Optimization of surface roughness by MOORA method in EDM by electrode prepared via selective laser sintering process

Abstract

Electrical discharge machining (EDM) is a non-traditional machining process widely used in the machining of difficult to machine materials. The EDM process is extensively use in aerospace, biomedical, die and mold making industries. In this present work, EDM of AISI 1040 stainless steel work piece has been performed by using three different types of tool electrodes like AiSiMg electrode prepared via selective laser sintering (SLS) process along with conventional copper and brass tool electrodes and EDM 30 oil as dielectric fluid. The SLS process is a rapid prototyping (RP) process also called as additive manufacturing (AM) process, which can be used to produce complex shape tool electrode from metallic powder by melting and sintering with the help of laser power. The EDM is performed by varying different process parameters like discharge current (Ip) and pulse-on-time (Ton). The surface roughness parameters like average roughness (Ra), maximum height of the profile (Rt) and average height of the profile (Rz) are measured by the use of surface roughness measurement machine. To reduce the number of experiments, design of experiment (DOE) approach like Taguchi’s L9 orthogonal array has been use. The surface properties of the EDM specimen are optimized by MOORA method and the best parametric setting is reported for the EDM process. Type of tool is found to be the most significant parameters followed by discharge current and pulse-on-time. The AlSiMg RP electrode gave best surface finish followed by brass and copper. With increase in discharge current and pulse-on-time, the surface roughness value of the EDM machined surface increased. So, it preferable to use lower setting of discharge current and pulse-on-time along with AlSiMg RP electrode to get better surface finish EDM machined specimens.