Research On Discharge Characteristic Of Electrode Gap In Electro-arc Machiing

In the aerospace field,in order to ensure that key parts meet the requirements in extreme environments and reduce the weight of parts,titanium alloys and Superalloys which have stable material properties and excellent specific strength are often used.The electro-arc machining is used for rough machining of the part blanks,which solves the problems of high processing cost and long manufacturing cycle of difficult-to-cut materials.However,in the multi-axis arc machining,the selection of machining process parameters become difficult,because of lacking theoretical research on the discharge state between electrodes under electrode deflection.In order to solve this problem,this paper analyzes the flow field and electric field between the gap in variable-axis arc milling,develops the process experiment of the variable-axis arc machining.The theoretical research on the characteristics of discharge state under variable-axis arc milling is perfected.Laid the foundation for the optimization of processing technology.In order to disclose the influence of electrode deflection on the discharge effect of debris,the flow field between the gap was simulated and analyzed by using computational Fluid Dynamics(CFD).By analyzing the changes of the main processing area between the gap,under different electrode deflection directions.Geometric models of the electrode deflection along the X axis,the electrode deflection along the Y axis in the positive direction,and the electrode deflection along the Y axis in the negative direction are established respectively.The simulation analyzes the effects of different deflection angles on the flow field.Finally,the influence of the change of the flow field on the discharge effect of the debris is discussed.The simulation software is used to simulate the electric field of the inter-electrode gap.Which disclose the change of the discharge state between poles in the process of variable-axis arc milling.According to the distance change of the gap in the the variableaxis arc milling.The gap geometric models of the initial contact discharge and the electrode completely sinking into the workpiece are established respectively.The simulation software is used to analyze the influence of the deflection angle and the debris on the electric field distribution between the electrodes.Finally,based on the simulation results,the influence of the electric field change on the discharge state between the electrodes is discussed.A series of comparative experiments were designed to verify the change of the state between the electrodes with the deflection of the electrode in the simulation of the flow field and the electric field and its influence on the performance of the machining process.The comparison experiments of groove machining were carried out under different deflection angles,and the effects of deflection direction and deflection angle on machining time,electrode loss,thickness of recast layer and discharge waveform were analyzed.The experimental results show that the effects of different deflection directions and deflection angles on the electrical discharge machining process are confirmed by the analysis results of the flow field simulation.Utilizing the chemical properties of titanium alloys that produce anodizing discoloration reactions during the discharge process,it is designed to discharge the surface of titanium alloy materials with a specified number of pulses under different deflection angles,pulse peak currents and impulse pressure conditions to obtain discharge traces under different conditions.By measuring the color distribution of the discharge traces,the influence of different parameters on the electric field distribution between electrodes is obtained.The experimental results show that the effects of different deflection angles and the size and concentration of the debris on the discharge state between electrodes are consistent with the electric field simulation results.Finally,designing a rudder surface model.Using UG post-builder to generate processing G code to rough and semi-rough superalloy.It is verified that the electro-arc machining has a good application in the curve surface structure processing.