Learn about wire edm machining

Electric discharge wire cutting is a very precise manufacturing process, which is an electric heating production process. The use of discharge to remove material from workpieces has become the mainstream in the industry. It is compatible with almost all conductive materials and can create complex shapes and designs. 

In 1943, Soviet engineers developed the first electric spark wire cutting machine. This is an extremely precise machine that can corrode materials that are originally difficult to process. Later, American engineers developed a spark corrosion machine that could only discharge about 60 times per second. With its continuous development, a vacuum tube pulse generator was finally used, which can generate thousands of arcs per second. Later, in 1967, the Soviet Union developed the first successful wire cutting electric discharge machine. By the 1980s, these machines could run at a speed of 64 square millimeters per minute, becoming a very practical processing method.

So component manufacturers from multiple industries are using it, especially in fields such as automotive, medical, aerospace, etc.

Wire EDM machines focus on complex two-dimensional shapes. Many 5-axis machines are capable of cutting very complex shapes. Wire EDM is particularly useful in processing hard materials from raw materials to finished products, but it also has some inherent drawbacks. For example, it is not applicable to composite materials, plastics, and non-conductive natural materials.

Wires cannot be reused. It moves the workpiece while the machine cuts it, making it highly accurate. The spark gap formed by the arc is usually very small, and the welding wire does not really come into contact with the workpiece. It can cut almost all metals. It is more suitable for pre hardened mold steel, tungsten, molybdenum, titanium, and austenitic stainless steel.

Although it is possible to cut them, it is not the best method for cutting soft materials such as copper, bronze, brass, or non hardened steel, which can be processed using cheaper machines and methods.

If you want to manufacture a part without heating, electrical discharge machining may be your only option. It uses shaped electrodes, typically made of copper or carbon, to cut complex localized 3D cavities. This process involves pulse electrodes, allowing for cooling and rinsing, which is a good method for making complex shapes in molds and die-casting tools. It works well on pre hardened materials, reducing costs and preventing possible tool deformation.

  Wire

The wire in a wire cutting machine is used as a tool electrode. It is usually made of materials such as brass or coated copper, with excellent conductivity and the ability to withstand spark thermal stress. The diameter of the wire can vary, which can affect the cutting accuracy and surface smoothness.

 Dielectric

Generally a fluid with multiple functions, it isolates the wire electrode from the workpiece to prevent premature discharge. Also serves as a coolant, controlling the temperature of the cutting area, washing away eroded materials, and ensuring that there are no debris in the cutting area. The most commonly used is deionized water, while oil is also used for specific situations that require finer surface finish. The choice of fluid can greatly affect efficiency and the quality of processed parts.

 Power supply

Provides support for the machining process by adjusting the voltage and current required to generate sparks for cutting. The power supply unit (PSU) is used to provide precise discharge between the electrode and the workpiece. Enable wire electrical discharge cutting to cut conductive materials with minimal physical contact and reduce workpiece wear. Functions include: voltage control, pulse control, and thermal management.

 CNC cutting tools

Control the entire operation of the wire electrical discharge machining process. And it can automatically manage the cutting process. The precision of the cutting tool determines the level of error and processing time.

 Wire guide device

It is a precision component in wire cutting machines that plays a significant role in maintaining the accuracy and stability of wires. Due to its hardness and wear resistance, wire guides are usually made of diamonds or sapphires. Functions and importance include: wire stability, precise alignment, wear resistance (high-quality materials reduce the need for frequent replacement and maintenance)

 Flushing pump system

circulates dielectric fluid around the cutting area to wash away metal particles and contaminants from the gap between the metal wire and the workpiece. It is very important to maintain the integrity of the cutting and prevent short circuits.

 Filter system

It filters out metal particles and debris generated during the cutting process, ensuring that the dielectric fluid remains effective in the cutting environment.

 Servo control system

Adjust the position of the steel wire based on feedback from sensors to ensure that the wire maintains the correct path according to instructions.

 Workpiece fixing fixture

Fixing and positioning the workpiece during the machining process. Correct fixture settings are particularly important for ensuring accuracy, especially when processing complex parts.

 Cooling system

The cooling system controls the temperature of the dielectric fluid. Maintaining the correct temperature is crucial for preventing thermal deformation and optimizing machine performance.

 Damage detection system

monitors the condition of the wires, and if a wire breakage is detected, the machine will automatically stop. This helps prevent damage to the workpiece and reduce machine downtime.

Wire EDM has various applications and is used in many industries. The size and shape do not limit its use, as it can process long or extremely small parts. Traditional electrical discharge machining can handle harder and thicker materials.

The advantage of wire cutting with electric discharge is that it can cut accurately. Suitable for creating complex designs and shapes that are difficult to produce using traditional CNC machining. It is suitable for processing small parts and cutting highly delicate items, which are too delicate for other processing options. Wire EDM machining is an ideal choice for fragile materials that cannot withstand processing stresses and will not leave burrs or deformations.

The disadvantage of wire EDM is that it is only compatible with conductive materials. The cutting surface of certain materials may form an oxide layer. Therefore, additional precision machining is required, which increases the cost. Many industries use wire cutting machines for electrical discharge, from prototyping to completing production operations. Here are some industries: