Study On Machining Mechanism And Technology Of Micro - Electrolytic Milling Based On Ultrashort Pulse Current

Electrochemical machining is a machining method that anode work-piece is eroded byelectrochemical reaction to machine work-piece. In the course of electrochemical machining，metal material is removed by ion dissolution continuously，the tool electrode and the machinedwork-piece don’t contact, which cause no cutting force, deformation and residual stress on thesurface of the machined work-piece．By using ultra-short pulse current, the locality ofelectrochemical machining is well controlled to make electrochemical machining become aneffective micromachining method. Manufacturing technology in the future is evolving to theera of miniaturization trend，metal micromachining is a problem, and thus the studies ofelectrochemical machining of metal possess the significance.Micro electrochemical milling can machine the designed3D microstructure by a simpletool electrode(cylindrical，spherical，etc) under CNC system control according to the NCprogram，liking mechanical milling. In this paper，by studying work principle of electricaldouble layer of electrochemical micromachining, how layer thickness of milling have an effecton the accuracy of the shape and position is elaborated. By analyzing the mechanism of ultra-short pulse electrochemical milling，the electrochemical micromachining system is designed.The factors affecting electrochemical micromachining are analyzed in this paper, includingforce, electric field and flow field between the electrode gaps in the process of electrochemicalmicromachining. Then, the flow field conditions are simulated and the influences of the rotatingelectrode speed upon micro electrochemical milling are studied, which provides theoreticalbasis for micro electrochemical milling.Micro electrochemical milling system includes the machinery unit and electrical unit. Theonline fabrication module of tool electrode，the worktable，the online observing apparatus，servo feed mechanism and so on constitute the mechanical unit. The ultra-short current powersupply, the electrical unit is constituted by the checking circuit of machining conditions, theprotection circuit of power supply and so on.Finally, the process of ultra-short pulse current electrochemical micromachining is studied,including drilling micro-hole and milling micro-structure. By designing micro millingelectrolysis servo feed mode，the feasibility experiments of micro electrochemical milling and the layered electrochemical milling are carried out to machine the complex microstructure,and the better experimental results are achieved.