EDM wire cutting Extrusion

What is Electric Discharge Machining?

Electric Discharge Machining (EDM) is a machining process that uses electrical sparks to cut through metal material by melting or vaporizing it. This cutting process is achieved by using electrical discharges between two electrodes which are separated by a dielectric liquid and subject to a varying amount of electrical voltage. Wire electrical discharge is a form of machining that is used for creating intricate and precise shapes and contours in parts that may have otherwise been unobtainable from more traditional CNC machining methods. One of the advantages is that EDM is used for machining parts made of materials that are usually difficult to machine with precision and quality control using standard methods, such as heat-treated steels, alloys, and special metals. The EDM process is capable of producing complex shapes with very tight tolerances. It can also machine narrow slots and small holes accurately, making it an invaluable tool for manufacturers and other engineering applications and industries.

Types of EDM

There are three types of EDM cutting processes. These include:

Die sinking EDM– The die sinking EDM process is the conventional electric discharge machining process. Die sinking EDM uses a die to create complex features. Die sinking EDM involves the use of a die, which is an electrode made out of copper or graphite and is used to shape the metal. An electric current is passed through the die to erode the metal away in a controlled manner. The die is then gradually moved in order to create the desired shape while the material excess is flushed away in the dielectric fluid. This process is particularly useful for machining complex shapes that are difficult to create using conventional machining techniques and other EDM methods.
Wire cut EDM– Something like a wire cutting through cheese, the wire EDM machining process relies on a thin wire that cuts through metal via spark erosion. Wire EDM works by using a thin wire to create sparks between the wire and the material being cut. The sparks erode the material and create a precise cut. This process can be used to cut complex shapes and intricate patterns. In many cases wire EDM is faster and more accurate than traditional machining methods, making it cost-effective for certain shapes. When two axis of motion are involved it results in parts with vertical edges and two-dimensional shapes. EDM wire cutting machines are capable of creating complex shapes with incredibly tight tolerances. Materials that can be cut by wire EDM include all conductive metals such as titanium, steel, aluminum, and brass.
Hole drilling EDM– Hole drilling EDM is a machining process that uses electrical discharges to create holes in metals. The process is similar to conventional drilling, but instead of using a drill bit, an electrode is used to create sparks between the workpiece and electrode. The spark discharges melt or vaporize tiny amounts of the workpiece, which can then be further machined to the required size and shape. Hole drilling EDM is an extremely accurate and precise method of machining and can be used to create holes in very hard materials. Hole drilling EDM can create small and deep cavities in materials.

EDM Machining Service – Custom Parts

EDM machining equipment and cutting techniques can handle high volumes of steel, aluminum, and other metals with utmost accuracy. EDM machine shops provide EDM services including wire EDM, Die sinking EDM and hole drilling EDM.They make custom parts and metal components. Designing custom parts for EDM is a process that requires precision and accuracy. By utilizing EDM technology, engineers can create complex shapes and features that are not possible with traditional machining methods. EDM allows engineers to create parts that meet exact customer specifications and requirements, while also ensuring a high level of accuracy and quality, making the method an essential tool for engineers and manufacturers who are looking to create precision parts that meet their customer’s needs.

Advantages of Wire EDM

Wire EDM offers some distinct advantages to other processes such as CNC milling. Some of those advantages include:

It is possible to machine sharp inside corners and other features that are difficult to machine on a CNC mill
Extremely high tolerances can be achieved
Tolerances are achievable down to a ten thousandth and surface finishes of 4 Ra(μin)
Wire EDM can use up to five axes, allowing for complex shapes and tapered parts
There are virtually no machining forces making it effective for thin featured parts
Narrow features can be cut in thick material
Precise cuts are very repeatable
Cuts can be made that are just micrometers thick
Can machine materials that are very hard such as carbides and graphite
Can create holes as small as .015” in diameter
Can cut multiple 2D parts at once if they are able to be stacked during machining
Some machines allow for feed speeds up to 7 inches per minute depending on wire and workpiece material and thickness
Does not leave tool marks or burrs
Can cut materials up to 12 inches thick

Limitations of Wire EDM

Wire EDM is a very versatile process that has some traits that make it able to create parts with complex geometries with ease that are difficult to impossible by other machining operations. It also has some limitations that must be taken into consideration when determining if it is the right process for your parts. Some of these limitations include:

1. It has a much slower material removal rate than CNC milling

2. Only conductive materials are eligible for machining with wire EDM

3. Slow machining and expensive consumables can make for high machining costs

4. Tight tolerances and fine surface finishes require slow repeat passes increasing machining time

5. The wire is no longer usable after one use so the wire needs constant replenishing
6. Wire EDM cannot be used for blind features and cavities, the wire must pass all the way through the part to the bottom wire guide
7. Deionized water is required for machining
8. Deionized water needs to have a system that can filter and deionize the water as the machine is cutting
9. Due to the high heat generated by the sparks, there can be a small heat affected zone and a recast layer left on the machined surface

10. Secondary processing may be required to remove the recast layer

EDM Machining Services in Manufacturing

CNC EDM is a powerful tool used by engineers and manufacturers to create precision parts with accuracy, quality, and a superior finish. This process uses dielectric fluid to erode metal with electrical sparks, allowing for greater control and accuracy than traditional machining methods. CNC EDM works quickly and efficiently, and can be used to create complex shapes and features in parts for a variety of different industries. CNC EDM is available in a range of power and speed settings, allowing manufacturers to customize their design to suit their specific needs and requirements. By utilizing this technology as a tool, manufacturers can reduce the time and effort required to create high-quality parts, allowing them to focus on other areas of the engineering process.