Comparative Study of Powder Mixed EDM and Conventional EDM Using Response Surface Methodology

Powder mixed electrical discharge machining (PMEDM) is an advanced machining process. It is used for cutting hard material and for creating intricate shapes. In present work Inconel 825 is used as workpiece due to some of its unique properties like oxidation and corrosive resistance in high pressure and temperature environment as well as it retains its strength at higher temperature. The difficulty in machining it due to its fast work hardening is one of the reasons to use Electrical Discharge Machining (EDM) process is used in which there no direct contact of tool and workpiece so less chances of residual stress. To obtain the efficient output response parameter aluminium oxide (Al2O3) micro powder is mixed with dielectric was used. The input process parameters are gap voltage, pulse on time, powder concentration and peak current. The output process parameters are surface roughness (SR), material removal rate (MRR) and surface integrity. To analyse the surface morphology FESEM image is used. On the basis of application Inconel is used as studs in space shuttle, thrust chamber of rocket engine and engine combustion chamber etc. It has been observed that MRR and SR are directly influenced by the peak current (Ip),pulse on time(Ton) and gap voltage (GV).By using powder in dielectric surface roughness is improved as compare to conventional EDM process.