Multi-response optimization of WEDM Process Parameters using the AHP and TOPSIS method

The work presents a multi response optimization approach to determine the optimal process parameters in wire electrical discharge machining process. Experiments have been conducted using six process parameters such as discharge current, pulse duration, pulse frequency, wire speed, wire tension and dielectric flow rate each at three levels for obtaining the responses like material removal rate, roughness value of the worked surface (a measure of surface finish), and kerf. Taguchi 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, a multi criteria decision making method, techniques for order preference by similarity to ideal solution (TOPSIS) is applied in the present study. In order to consider experimental uncertainty, the responses are expressed in linguistic terms rather than crisp values. The weight for each criterion (response) is obtained by analytical hierarchy process instead of using intuition and judgement of the decision maker. Key words— WEDM, Multi-response optimization, Analytic hierarchy process (AHP), TOPSIS