Thermal energy distribution and optimization of process parameters during electrical discharge machining of AISI D2 steel

Abstract

Electro discharge machining has gained significance because of wide range of advantages like cutting variety of material and its alloys with complicated shapes and high accuracy. The effectiveness of electro discharge machine can be calculated in terms of material removal ness, relative tool wear ratio, surface roughness, etc. The total electrical energy is transferred into various parts like work piece, tool, dielectric fluid and energy in eroded particle from both tool and work piece. By calculating energy transferred to each at different parameters we can optimize it in order to get the required parameter for the specific requirement. Since one of the most important aspects of EDM is to machine intricate shapes, in this case the prevention of tool erosion is very much important factor. By using simple conduction equations, we can calculate the energy transferred to each for material removal rate and tool wear rate. Also energy transferred to work piece, tool can be calculated by using conduction equation and the best suited input parameters can be found for the maximum energy transfer to work piece. In this research, a complex shaped tool was fabricated and machining operation was done at different input parameters in order to get the same impression of the tool on the work piece. After than energy responsible for tool wear were calculated and the optimum parameter are found in order to minimize the tool wear. The change in shape of tool, reduction of the area also observed after several experiments. Various graphs showing the variation of fraction of energy transferred to tool, work piece are plotted. Variation of material removal rate and tool wear rate, surface roughness with the input parameter are plotted in the graphs. Thus from the graphs, optimum parameters can be found in order to know which set of parameters suits for the desire output and can be applied in industry for the same purpose.