Study On Temperature Field Simulation Of WEDM In Gas Based On Moving Heat Source

WEDM in gas has the characteristics of good surface quality, such as small surface roughness, the high straightness accuracy, the narrow discharge gap, no electrolytic corrosion, etc. The surface quality of the workpiece acquired by this kind of machining method is higher than those acquired in the liquid machining.Because of the different processing medium, the electrode discharge mechanism, the process characteristics of machining, the surface microtopography obtained in the gas machining are quite different from those acquired in the liquid machining. Therefore,it is very essential to study the removal processing mechanism and process characteristics of the gas machining.This paper studied the erosion mechanism of the processing. This paper studied the processing mechanism of gas discharge, this paper set up the heat transfer model of the workpiece based on moving heat source of single pulse discharge in WEDM,included the physical model and mathematical model. By using the finite element analysis software ANSYS, this paper analyzed the temperature field distribution of the Cr12 Mo V workpiece, the temperature field was varied with the electric parameters of WEDM which was used in gas machining, the temperature field distribution that acquired based on the fixed heat source and the moving heat source were compared and analyzed. According to the results of the simulation analysis based on the moving heat source, this paper established the mathematical erosion model of single electric pit, the single electric erosion pit was composed of the throw layer, white layer, bulge and heat affected layers and established the mathematical model to calculate the volume of each layer, calculated the volume under different electric parameters of each layer. According to the erosion thickness of the workpiece which was measured under different electrical parameters, this paper determined the stacking way of the electric erosion pits on the surface of the workpiece, this paper established the erosion model of the workpiece under continuous pulses, calculated the material erosion volume of the workpiece under different electrical parameters.On the basis of theoretical research, this paper carried out the processing experiment of WEDM which is carried out in gas medium. The mathematical model of theoretical calculation is established, the theoretical calculation data were compared with the measured data, this paper proved that the theoretical calculationmodel had certain predictability.The micromorphology of workpiece that acquired in gas medium and in liquid medium were compared and analyzed. Finally, this paper entered the experimental data into the formula proposed in this paper, the test data were compared with the simulation data, verified the rationality of the mode.In this paper, the mechanism of machining and the distribution of temperature field of the workpiece were studied, the removal theoretical model of the continuous pulses in the processing of gas is established. It is of great significance to study the the material erosion in gas and the optimization of the parameters in the finishing processing.