A STUDY ON THE MACHINING-PARAMETERS OPTIMIZATION OF WIRE ELECTRICAL-DISCHARGE MACHINING

A suitable selection of machining parameters for the wire electrical d ischarge machining (WEDM) process relies heavily on the operators' tec hnologies and experience because of their numerous and diverse range. Machining-parameters tables provided by the machine-tool builder can n ot meet the operators' requirements, since for an arbitrary desired ro ughness of the machining surface, they do not provide the optimal mach ining conditions. An approach to determine parameters setting is propo sed. Based on the Taguchi quality design method and the analysis of va riance, the significant factors affecting the machining performance su ch as metal removal rate, gap width, surface roughness, sparking frequ ency, average gap voltage and normal ratio (ratio of normal sparks to total sparks) are determined. By means of regression analysis, mathema tical models relating the machining performance and various machining parameters are established. Based on the mathematical models developed , an objective function under the multi-constraint conditions is formu lated. The optimization problem is solved by the feasible direction me thod, and the optimal machining parameters are obtained. Experimental results demonstrate that the machining models are appropriate and the derived machining parameters satisfy the real requirements in practice . (C) 1997 Elsevier Science S.A.