Semi-empirical model of efficiency of wire electrical discharge machining of hard-to-machine materials

In this study, the efficiency of wire electrical discharge machining of hard-to-machine materials was investigated experimentally. Uncoated brass wire, 0.25 mm diameter, zinc oxide coated brass wire and brass CuZn20 coated brass CuZn50 wire were utilized in the conducted research. The following variables were chosen as important WEDM parameters: discharge time ton, average working voltage U. The following properties of machined materials, such as: melting point Tt, electrical conductivity σ, thermal conductivity K, thermal expansion coefficient k, density ρ, heat capacity cp, were selected to develop the semi-empirical model of volumetric efficiency of WEDM. The variation of the WEDM efficiency in cutting different materials and applying different wire electrodes and different process parameters was modelled semi-empirically by employing dimensional analysis.