Investigations on Tool Wear Rate of AISI D2 Die Steel in EDM using Taguchi Methods

Abstract

EDM has become an important and cost-effective method of machining extremely tough and brittle electrically conductive materials. It is widely used in the process of making moulds and dies and sections of complex geometry and intricate shapes. The workpiece material selected in this study is AISI D2 Die Steel. The input parameters are voltage, current, pulse on time and pulse off time. L₉ orthogonal array was selected as per the Taguchi method. The data have been analyzed using Minitab15 Software. The effect of above mentioned parameters upon machining performance characteristics such as Tool Wear Rate (TWR) are studied and investigated on the machine model C-3822 with PSR-20 Electric Discharge Machine.  The copper alloy was used as tool material.The results obtained showed that the optimum condition for tool wear rate (TWR) is A3, B2, C2, D3 i.e. Ton (40µs),Toff (8 µs), Ip (8 amp) and Vg (60V). The order of process parameters influencing the tool wear rate is Toff 12>"> Ip 12>"> Ton 12>"> Vg. Hence, pulse off parameter has more contribution to tool wear rate whereas gap voltage has the least contribution. As per the optimal level of parameters, the optimum value of TWR is 0.117 mm³/min. These results were validated by conducting confirmation experiments and found satisfactory.

Keywords: EDM,TWR, MRR, ANOVA, Taguchi method, AISI D2 Die steel, copper electrode