Achieving good material removal rate (MRR) along with better surface roughness is a challenging task for the present machining industry. The present study proposes Taguchi-method-based multiple-response grey relational analysis to find the optimal combination of machining parameters for maximum MRR and minimum surface roughness (R _a) in wire electro-discharge machining (WEDM) of EN 47 spring steel. The effects of four process parameters – namely, pulse-on time, pulse-off time, gap voltage and wire feed – on the machining characteristics (MRR and R _a) were studied with the help of an L₂₇ orthogonal array, which was used to study the main effect as well as the interaction effect of the parameters. The grey relational grade was the performance index which is used to study the behaviour of machining parameters in WEDM of EN 47 spring steel with respect to the MRR and R _a. Signal-to-noise ratio analysis and analysis of variance are done by taking the grey relational grade as the combined response. It is observed that the pulse-on time was the most significant process parameter, whereas the pulse-off time had a moderate effect on the MRR and R _a. Moreover, significant interactions were found in all three cases in controlling MRR and R _a. The surface morphology and composition were studied with the help of scanning electron microscopy and chemical analysis.

中文翻译：

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工艺参数对WEDM加工EN 47弹簧钢的影响

实现良好的材料去除率（MRR）以及更好的表面粗糙度是当前机械加工行业的一项艰巨任务。本研究提出了基于Taguchi方法的多响应灰色关联分析，以找到EN 47弹簧钢的线材放电加工（WEDM）中最大MRR和最小表面粗糙度（R _a）的加工参数的最佳组合。借助L ₂₇研究了四个工艺参数（脉冲接通时间，脉冲断开时间，间隙电压和送丝）对加工特性（MRR和R _a）的影响。正交阵列，用于研究主效应以及参数的相互作用效应。灰色关联等级是性能指标，用于研究EN 47弹簧钢的WEDM中加工参数相对于MRR和R _a的行为。以灰色关联度作为组合响应，进行信噪比分析和方差分析。可以看出，脉冲接通时间是最重要的过程参数，而脉冲断开时间对MRR和R _a的影响中等。此外，在控制MRR和R _a的所有三种情况下均发现了显着的相互作用。。借助扫描电子显微镜和化学分析研究了表面形态和组成。