Multi-response optimization of Wire-EDM process using principal component analysis

Abstract

Wire electrical discharge machining (WEDM) has been found to be an extremely potential electro-thermal process in the field of conductive material machining. This process employed for the parts demanding higher accuracy levels with varying hardness or complex shapes, which have sharp edges that are very difficult to be machined by main stream processes. WEDM is a complex machining process controlled by a large number of process parameters such as the pulse duration, discharge frequency and discharge current density. Any slight variations in the process parameters can affect the machining performance measures such as surface roughness and cutting ratio. Taguchi method is widely used for optimization of various processes. Using Taguchi method, the parametric settings can be optimized with respect to one performance characteristic (response) at a time, whereas wire electrical discharge machining (WEDM) processes require optimization of multiple performance characteristics. Researchers have attempted several approaches but determination of the optimal process settings that can optimize multiple performance measures (responses) of WEDM operations still remains an important issue. In this paper, weighted principal component (WPC) method is used to optimize the multiple responses of WEDM processes. The results show that the WPC method offers significantly better overall quality than the other approaches.