶解的材料层厚度预测微细电火花加工与微细电解加工同时进行时的径向间隙距离的模型。结合双电层理论，Butler-Volmer方程和电解的法拉第定律的分析方法被用来模拟不同的脉冲参数的径向间隙距离。仿真数据与实验结果进行了验证。据观察，所施加的脉冲参数直接影响所获得的微孔的最终尺寸。短电压脉冲定位材料溶解区的有效性被发现是根据双层充电特性。当脉冲宽度过短时，材料的溶解可以忽略不计，SEDCM对改善微孔内表面没有作用。
For enhancing the surface finish of micro-holes, micro-EDM and micro-ECM have been combined in a unique hybrid machining process by using low-resistivity deionized water as bi-characteristic fluid. The affected material layer generated by electric sparks is further dissolved from machined surface owing to the effect of electrochemical reaction. To maintain the dimensional accuracy of micro-holes, short voltage pulses are applied to localize the material dissolution zone and thus the thickness of further removed material layer is of prime importance in deciding the final dimension of micro-holes. This study presents the modeling of radial gap distance in simultaneous micro-EDM and micro-ECM drilling by predicting the thickness of material layer further dissolved by electrochemical reaction. The analytical approach incorporating the double-layer theory, the Butler–Volmer equation and the Faraday's law of electrolysis is used to simulate the radial gap distance for different pulse parameters. The simulation data is then verified with the experimental results. It is observed that the applied pulse parameters directly affect the final dimension of obtained micro-holes. The effectiveness of short voltage pulses in localizing the material dissolution zone is found to be in accordance with the double-layer charging characteristic. When the pulse duration is too short, the material dissolution is negligible and SEDCM has no effect on improving the inner surface of micro-hole.