Fundamental analysis of EDM die-sinking applying different tungsten carbide

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The selection of an appropriate tool electrode material for die-sinking electrical discharge machining (EDM) is connected to different boundary conditions. An economic production requires high material removal rate V̇W with minimal relative tool wear ϑ at the same time. Thus, the physical removal principle results in a need for a high electrical conductivity κ, thermal conductivity λ, specific heat capacity cp and a high melting point TS to ensure the best possible discharge characteristics and heat dissipation at the tool electrode. Manufacturing of complex and fine structures like thin bars with low wall thicknesses dW requires a sufficient mechanical strength E of the material. The material properties of tungsten carbide are ideal for the application in EDM. Due to the high effort in machining tungsten carbide, the manufacturing of form electrodes made of tungsten carbide has been neglected so far. The aim of this research project is the validation of different tungsten carbide specifications as tool electrode material for EDM as well as identifying appropriate process parameters for macro- and micro- machining of steel materials. The scientific analysis of the experimental results leads to extensive findings in the area of EDM by analysing the different tungsten carbides and their corresponding process behaviour in EDM. The acquired knowledge and the specific material characteristics of the WC-Co carbide enable the improvement of important process characteristics like material removal rate V̇W and electrode wear ϑ in die-sinking EDM.