Optimization of process parameters of cryogenic treated D-3 in WEDM by Taguchi Approach

Cryogenic treated high carbon high chromium alloy cold tool steels (D-3) are used in production of high performance dies, punches, blanking and punching tools, extrusion tools, etc. cryogenic treatment is a process of keeping the specimen in cold environment to increase its wear resistance and relieving its residual stresses. Due to its high hardness Wire Electric Discharge Machine (WEDM) seems a good option for machine hard material. In this paper, the effects of various process parameters of WEDM as pulse width, time between two pulses, maximum feed rate, servo reference mean voltage, short pulse time and wire mechanical tension, have been experimented for optimizing surface roughness (sr) while machining cryogenic treated D-3 material. Experimental observations are based on Taguchi’s L-27 orthogonal array has been done. Signalto-Noise (S/N) ratio, Analysis of Variance (ANOVA) and various plots are used to find the optimum process parameter with a least surface roughness. The confirmation experiments has been done for validate the results calculated by using taguchi method.