Effect of nichroloy coated electrode on machining performance of electrical discharge machining using Inconel 625

Abstract

Abstract EDM is an important method for machining of hard and difficult to machine materials by other traditional methods such as titanium alloy, tool steels, carbides, super alloys, heat resistant steels etc. It has applications in die making, mold making industries, automobile industries, aerospace etc. EDM machining can be used for machining of difficult geometry and intricate shape components. In present work, INCONEL 625 work material is used. This material has wide range of applications in seawater components, petrochemicals, aircraft ducting system, jet engine applications etc. Two tools are used one is copper and other is nichroloy coated copper tool. The experiment is conducted using Taguchi design. Input process parameters are pulse on time (Ton), duty cycle (dc), Peak current (Ip) and Gap voltage (Vg). Material removal rate (MRR) and surface roughness (SR) are response characteristics. Influence of input parameters over the responses are studied. Analysis of variance (ANOVA) is used to find the percentage contribution of input parameters. Grey relational analysis (GRA) is used which provides optimized result. It is observed that copper tool produces higher MRR and nichroloy coated tool produces fine surfaces. Optimal parameter setting is Ton\u202f=\u202f500\u202fµs, dc\u202f=\u202f9, Ip\u202f=\u202f25 amp and Vg\u202f=\u202f20\u202fV.