The effect of the discharge of the EDM machine on the mold is related to the following operations. Here are some factors that can improve the spark machine mold discharge effect. The reasonable distance between the spark machine tool electrode and the workpiece, the pulse discharge channel, the pulse energy density, the discharge gap, the dielectric, and the time are comprehensively explained, which can be used as a reference for everyone in using the spark machine discharge.
Within this distance range, the pulse voltage of the CNC EDM machine can meet the requirements of pulse breakdown of the dielectric to produce spark machine discharge, and can also meet the requirements of discharge of the corrosion products after the dielectric deionization and the spark channel extinguishing. If the distance between the two electrodes of the spark machine is too large, the pulse voltage cannot break through the dielectric and discharge. If the two electrodes are short-circuited, there is no pulse energy consumption between the two electrodes, and electrochemical machining cannot be achieved.
The spark machine pulse discharge needs to be repeated multiple times; two adjacent pulses form a channel in different points. Secondly, if the spark machine pulse discharge occurs in a certain area over a certain period, then the pulse discharge should be transferred to another area at another time. This can avoid carbon deposition and avoid arcing and local burns.
The pulse energy density transmitted between the two electrodes should be large enough. After the spark channel is formed, the pulse voltage does not change much, so the current density of the channel can represent the energy density of the channel. Only if the energy density is large enough, can the local melting or vaporization of the processed material be achieved to form a corrosion trace(such as pits) on the surface of the processed material, and discharge machining of the CNC spark machine can be achieved. The electrochemical corrosion products produced after pulsing can be discharged out of the discharge gap in time, making repeated pulsing smooth. In the production practice of the spark machine, the above process is completed in two ways.
The inherent characteristics of spark discharge and electrochemical corrosion can remove corrosion products; in addition to etching materials, other discharge products(such as steam from the dielectric) can also promote the above process.
Some manual auxiliary process measures must be adopted, such as circulating and filtering of working fluid, flushing and pumping measures used in processing, etc.
It is necessary to fill the dielectric between the two electrodes of the spark machine. In the electrical discharge machining of materials, liquid dielectric(special working fluid or industrial kerosene) is used between the two electrodes, and gaseous dielectric is used between the two electrodes when the spark machine intensifies the material surface.
The spark machine discharge must be short-time pulse discharge. The discharge time is generally10-7-10-3s. The discharge time is short, and the thermal energy generated during the discharge diffuses too late to the inside of the processed material, thereby limiting the energy to a small range and maintaining the cold spark discharge characteristics of the spark machine.The CNC EDM machine has certain requirements and characteristics, and reasonable use of these characteristics of the spark machine in work can achieve better results for the spark machine effect of the mold, and make the use of the spark machine smoother.