The present study investigates the influence of adding multi-wall carbon nanotube (MWCNT) into the dielectric fluid of electric discharge machining (EDM) in terms of material removal rate (MRR), surface roughness (SR) and surface topology of EN-31 die steel using Cu electrode. A customized rotary electrode set-up has been developed to compare the performance improvement of powder mixed rotary electrical discharge machining (PMREDM) as compared to powder mixed electrical discharge machining (PMEDM) and conventional EDM. The present study attempts to investigate the optimization of process parameters of MWCNT mixed rotary EDM of EN-31 die steel using response surface methodology (RSM) and genetic algorithm (GA) in terms of MRR and SR. The optimization results show that MWCNT mixed rotary EDM shows highest value of MRR (9.72 mm³/min) and lowest value of SR (R_a = 2.03 µm), which are approximately 46.17% higher and 45.43% lower than conventional EDM values respectively. Further, various combinations of optimal values of MRR and SR and their corresponding input parameters setting have been shown in pareto table created by multi-objective optimization GA technique available in MATLAB. Finally, field emission scanning electron microscope (FESEM) analysis of MWCNT mixed rotary EDM and EDM surfaces is carried out which revealsthat MWCNT mixed rotary EDM shows better surface topography as compared to EDM process.

中文翻译：

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MWCNT混合旋转电火花加工提高EN-31模具钢的加工性能

本研究从材料去除率（MRR），表面粗糙度（SR）和EN-31模具的表面拓扑方面研究了在放电加工（EDM）的介电液中添加多壁碳纳米管（MWCNT）的影响钢使用铜电极。已经开发了定制的旋转电极装置，以比较粉末混合旋转放电加工（PMREDM）与粉末混合放电加工（PMEDM）和常规EDM相比的性能改进。本研究试图利用响应面方法（RSM）和遗传算法（GA）从MRR和SR角度研究EN-31模具钢的MWCNT混合旋转电火花加工工艺参数的优化。优化结果表明，MWCNT混合旋转电火花加工的MRR最高（9.72 mm³ / min）和SR的最低值（R _a = 2.03 µm），分别比常规EDM值高约46.17％和低45.43％。此外，在通过MATLAB中可用的多目标优化GA技术创建的pareto表中，已显示MRR和SR的最佳值的各种组合及其对应的输入参数设置。最后，对MWCNT混合旋转EDM和EDM表面进行场发射扫描电子显微镜（FESEM）分析，发现MWCNT混合旋转EDM的表面形貌比EDM工艺更好。