Study of WEDM Process on Surface Roughness of H-11 (Hot Die Steel)

Abstract

Wire electrical discharge machining (WEDM) process is a unique option for machining of conductive material with highest accuracy. But it is not easy to determine optimal parameters for the best performance because of its complex process. Hence the study for analyzing the performance parameters needed before their optimization to get maximum performance. Objectives of this analysis study was to investigate and evaluate the effect of selected input parameters for machining of Hot die steel H11 (work material) which is used in die casting dies, aircraft landing gears, helicopter rotor blades and many more applications. The effect of process parameters like pulse on time, servo voltage and peak current on surface roughness response had been considered for each experiment. Further, experimentation was planned as per L27 Orthogonal array provided by Taguchi method for Design of Experiments (DOE). Brass wire electrode with 0.25mm diameter was used as tool in the experiments. The experimental results were analyzed and explained with the help of plotting linear and surface graphs between various parameters. The combined contribution of the process parameters were also plotted and explained with the help of 3-D graphs. SEM test was conducted to validate the result with measured values of surface roughness of machined surfaces. It was found that all the three input parameters selected were significant and contributed maximum performance at a particular value.