The erosion thread is an essential component in wire electric discharge machining (EDM), used for high-precision cutting and shaping of metal parts. It is a thin metal wire, usually about 0.25 mm in diameter, made of materials such as copper, brass, molybdenum or tungsten. This wire serves as an electrode that, through controlled electrical discharges, erodes the material of the workpiece, allowing the creation of complex shapes and precise dimensions.

Working principle

In the wire erosion process, the erosion wire passes through the workpiece without making direct contact with it. A pulsed electrical voltage is applied between the wire and the workpiece, which creates a spark discharge with a high temperature (between 8000 and 12,000°C). This heat melts and vaporizes small particles of the material, forming the desired shape with extreme precision. The dielectric fluid, usually deionized water, cools the machining area and washes away the detached particles, keeping the process stable and efficient.

Characteristics of the erosion thread

•Diameter: The standard diameter is 0.25 mm, but threads with a diameter of 0.15 mm to 0.3 mm are also used, depending on the precision requirements and the thickness of the material.

•Material: Copper or brass filaments are most commonly used due to their good electrical conductivity and wear resistance. For specific applications, molybdenum or tungsten filaments are used.

•Tensile strength: High tensile strength (e.g. 1000 N) ensures stability and minimizes the risk of breakage during processing.

•Coverage: Some threads have special coatings, such as zinc, that improve cutting speed and surface quality.

Applications

EDM wire is widely used in various industries where high precision and complex shapes are required:

•Production of matrices and injection moulds: Creating complex contours and details with high precision.

•Aerospace industry: Machining of high-strength alloys and components with critical tolerances.

•Medical equipment: Manufacture of precision instruments and implants.

•Electronics: Production of components with microscopic dimensions and high precision.

Advantages of using an erosion thread

•High precision: Allows the production of parts with tolerances up to ±0.015 mm.

•Processing of hard materials: Effective on metals with high hardness that are difficult to process with conventional methods.

•Minimum mechanical stresses: The lack of direct contact reduces the risk of deformations and internal stresses in the material.

•Automation capability: Modern EDM machines allow for continuous operation without constant supervision, increasing productivity.

Maintenance and selection of erosion thread

The correct selection of wire is essential for the optimal performance of the EDM machine and the quality of the final product. Factors such as material, diameter, tensile strength and coating must be considered in accordance with the specific requirements of the project. Regular wire replacement and machine maintenance ensure process stability and extend the life of the equipment.