This paper introduces an experimental investigation of micro hole drilling on two different categories of material such as silicon and german silver using micro electrical discharge machining (μEDM) process. The conductivities of the two materials are of different levels; silicon being a semiconductor has relatively much lower electrical conductivity as compared to german silver which is an alloy of copper, nickel and zinc. The tool electrode used is tungsten rod of 518 μm diameter. Responses like material removal rate (MRR), taper angle (TA), circularity error (CE) and overcut (OC) have been calculated and their variation with respect to the process parameters such as capacitance and voltage are evaluated. In both the materials, the values of all the responses increases with an increase in both voltage and capacitance. German silver is observed to have a higher MRR and OC than that of silicon while silicon has a higher TA for the same values of process parameters. The CE of silicon is higher at lower capacitance while it is higher for german silver at higher capacitance. From the analysis of variance (ANOVA), it is observed that both the voltage and capacitance played a significant role in all the responses. An optimum condition of micro hole drilling of both the materials is achieved by formulating overall evaluation criteria (OEC), which combines all the response parameters into a single index. In most of the cases, OEC of german silver is found to be higher than silicon, thus justifying the superior machinability performance of german silver. From the ANOVA of OEC, the role of capacitance is found to be more significant as compared to the voltage.

本文介绍了使用微放电加工（μEDM）工艺在两种不同类别的材料（例如硅和德国银）上进行微孔钻孔的实验研究。两种材料的电导率不同。与作为铜，镍和锌的合金的德国银相比，作为半导体的硅具有相对低得多的电导率。所使用的工具电极是直径518μm的钨棒。已计算出诸如材料去除率（MRR），锥角（TA），圆度误差（CE）和过切（OC）之类的响应，并评估它们相对于诸如电容和电压之类的工艺参数的变化。在这两种材料中，所有响应的值都随电压和电容的增加而增加。观察到德国银比硅具有更高的MRR和OC，而对于相同的工艺参数值，硅具有更高的TA。硅的CE在较低电容下较高，而德国银在较高电容下较高。从方差分析（ANOVA）中可以看出，电压和电容在所有响应中均起着重要作用。通过制定总体评估标准（OEC），将两种材料的所有响应参数合并为一个指标，可以实现两种材料的微孔钻孔的最佳条件。在大多数情况下，发现德国白银的OEC高于硅，因此证明了德国白银的优异机加工性能。根据OEC的ANOVA，发现电容的作用比电压更重要。