Optimization of Wire Electro Discharge Machining Parameters for Improving Surface Finish of Cryo-Treated Tool Steel Using DOE

Obtaining good surface finish in tool steels by conventional machining is a difficult task. Nontraditional material removal processes, for example, wire electro discharge machining (WEDM), are very useful for precision manufacturing. In WEDM, it is very difficult to choose the correct combination of machining parameters and materials. Traditionally, heat treatment process is used for improving the hardness of tool steels, whereas cryogenic treatment is used as a secondary treatment to enhance the hardness as well as the wear properties. In this work, the effect of WEDM parameters on surface finish of cryo-treated AISI D2 tool steel is investigated. Taguchi DOE methodology is used for designing and conducting the experiments. The surface roughness was considered a response for improving surface quality. ANOVA is used to optimize the machining process for better surface quality. A mathematical model is developed for predicting the response quality using regression analysis. Further experiments were conducted with optimized parameters to authenticate the usefulness of the proposed model. The confirmation experimental result shows that the model suggested by the Taguchi's method is suitable for improving the surface quality by reducing the surface roughness.