In the wire EDM manufacturing process, at the moment the cutting begins, the dielectric fluid between the workpiece and the wire electrode prevents the formation of an electrical arc. However, as the voltage increases, the electric field between the electrode and the workpiece reaches its maximum level. When the voltage becomes sufficiently high, ionization of the fluid in the gap occurs, and once the voltage peaks, an electric current begins to pass through a narrow channel.
As a result of the heat generated, a vapor channel is formed in the gap. Near the end of the discharge duration, the direct current and voltage stabilize, and the temperature and pressure within the channel reach their peak, causing a small amount of metal to be removed from the workpiece.
At the beginning of the off-time (pause period), the current and voltage drop to zero, causing the vapor channel to collapse. The molten metal is then flushed away from the workpiece by the dielectric fluid. At the end of the process, residual particles formed during the pause period are removed from the gap, allowing the area to cool down.
These discharge cycles are repeated successively several times to remove material gradually.
In addition to understanding what wire EDM is, it is also important to know the materials used in the wire EDM process. The wires typically used are made of brass, molybdenum, tungsten, and copper, with diameters ranging from 0.05 mm to 0.4 mm.
Cutting Stage in Wire EDM
In the first step, the workpiece is placed in the machine’s processing area, and a wire electrode is fed from a spool of wire placed on the workpiece. Electric current is passed between the electrode and the workpiece. This electric current creates high-intensity heat and causes erosion on the metal surface.
This erosion process occurs by advancing the wire electrode in a controlled manner. The wire is cut according to movements programmed by the CNC system and slowly moved across the workpiece to create the desired shape. The process is managed through frequent measurements and inspections to ensure precise and repeatable results.
In conclusion, wire-cut erosion machines are a CNC technology used for precision part production. Based on the principle of electroerosion, they use an electric current between a wire electrode and the workpiece to erode the metal surface and create the desired shape. This allows for the production of complex precision parts.
