Optimization of Micro-Wire EDM Operation Using Grey Taguchi Method

Abstract

Micro-wire EDM is an emerging technology in the field of Micro-machining to fabricate very complex micro products. Micro wire EDM is a very complex process involving the different process parameters. In the present investigation an optimization of micro wire EDM has been carried out using Grey Taguchi method. The parameters involved are voltage, capacitance, feed rate and wire speed. MRR and kerf width are taken as the response criteria. Experimental investigation has been carried out in multi-process Micro-EDM machine. Wire electrical discharge machining process is a highly complex, time varying & stochastic process. This is used in the fields of dies, molds; precision manufacturing and contour cutting etc. any complex shape can be generated with high grade of accuracy and surface finish using CNC WEDM. The output of the process is affected by large no of input variables. Hence a suitable selection of input variables for the wire electrical discharge machining (WEDM) process depends heavily on the operator’s technology & experience. WEDM is extensively used in machining of conductive materials when precision is of prime importance. Rough cutting operation in wire EDM is very challenging one because improvement of more than one performance measures viz. Metal removal rate (MRR), surface finish & cutting width (kerf) are of prime importance. This paper proposes optimal parameter setting. Using taguchi's parameter
design, significant machining parameters affecting the performance measures are identified as pulse peak current, pulse on time, and duty factor. The effect of each control factor on the performance measure is studied individually using the plots of signal to noise ratio. The study demonstrates that the WEDM process parameters can be adjusted so as to achieve better metal removal rate, surface finish, electrode wear rate.