Medium Wire Cutting Machine Tool Working Fluid

Functions and precautions of working fluid for wire cutting:
The premise of stable cutting of EDM wire cutting must first ensure that the wire is not broken during the cutting process. The probability of wire breaking increases mainly with the increase of discharge energy and cutting thickness, that is, it is closely related to the ion bombardment, cooling state and residence time of the electrode wire in the discharge channel. The cutting efficiency and surface roughness are also related to inter-electrode cooling and deionization and restoration of insulation state. When an emulsion containing about 5% of mechanical oil is used as the working medium, there are two phenomena on the surface of the cut workpiece after cutting: first, the cut specimen is adhered to the substrate, and generally it takes force or even knocking to separate it from the substrate; second, the surface of the cut specimen is covered with sticky or even powdery etching products, which need to be cleaned with kerosene. This is mainly accompanied by a high temperature of more than 10000°C in the discharge channel. The working medium will decompose to generate a large amount of polymer compounds and react with the metal etching products to generate colloidal or granular substances. These substances will adhere to the slit and accumulate mainly at the slit exit, seriously affecting the removal of electro-erosion products and making it very difficult for fresh working medium to enter the slit. Since there is no guarantee of a constantly updated working medium between the two electrodes, this will directly affect the continuation of normal discharge, even the discharge in the gap mixed with a large amount of colloidal substances, and even produce arc discharge, so that the workpiece and the electrode wire surface cannot be cooled in time, the insulation state is abnormal, resulting in a decrease in the normal discharge ratio, a decrease in cutting speed, burns on the workpiece surface, severe commutation stripes and deterioration of processing quality, and damage to the electrode wire, causing wire burning in severe cases. Therefore, the use of emulsion as the working medium has a great influence on the improvement of the cooling state in the inter-electrode channel, deionization and restoration of the insulation state, and the higher the workpiece, the slower the wire speed, the longer the electrode wire stays in the processing area, and the probability of wire breakage will naturally increase. It is an inevitable phenomenon that the emulsion decomposes into colloidal or granular substances in the discharge channel, so the use of emulsion as the working medium will inevitably greatly limit the improvement of cutting process indicators. The most direct consequence of the deterioration of inter-electrode cooling is that WEDM-HS must use very conservative discharge energy in exchange for unbroken wire processing.