Electric spark treatment has in liquid medium, the automatic feed regulating unit of the machine tool makes suitable discharge space maintains between workpiece and tool electrode, very strong pulse tension should bring to bear on between tool electrode and workpiece (the puncture voltage of the medium in obtaining clearance) when, lowest of intensity of insulation of meeting puncture medium is in, if plan institute is shown. Because discharge area is very small, discharge time is extremely short, so, energy height is centered, make the temperature instantaneous of discharge area is as high as 10000-12000 ℃ , the metal of workpiece surface and tool electrode surface is local and fused, even vaporization evaporates. Local and fused the metal with vaporization is cast into working fluid below the action of explosive force, be cooled to be metallic little grain, be rushed quickly to leave working area by working fluid next, make workpiece surface forms a tiny indentation thereby. After discharging, the insulation intensity of medium restores to wait to discharge the next time. Make workpiece surface is divided by corrode ceaselessly repeatedly so, duplicate on workpiece the appearance that gives tool electrode, achieve the goal of processing thereby. Treatment of electric spark of pump of filter 7- of 6- of fluid of job of 5- of electrode of tool of 4- of device of automatic feed of 3- of power source of pulse of 2- of workpiece of 1- of graph of principle of electric spark form cutting is the process that ceaseless discharge corrode eliminates a metal. Although the time of pulse discharge is very short, but it is electromagnetism, thermodynamic the process that uses with hydromechanical collaboration waiting for put together, it is quite complex. Rise integratedly, the process that pulse discharges can divide for the following phase: (The formation of the ionization of the medium between 1) pole, puncture and discharge passageway brings to bear on when pulse voltage between tool electrode and workpiece when, polar between form an electric field instantly. Electric field intensity and voltage become direct ratio, become inverse ratio with the distance, as extremely of voltage lift or be extremely span leaves reduce, extremely electric field intensity also will as increase. Because the microcosmic surface of tool electrode and workpiece is scraggly, extremely span leaves very small, consequently extremely electric field intensity is very inhomogenous, polar the electric field intensity of the prominent place that leaves the nearliest or a most advanced place is commonly the biggest. Increase when electric field intensity a certain quantity of when, medium by puncture, discharge clearance resistor reduces a few ohm quickly from insulation condition, clearance electric current rises quickly to maximum. Because passageway diameter is very small, the current density in the passageway is very so high. Clearance voltage drops quickly by puncture voltage scintilla maintaining voltage (it is 20~30V about commonly) , voltaic criterion by 0 rise to electric current of some peak value. (Fused, vaporization heats up material of 2) medium pyrolysis, electrode expand extremely medium once by ionization, puncture, after forming discharge channel, pulse power source makes the electronic high speed between the passageway runs quickly to positive electrode, ion runs quickly to negative pole. Electric energy becomes kinetic energy, kinetic energy is heat energy through colliding to transform again. Become instantaneous heat source respectively in the anode inside the passageway and negative pole surface then, reach very high temperature. Passageway high temperature will work fluid medium vaporization, then hot tearing decomposes vaporization. The working fluid after these vaporization and metallic vapour, instantaneous bulk jumps, bleb is become inside discharge clearance, rapid heat expands and have explosive character. Observe electric spark machines a process, can see bleb appears between discharge clearance, working fluid blackens gradually, hear slight and ringing detonation. Electric spark treatment basically relies on heat to expand standoff ministry small explosion, make fused, vaporization electrode material casts a corrode to divide. (Of 3) electrode material cast a passageway and high temperature of instantaneous of dot of discharge of negative pole surface makes working fluid vaporization and metallic stuff fused, vaporization, heat expands the instantaneous pressure with very high generation. The pressure of passageway center is highest, make vaporization gas expands outwards ceaselessly, the melt metal liquid of pressure altitude and vapour, be elbowed out, cast in go out and entering working fluid. As a result of the action of exterior tension and cohesive force, make cast the data that give to have the least face to accumulate, the agglomeration when condensation becomes petty pellet grain. Fuse and vaporization the metal is in cast when leaving electrode outside, to splatter everywhere, outside little grain contracting in throwing working liquid except the majority, still one fraction splatters, the electrode that plating Fu, adsorption is on apparently. This kind splatters each other, plating Fu and adsorptive phenomenon, can use below certain condition decrease or compensation tool electrode is machining the loss in the process. Actually, the corrode of metallic stuff is divided, throw a process more complex, current, people still is in to the understanding of this one complex mechanism in be being deepened ceaselessly. (The disappear ionization of the medium between 4) pole the end as pulse voltage, pulse electric current falls quickly also for 0, but after this still due a paragraph of time interval, make ionization of clearance medium disappear, discharge namely the electrified particle in the passageway is compound for neuter particle, restore this second discharge passageway to be in the insulation intensity of medium, and reduce electrode surface temperature to wait, lest always repeat next time,bring about electric arc to discharge, assure to be in thereby polar place or resistor lead the smallest part to form recently the next time puncture discharge passageway. This shows, to make sure electric spark machines a process normal ground undertakes, want to have enough pulse time interval commonly between two pulse discharge. In addition, still should take superabundant land, make puncture, discharge nods dispersive, move, discharge around only otherwise, easy form electric arc. CNC Milling