Karmiris-Obratański Panagiotis, Papazoglou Emmanouil L, Leszczyńska-Madej Beata, Zagórski Krzysztof, Markopoulos Angelos P
Laboratory of Manufacturing Technology, School of Mechanical Engineering, National Technical University of Athens, 15780 Athens, Greece.
Department of Manufacturing Systems, Faculty of Mechanical Engineering and Robotics, AGH University of Science and Technology, 30-059 Cracow, Poland.
Materials (Basel). 2021 Jan 8;14(2):303. doi: 10.3390/ma14020303.
Electrical Discharge Machining (EDM) consists of a non-conventional machining process, which is widely used in modern industry, and especially in machining hard-to-cut materials. By employing EDM, complex shapes and geometries can be produced, with high dimensional accuracy. Titanium alloys, due to their unique inherent properties, are extensively utilized in high end applications. Nevertheless, they suffer from poor machinability, and thus, EDM is commonly employed for their machining. The current study presents an experimental investigation regarding the process of Ti-6Al-4V ELI with high power EDM, using a graphite electrode. Control parameters were the pulse-on current (I) and time (T), while Machining performances were estimated in terms of Material Removal Rate (MRR), Tool Material Removal Rate (TMRR), and Tool Wear Ratio (TWR). The machined Surface Roughness was calculated according to the Ra and the Rt values, by following the ISO 25178-2 standards. Furthermore, the EDMed surfaces were observed under optical and SEM microscopy, while their cross sections were also studied in order the Average White Layer Thickness (AWLT) and the Heat Affected Zone (HAZ) to be measured. Finally, for the aforementioned indexes, Analysis Of Variance was performed, whilst for the MRR and TMRR, based on the Response Surface Method (RSM), semi-empirical correlations were presented. The scope of the current paper is, through a series of experiments and by employing statistical tools, to present how two main machining parameters, i.e., pulse-on current and time, affect major machining performance indexes and the surface roughness.
电火花加工（EDM）是一种非常规加工工艺，在现代工业中广泛应用，尤其适用于加工难切削材料。通过采用电火花加工，可以生产出具有高尺寸精度的复杂形状和几何结构。钛合金因其独特的固有特性，在高端应用中被广泛使用。然而，它们的可加工性较差，因此，电火花加工通常用于其加工。当前的研究提出了一项关于使用石墨电极对Ti-6Al-4V ELI进行高功率电火花加工过程的实验研究。控制参数为脉冲导通电流（I）和时间（T），而加工性能则根据材料去除率（MRR）、工具材料去除率（TMRR）和工具磨损率（TWR）进行评估。根据ISO 25178-2标准，通过Ra和Rt值计算加工表面粗糙度。此外，在光学显微镜和扫描电子显微镜下观察电火花加工后的表面，同时还研究了它们的横截面，以便测量平均白层厚度（AWLT）和热影响区（HAZ）。最后，对上述指标进行了方差分析，而对于MRR和TMRR，基于响应面法（RSM）提出了半经验相关性。本文的目的是通过一系列实验并使用统计工具，展示两个主要加工参数，即脉冲导通电流和时间，如何影响主要加工性能指标和表面粗糙度。
