A Utility Concept Approach for Multi-objective optimization of Taper Cutting Operation using WEDM

The present study highlights a multi response optimization approach to determine the optimal process parameters in wire electrical discharge machining process during taper cutting operation. Experiments have been conducted using six process parameters such as part thickness, taper angle, pulse duration, discharge current, wire speed and wire tension each at three levels for obtaining the responses like angular error, surface roughness, and cutting speed. Taguchi's L27 orthogonal array is used to gather information regarding the process with less number of experimental runs. Traditional Taguchi approach is insufficient to solve a multi response optimization problem. In order to overcome this limitation, utility theory has been implemented, to convert multi-responses into single equivalent response called overall utility index. The weight for each criterion (response) is obtained by analytical hierarchy process (AHP) instead of using intuition and judgement of the decision maker. ANOVA analysis is also carried out to find out the significant effect of the process parameters during taper cutting in WEDM process. Finally confirmation test has been carried out to verify the result.