Fundamental Research On Electrochemical Discharge Machining With Tool Electrode Ofhigh Speed Rotation

The micro-holes are important structures which are widely used in fields of engineering or science related to aerospace, medical science, auto industry and micro electronics, etc. Electrochemical discharge machining(ECDM) with high speed micro electrode is a micro machining process based on the fundamental of electrochemical discharge principle. The process has been applied to drilling of metal micro holes. In this dissertation, some key technologies in electrochemical discharge machining with tool electrode of high speed rotation are studied. This paper discusses the high-speed rotation of the tool electrode electrochemical discharge machining process, and analyzes how to generate the gas film on the tool electrode when the tool electrode rotates at high speed. In addition, the cover area of the gas film on the tool electrode increases as the rotating speed of the electrode increases. The feasibility of adopting the wavelet transform is discussed to analyze the current of ECDM. It can be concluded that the analysis of the electrochemical discharge machining process using the wavelet transform can deepen the understanding of the process. The results indicate that the processing is more stable at the higher tool electrode rotating frequencies. A set of electrochemical discharge machining platform system was established. Moreover, the real-time control and data acquisition system of electrochemical discharge machining was developed using devices of virtual instruments, and the software of the system was designed based on Labwindows/CVI. Meanwhile, a conductive device was invented, which ensured a constant supply of electricity in the process of electrochemical discharge machining. Besides, the method of adopting the sensor to control the machining gap was proposed. A series of electrochemical discharge machining experiments which used the spiral tool electrode to drill micro holes on the 304 L stainless steel with the water as the working liquid were conducted. The effects of rotation rate on machining accuracy, surface roughness and electrode loss were mainly investigated. Finally, the 200 micrometers screw cylindrical shape of tool electrode was implemented in drilling micro holes with high shape accuracy, good surface quality and depth to diameter ratio of 8. This dissertation is the further study about the high-speed rotation of the tool electrode electrochemical discharge machining process in the nontraditional micromachining field, which is available for machining high performance materials. The application of this technique in the fabrication of metal microstructure will be helpful to promote the development of electrochemical discharge machining process.