EFFECT OF MACHINING PARAMETERS ON SURFACE ROUGHNESS IN μ-EDM OF CONDUCTIVE SiC

摘要

Micro-electrical discharge machining (μ-EDM) is a non-traditional manufacturing technique that has been widely used in the production of precision engineering components throughout the world in recent years. The most important performance measure in μ-EDM is the surface roughness. The Silicon Carbide is a reaction bonded advanced ceramic that is the fourth hardest material after Diamond, boron nitride and boron carbide. Due to low fracture toughness, machining of Silicon Carbide is accomplished with EDM. In this study, the experimental studies were conducted under varying gap voltage, capacitance and threshold. The numbers of experiments were reduced by L9 array of Taguchi's theory of DOE. Signal-to-noise (S/N) ratio was employed to determine the most influencing levels of parameters that affect the surface roughness in the μ-EDM of conductive silicon carbide. To validate the study, confirmation experiment has been carried out at optimum set of parameters and predicted results have been found to be in good agreement with experimental findings. A fuzzy logic model for predicting surface roughness during μEDM was also developed on MATLAB software and the goodness of fit of predicted values with experimental values was tested using chi-square test.