||Electrochemical micro-machining (EMM) is one of the non-traditional manufacturing processes, shaping workpieces by electrolysis. The advantages include high processing speed, independent of metal properties, no surface residual stress, and smooth workpiece surface with enormous potentialities and highly added values. However, normal electrochemical micro-machining will afford higher expense because of the demand of the end product. The design expense of the electrode tool can be saved if using through-mask electrochemical machining (TMEMM). The purpose of using TMEMM is that the electrode tool won’t be affected by the end product shape. Without changing the electrode tool, TMEMM can fulfill end product, with any shape by only changing the shape of the electric insulated mask.|
In this study, copper is selected as the electrode tool, and a SUS 304 thin plate (0.1 mm) is taken as workpiece. Masks are made by using the screen printing process. The object of this research was to observe the effects of the electrolyte flow direction on through holes shape, and Taguchi Statistical Method is used to analyze the influences of parameters (e.g.: electrolyte concentration, applied voltage, diameter of the mask hole, and the thickness of the mask) on the undercut of single hole and uniformity of array holes, and estimate the best combination of parameters.
According to the results of the experiments, end product (drilled holes) is closer to a circle by using the forward flow mode. On the other hand, if we using the lateral flow mode, the shape of the end product will be more close to an oval profile. Therefore the forward flow mode is selected as the basis for the flowing experiments.
Furthermore, by the analysis of variance (ANOVA), it is found that the highest impact factors on the undercut of single hole and uniformity of array holes are the diameter of the mask hole and the thickness of the mask. And the best parameter combination is simultaneously acquired from the research. The best parameter combination for a small the undercut of single hole is A2B1C1D1, and the corresponding of undercut is 72 μm. The best parameter combination for the most uniformity of array holes is A2B3C1D3, and the corresponding averaged deviation is 7 μm.
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