Research On The Electrode Wear And Analysis Of Gap Flow Field In Micro Holes-EDM

With the rapid development of scientific research and industrial technology,micro holes structure parts have been widely used.Micro-EDM technology has a great advantage in the micro-porous structure of the processing of parts because of its nonprocessing mechanical force,can be processed difficult to cut conductive materials and high machining accuracy.The machining accuracy of micro holes affect the use effect and service life of the parts,and the working conditions of fluid and electrode wear are the important factors affecting the micro holes machining accuracy.it is of great significance to study fluid conditions and electrode wear in Micro holes-EDM.In this paper,the research status of micro-holes processing at home and abroad is discussed firstly,and the processing characteristics of micro-group hole EDM are analyzed.The simulation model of gap flow field is established by using fluid simulation software.The velocity distribution of the clearance flow field in each processing stage is studied.Aiming at the middle stage of holes machining with the most complicated flow field,the influence of liquid flow rate,electrode speed and machining depth on the velocity distribution in the gap flow field was investigated.Based on the structural characteristics and working principle of micro EDM system,the micro electrode was fabricated by block electrode grinding and wire electrode grinding.In order to select reasonable fluid flow rate and electrode speed,micro holes EDM with different flow rate and electrode speed was studied experimentally.When the fluid flow rate increases,the aperture consistency and the quality of the entrance surface of the machined hole are obviously improved,and the machining efficiency of the micro hole is improved,and the electrode wear is reduced;When the electrode speed is increased,the chip removal capacity of the discharge gap is enhanced,the discharge environment is improved,and the efficiency of the micro hole machining is improved.The experimental results are in good agreement with the simulation analysis results of the machining gap flow field.In order to select suitable for micro holes machining power processing mode and electrical parameters,based on the analysis of multi-mode micro pulse power supply for micro EDM,the electrical parameters processing experiments under three power modes of RC,TC and TR are carried out.The influence of different electrical parameters on tool electrode loss,machining efficiency and discharge gap of micro pore was obtained.According to the experimental results,under the RC power mode,low voltage and large capacitance can be used to obtain better micro hole processing quality.After selecting the appropriate electrical parameters and processing parameters,the electrode wear law of micro hole EDM with different workpiece thickness and different tool electrode diameter was studied.It is found that the axial wear of the electrode increases linearly with the increase of the workpiece thickness and the number of holes in the tool when the tool electrode remains constant.According to the law,the compensation strategy of the electrode is studied,and a loss compensation strategy is obtained.In order to verify the effectiveness of the strategy,micro hole machining experiments were conducted using 100?m and 80?m diameter electrodes respectively.