Modelling and analysis of EDMED job surface integrity

During machining of metals by electrical discharged machining (EDM) process a large amount of heat is generated for which the surface characteristics of the metals are affected. But this phenomenon is unavoidable during the machining of metals by EDM process and some technical problems remain unsolved in the area of surface integrity of the machined workpiece. The present study emphasizes the features of the development of comprehensive mathematical models based on response surface methodology (RSM) for correlating the interactive and higher-order influences of major machining parameters i.e. peak current and pulse-on duration on different aspects of surface integrity of M2 Die Steel machined through EDM. The paper also highlights the various test results that also confirm the validity and correctness of the established mathematical models for in-depth analysis of the effects of EDM process parameters on surface roughness (SR), average white layer thickness (WLT) and surface crack density (SCD). The detailed analyses of the SEM micrographs and the graphs plotted on the basis of experimental results also reveal the correctness of the developed mathematical models. Further, optimal combination of these parameters has been evaluated and it can be used in order to minimize various criteria of machined surface integrity.