Study of the Gaussian Distribution of Heat Flux for Micro-EDM

Gaussian heat flux boundary conditions are widely used to simulate the plasma in the electrothermal models for electrical discharge machining (EDM). However, the plasma thermophysical properties are different under different processing conditions. So it is important to find out the optimal Gaussian distributions of the heat flux for different electrothermal models. This paper suggests a Gaussian distributed heat flux to estimate the plasma heat source based on the law of energy conservation. A parameterized electrothermal model has been developed with the finite element method. By solving the developed model, the temperature field in the workpiece material is calculated. Then the crater radius and depth are estimated based on the calculated molten cavity. Afterwards, the simulated results are compared with the results obtained from single discharge experiments and the optimal Gaussian distribution is determined according to the least mean square error principle. The result shows that the optimal parameter value for micro-EDM is 1.25.