Modeling and analysis of surface crack in EDMed AISI D2 steel

In this investigation, Response Surface Methodology (RSM) is used to explore the effect of four controllable input variables namely: discharge current (Ip), pulse duration (Ton), duty cycle (Tau) and discharge voltage (V) on output variable Average Crack length (ACL) produced due to Electrical Discharge Machining (EDM). A central composite design is used for the estimation of the model coefficients of the factors, which are believed to influence the surface cracks produced due to EDM spark. Experiments were conducted on AISI D2 tool steel with copper electrode. The significant unknown coefficients of the proposed model are obtained and analysed by performing analysis of variance (ANOVA) at 5 level of significance. It is found that Ip is the most domination parameter with a degree of contribution of 87.39, and Ton, V and a few of their interactions also have significant effect on the surface cracks. The model sufficiency is very satisfactory as the coefficient of determination (R2) is found to be 99.7 that measures the proportion of variation in the response explained by the independent variables in the proposed model. © 2012 Nova Science Publishers, Inc.