Application of integrated robust designation methodology in multi-objective optimization

Abstract

This paper demonstrates the optimizing process of multiple quality characteristics for Wire Electrical Discharge Machining (WEDM) of Fe-Al alloy parts via the Taguchi method-based Gray analysis. The modified algorithm adopted here successfully detrains the optimum settings of machine parameters and combines multiple quality characteristics into one integrated numerical value called the Gray relational grade. The essential machining parameters are identified as (1) servo voltage, (2) pulse-on time, (3) pulse-off time, (4) wire tension, (5) wire feed rate, and (6) no load voltage of the primary WEDM. Multiple quality characteristics required include: (1) high material removal rate, (2) small groove width, and (3) low surface roughness following WEDM. This work machines Fe-Al alloy parts under controlled machine parameter settings, and measures the above quality characteristics. The optimized machine parameter settings clearly improve quality characteristics of the machined workpiece compared to quality levels achieved for initial machine parameter settings. Material removal rate changes from 1.63 to 4.26 mm2/min; groove width decreases from 0.30 to 0.29 mm, and surface roughness on the workpiece reduces from 1.26 to1.21 µmRa.