Spark erosion is a direct discharge characterized by the following: before discharge, there is a high voltage between the two electrodes of the spark discharge, and when the two electrodes approach, the insulation between them is broken down, and spark discharge occurs. During the breakdown process, the resistance between the two electrodes drops sharply, and the voltage between the two poles also drops sharply. The EDM spark channel must be extinguished promptly after maintaining its transient state to maintain the "cold pole" characteristics of spark discharge (i.e., the thermal energy of channel energy conversion is not transferred to the depth of the electrode), which allows the channel energy to affect a small range. The energy of the channel can cause localized corrosion of the electrode. The method of material dimensional processing using the corrosion phenomenon generated during EDM spark discharge.
EDM spark erosion is a spark discharge in a liquid medium within a low voltage range. It has evolved into a comprehensive intelligent body of interdisciplinary, multi-disciplinary, and edge technology by integrating advanced technologies from various periods. The requirement for intelligence is entirely attributable to its elimination of human accidental factors, high reliability, low operating costs, and high production efficiency.
With the development of industrial production and the advancement of scientific and technological progress, new materials with high melting points, high hardness, high strength, high brittleness, high viscosity, and high purity are constantly emerging. There are more and more workpieces with various complex structures and special process requirements, which makes traditional mechanical processing methods unable to process or difficult to process. Therefore, in addition to further developing and improving mechanical processing methods, people are also striving to seek new processing methods. This method can adapt to the needs of production development and has shown many excellent performance in applications. Therefore, the EDM spark machine has been rapidly developed and widely used.
(1) The energy density of pulsed discharge is high, which is convenient for processing special materials and complex-shaped workpieces that are difficult or impossible to process with ordinary mechanical processing methods. It is not affected by material hardness and heat treatment conditions.
(2) The duration of pulsed discharge is extremely short, and the heat generated during discharge has a small range of thermal conduction diffusion, so the range of material heating effect is small.
(3) During EDM spark erosion, the tool electrode and the workpiece material do not come into contact, and the macroscopic action force between them is extremely small. The tool electrode material does not need to be harder than the workpiece material, so the tool electrode is easy to manufacture.
(4) It can reform the structure of the workpiece, simplify the processing technology, improve the service life of the workpiece, and reduce the labor intensity of workers.
Manufacturing stamping dies, plastic molds, forging dies, and die-casting molds.
Machining small holes, irregular holes, and threading holes in hard alloys.
Cutting parts on metal sheets.
Processing narrow slits.
Grinding flat and circular surfaces.
Strengthening the metal surface, removing broken tools, perforating quenched parts, directly processing complex parts with shaped surfaces, and so on.