Statistical analysis on electrode wear in EDM of tool steel DIN 1.2714 used in forging dies

Electrical discharge machining (EDM) is a widespread process which works very effectively in machining of difficult-to-cut materials and alloys in die and aerospace industries with high dimensional accuracies. However, this capability could be deteriorated due to electrode wear leading to decrease of process productivity. In this study, the effect of machining parameters of EDM process including on-time, current, voltage, the engaging time between workpiece and electrode, and pre-EDM roughing on electrode wear were experimentally investigated. Main effects of factors and interactions were considered in this paper and regression equation was derived. A L50 (21 × 511) Taguchiʹs standard orthogonal array was employed as experimental design. Copper was used as electrode to machine the hot work tool steel 1.2714, which is widely used to make forging dies and mandrels.