STUDY OF MATERIAL REMOVAL RATE OF DIFFERENT TOOL MATERIALS DURING EDM OF H 11 STEEL AT REVERSE POLARITY
Electric Discharge Machining (EDM) is a non-traditional machining process that involved a momentary spark discharges through the fluid due to the potential difference between the electrode and the workpiece. In EDM, improper choose of the electrode material may cause poor machining rate (or) performance. This is due to material removal rate characteristics. Less material removal rate (MRR) needs more time for machining process and become waste which is not good for production. Hence in this study, the effect of input parameters of EDM process ie. electrode type, peak current, gap voltage, and duty cycle on material removal rate of H11 steel are experimentally investigated. A L18 Taguchi’s standard orthogonal array is used for experimental design. Conventional Copper (Cu) and powder metallurgy (PM) copper tungsten (CuW) are used as tool materials. It was found that conventional copper tool electrode gives maximum MRR and best parametric setting for maximum MRR was found at, Cu (99% Cu) tool electrode, 9 ampere current, 50 volts gap voltage and 0.92 duty cycle. ie. A1B2C2D3.
Bharti EFFECT OF TOOL MATERIAL ON SURFACE ROUGHNESS IN ELECTRICAL DISCHARGE MACHINING
H11 die steel is widely used in forging dies, aircraft landing gears and shafts. Electric discharge machining (EDM) is one of the most suitable processes to shape this material. This work demonstrates the effect of pulse-on-time (Ton) on surface roughness during EDM of H11 tool steel by taking three different tool electrode materials. Experiments have been conducted by varying Ton in four steps (10 μs, 20 μs, 30 μs, 40μs) while keeping the values of other variables fixed. On the basis of experimental results, it is concluded that tool properties of electrode play a vital role in machining characteristics of die-sinking EDM process. The results demonstrate that Copper-tungsten electrode offers the best surface finish followed by graphite and copper electrode in EDM of H11 too steel.
Role of Impurities in Electric Discharge Machining
This paper summarizes the experimental and theoretical investigations to determine the effect of impurities in dielectric liquid on the Electric Discharge Machining performance.