Author : K.L.Uday Kiran, G.Chandramohan Reddy , A.M.K.Prasad and R.Rajendra

Electrical discharge machining is considered as one of the main non-conventional machining processes used for manufacturing geometrically complex or hard material parts that are extremely difficult to machine by conventional machining processes. The process involves a controlled erosion of electrically conductive materials by the initiation of rapid and repetitive spark discharges between the tool and work piece in the presence of dielectric medium. The most important process parameters in EDM are material removal rate, electrode wear and surface roughness. The present work is focused to obtain a comprehensive study of surface roughness parameters (Ra, Rz, Rzmax & Rsm) of work materials at different currents in sink EDM process. The experiments were carried out on Al & Die steel components at different currents using cu as a common tool material. The surface roughness parameters under study included average roughness (Ra), average maximum height of the profile (Rz), maximum roughness depth (Rzmax) and the mean spacing of the asperities (Rsm). Machining time of each component and micro hardness of the work pieces before and after machining ware also obtained. In this work the Surface integrity was characterized by roughness parameters and micro hardness values. The results of this investigation revealed that the surface roughness parameters, machining time and micro hardness of work pieces were influenced by current and could be utilized to achieve desired quality of surface finishing thereby increasing the EDM efficiency.

Keywords: EDM, Micro hardness, Machining time, Surface integrity, Surface roughness parameters.

Article published in International Conference on Advances in Mechanical Sciences 2014, Special Issue-2 (Feb 2014)