Wire EDM, also known as wire cutting, uses continuously moving thin metal wires (also known as electrode wires) as electrodes to perform pulse spark discharge on the workpiece to remove metal and cut it into shape. Sinker EDM refers to the method of machining the workpiece in a certain medium through the electro-erosion effect of the pulse discharge between the tool electrode and the workpiece electrode.

What are the characteristics of Wire EDM?

Cnc wire edm

1. No need to manufacture electrodes separately. Since the wire-shaped electrode wire is directly used as the electrode, there is no need to specially make the electrode, which can save the design and manufacturing cost of the electrode.

2. It can process workpieces with complex shapes that are difficult to process by traditional cutting methods. It is only necessary to compile different control programs for different workpieces, and it is easy to realize automatic processing for workpieces of different shapes. It is very suitable for the processing of small batch parts, single pieces, and trial products with complex shapes.

Because the electrode wire is relatively thin, it can easily process micro-shaped holes, narrow slits, columns, and holes with complex cross-sections. Due to the narrow kerf, the actual metal removal is very small and the material utilization rate is high.

3. Using the principle of electro-erosion machining, the electrode wire is not in direct contact with the workpiece. The force between the two is very small, so the electrode wire and the fixture do not need too high a strength. In traditional turning, milling, and drilling, the hardness of the tool must be greater than that of the workpiece, while the wire electrode material of the CNC wire EDM machine does not have to be harder than the workpiece material.

Wire edm machine
Wire edm machine

4. Directly use electric energy and thermal energy for processing, which is convenient to adjust the processing parameters that affect the processing accuracy, such as pulse width, interval, servo speed, etc. It is beneficial to improve the machining accuracy and the automatic control of the machining process.

5. The working fluid is generally water-based emulsion or pure water, which is low in cost and will not cause a fire.

6. Electrode wear does not need to be considered. In the wire cutting process, the electrode wire always moves at a certain speed, and the electro corrosion products are taken away together with the circulating working fluid. Moreover, the loss of the electrode wire itself is very small, and its loss can be ignored in actual work. Therefore, there is no influence on workpiece accuracy due to electrode wear. Especially in the process of slow-moving wire cutting, the wire electrode is one-time use, and the loss of the wire electrode has less influence on the machining accuracy.

What are the characteristics of Sinker EDM?

Sinker EDM is that when the tool electrode and the part are close to each other, the inter-electrode voltage will ionize the dielectric between the positive and negative electrodes to form a spark discharge and generate a large amount of thermal energy in an instant. Then the metal is partially melted or even vaporized, and the metal is corroded, thereby forming the required type holes and blind holes.

  • Sinker EDM can process various materials with high hardness, high melting point, high strength, and high toughness. No hard, brittle metal material can resist this high temperature, as long as it can conduct electricity, it can be processed.
  • The energy density of pulse discharge is high, which is convenient for processing special materials and workpieces with complex shapes that are difficult or impossible to process with ordinary machining methods. Not affected by material hardness, not affected by heat treatment conditions. During sinker EDM, because the metal is not removed by the mechanical method of the tool, there is no mechanical force during processing, so it can be used to process small holes, narrow grooves, and various complex shapes of holes and cavities.
  • The duration of pulse discharge is extremely short, the heat conduction and diffusion range generated during discharge are small, and the range of material affected by heat is small.
  • The tool electrode is easy to manufacture. During machining, the tool electrode is not in contact with the workpiece material, and the macroscopic force between the two is extremely small. The tool electrode material need not be harder than the workpiece material.
Electrode copper
  • Since the electric pulse parameters can be adjusted arbitrarily, rough, medium, finishing, and continuous machining of parts can be performed on the same machine tool, which saves equipment and improves efficiency.
  • Sinker EDM is directly processed with electric energy, which is convenient to realize automation in production.

What is the difference between Wire EDM and Sinker EDM?

1. Wire EDM does not need to manufacture electrodes separately. The sinker EDM process, on the other hand, must precisely manufacture the electrodes. Electrodes used in wire EDM are finished metal wires (such as tungsten wire, molybdenum wire, and brass wire) and do not need to be specially manufactured.

2. Electrode loss needs to be considered in sinker EDM processing. Electrode wear is inevitable in sinker EDM, and the machining accuracy is also affected by electrode wear. Electrode wear may not be considered for wire EDM. In wire EDM, the electrode wire always moves at a certain speed, which not only takes away the electro corrosion products together with the circulating working fluid but also has very little loss of its own. Its loss is negligible in practical work.

3. Wire EDM cannot process blind holes, but only through holes or shapes of parts. Sinker EDM can process through holes and blind holes and is suitable for processing cavities of plastic molds and other parts with complex shapes, as well as engraved characters and patterns.

JTR can provide a variety of CNC machining services including wire EDM. Through the above, you have already understood the characteristics of the EDM process. If you need wire EDM service, please contact us, JTR professional staff will provide you with professional service.

Related Articles