Electrical Discharge Machining

Using thermal energy to create high-quality, accurate parts that fulfill your manufacturing needs.

Premium parts offer high-quality electrical discharge machining services suited for our wide range of clients from different industries. Our Electrical Discharge Machining (EDM) technique provides results with high accuracy and close tolerances, ensuring that your product parts meet the requirements and operate as intended. The entire EDM process is supervised by our experienced specialists and optimized to work with any conductive material. Its core capabilities also involve producing product elements with a smooth surface finish without additional requirements. We carry a wide range of conductive materials, allowing you to choose the one that will improve the functionality and performance of your part in its intended application. We commit to delivering the best solution for your production needs, providing quality components within your proposed timeline.

What is Electrical Discharge Machining?

Electrical discharge machining, or EDM, is a heat-based subtractive process that uses thermal energy instead of mechanical machining to melt or vaporize extra material from a workpiece. This method manipulates erosion to cut and shape the raw materials as required. Due to using an electrical discharge, this process is also known as spark machining, utilizing an electrical spark between 8000º C to 12000º C. EDM is similar to laser cutting. It is regarded as a non-traditional method compared to other manufacturing techniques, including cutting tools. Due to its effectiveness, this process aids molding and tooling, particularly for hard materials like titanium or extremely complicated geometries that are challenging to mill.

Electrical discharge machining only performs with material with good conductors as it depends on electricity conduction through the material. As long as the material has good electrical conductivity, the procedure will deliver reliable results in producing high-accuracy cuts regardless of the material's hardness or softness.

Engineers may often resort to EDM to create desired cuts, sharp internal edges, or deep cavities when CNC milling and CNC turning processes may fail.

How does Electrical Discharge Machining work?

The electrode and the workpiece are the two primary elements of the procedure, with one end of the power supply linked to each. The workpiece conducts the opposite side of the charge while the electrode carries the other side.

As the electrode moves closer to the workpiece, it causes a white-hot electrical spark that leaps in between until it reaches the breakdown volume. This leads to a temperature rise in the spark gap between 8,000 and 12,000 degrees Celsius, causing the material to melt and erode. Using an insulating or dielectric fluid at such high temperatures is necessary. The workpiece and electrode are submerged throughout the procedure in the dielectric fluid.

The dielectric fluid controls the electric spark. It also functions as a process coolant and flushes out the micro-particles that erode. The eroded particles can be as small as 2 microns. For comparison, the thickness of human hair is 70 microns (+/- 20 microns). The eroded particles are similar to dust and smoke particles in size. Hence, EDM allows us to produce parts with great accuracy.

It's essential to remember that the entire process is automated and controlled thru CNC with zero human intervention.

Types of Electrical Discharge Machining

The EDM procedure is distinctive yet conventional. However, there are many techniques for handling this procedure. EDM is divided into three categories which help ensure that there are other alternatives in case one method does not work. Different types of electrical discharge machining include the following:

Die sinking

Die-sinking EDM is the most efficient method to create parts with complex cavities and is also known as Ram, sinker, volume, traditional, or cavity-type EDM. Additionally, it fixes sharp interior corners during CNC milling. This technique uses a dielectric fluid, graphite, or copper electrodes, and an electric spark is generated between the electrode and the workpiece. In the first step, an electrode is produced in the opposite shape of the required cavity, which creates the die. While immersed in a dielectric fluid like oil, a voltage is generated between the electrically conductive workpiece and the die.

As soon as an electric breakdown occurs, a spark leaps the spark gap and the die is gently lowered toward the workpiece. This step melts and vaporizes the material from the workpiece, and the dielectric fluid removes any ejected particles. During this process, a small portion of the electrode is also often eroded. As the series of high-frequency sparks consistently remove small amounts of material from the work piece, it will form the desired shape and cut out accurately. Precision machining is used to carefully regulate every aspect of this procedure, including the servers, power supply, and electrode positioning.

Wire EDM

Wire EDM is a standard procedure known as wire erosion or spark EDM and is commonly used to make extrusion dies. A brass or copper wire slices the workpiece. Here, the electrode is a thin wire (with a diameter of around 0.05 mm to 0.35mm) and the deionized water usually serves as the dielectric fluid. The process involves constantly unfolding the wire from an automated feed using a spool. It also builds the possibility of the workpiece and wire compromising the electrical discharge. Therefore, the cut needs a new discharge path. This strategy is adequate, but engineers should be aware that the wire must go through the workpiece. Hence, it effectively creates two-dimensional cuts into three-dimensional pieces.

This method can produce intricate features (such as razor-sharp internal corners) that are not attainable with CNC machining services.

Hole EDM

As the name suggests, Hole drilling EDM is an excellent application for fast hole drilling. With the use of tubular electrodes, hole-drilling EDM creates tiny, deep cavities in a variety of relevant materials. Compared to traditional methods, hole EDM does not require deburring. The operation has some basic concepts of die-sinking EDM, except the cut is made using a pulsating cylindrical electrode that moves deeper into the workpiece. In contrast, the electrode supplies the dielectric fluid to the machining area.

Hole-drilling EDM is applicable in specific situations, such as when a product needs intricate cavities. This technique has been essential for developing high-temperature turbine blades as it can produce highly complex cooling channels inside the turbine blades.

Sinker EDM

This type of Electrical Discharge Machining, also known as Ram EDM, Plunge EDM, Die sinking, or Cavity-type EDM, as it produces intricate cavity shapes for a variety of casting purposes, including plastic injection molding.

Sinker EDM machines submerge the workpiece and electrode in oil or dielectric water. The electrode is wired to a power source, creating an electrical potential between the two elements, causing a breakdown to form a plasma channel and spark jumps. The power supply frequently causes multiple sparks at once.

This EDM machine produces a "ramming" or "sinking" effect as more sparks occur, eroding the base metal as the electrode is lowered. Once the procedure is completed with all components removed, the base metal is oxidized in a particular form or pattern, similar to an engraving.

Types of EDM applications

Electric discharge machining is the best choice when conventional machining methods are no longer effective at removing material from electrically conductive materials.

Any conductive material, no matter how soft or hard, can be cut using an EDM machine. We can machine various metals with EDM since all metals conduct electricity to some extent. EDM uses bronze, tungsten, copper, steel (carbon, high alloy, stainless, and hardened steel), Inconel, titanium, and other materials.

Our EDM services are employed by various industries, from aerospace to automobile. It has long been used for dental parts but is now finding more significant usage in producing surgical, implant, and prosthetic tools. Electrical discharge machining is best suited to produce tools and features such as rotary forms, injection molding tools, extrusion dies, straight or small curved holes, sharp internal corners and engravings on hard materials. Here are some of the applications where EDM is widely preferred to create precise and unique parts:

Small hole drilling

Regardless of the material's hardness, electrical discharge machining is a quick and distinctive approach to produce accurate deep minor hole drilling. A brass electrode tube directs electrical discharges onto the material during the hole-drilling procedure, making it easier to make holes of different sizes. Its ability to create holes on incline surfaces and other challenging locations makes it intriguing.

Injection Molding

EDM is often required to produce molds with the proper dimension, depth, and shape. It is the primary method of injection molding that mold producers use. The most frequent kind, in this instance, is wire EDM which is typically the ideal technique to use as injection molding calls for various sensitive and intricate workpieces. Additionally, it frequently results in a clear and fine EDM surface finish.

Die Casting

Die-making applications certainly benefit from EDM as well. Extreme accuracy is necessary when producing highly customized dies. These dies have sophisticated details, including deep ribs, sharp internal edges, and other features. Additionally, tough steel alloys are often used to make dies. These alloys are usually more difficult to process using conventional techniques. Before heat treatment, the hard steel alloys need finishing, which can compromise the precision of the details. To avoid this mishap, it is more suited to use the EDM process.

Advantages of using EDM

More design flexibility

EDM allows cutting complex shapes and depths, which are impossible to achieve through traditional methods. Its high tool lengths and diameter ratios make it an efficient deep processing technique, making it easier to cut deep ribs, small holes, and sharp internal corners without creating a burr.

Greater precision

EDM is one of the highest-accuracy production techniques available today. The accuracy of a standard setup is up to 0.025 mm, but there are specialized EDM machines that can reach 0.005 mm. A part's precision is determined by various elements, including the material's properties, the machining process, and the required level of surface finish.

Better surface finish

Traditional material removal techniques, like CNC milling, produce machining markings on the workpiece that must be removed through post-machining finishing. EDM makes surfaces with zero-directionality, allowing for uniformly smooth surfaces without needing extra processing. However, rapid EDM processing can leave a lightly bead-blasted texture behind.

Error-free machining

In this procedure, the tool must make direct contact with the workpiece. No distortion occurs when no forces are acting on the part. This makes it possible to create extremely fine features without the risk of them breaking. As there is no distortion, it is possible to obtain tolerances as tight as +/- 0.012mm.

Works on hard material

A key feature of electric discharge machining is its ability to cut through any material, provided it is conductive. As a result, complex materials like Inconel and tungsten carbide can be machined effectively.

Electrical Discharge Machining is a preferred choice for high-demand machining applications. When parts need to meet strict geometrical specifications, electrical discharge machining is a great technique in conjunction with a conventional machining method like CNC. EDM has made it possible for industries including aerospace, automotive, and medical device to create complex yet highly precise tools and instruments. In addition, EDM can be used to machine components that are difficult to machine using other methods, such as those made from hard, brittle, or heat-sensitive materials.

At Premium Parts, our EDM process offers an excellent solution to all your manufacturing requirements. This machining process enables us to produce components in various geometries per customer requirements. The high-precision cutting technique is effective with any conductive material. No matter what product elements you require or applications you have, we can assist you entirely, from the beginning to the final stage. Overall, our EDM service has been a valuable technique for many of our clients, helping them produce parts more efficiently and accurately.

Why choose Premium Parts

Strong competency

Our operations follow a consistent process that minimizes risk, an inspection of raw materials before manufacturing and the ability to produce high-quality parts uniformly.

No limit on the quantity required

EDM services at Premium Parts are accessible to all customers without limitations or minimum order quantities. From one-piece to mass volumes, we can produce components in different amounts as per our client's requirements.

Experienced internal technicians

Our expert technicians and operators are adequately trained to work with various materials and EDM applications following international quality standards. Constant monitoring and quality control enable us to deliver precise pa to our clients.

Prompt delivery

Our efficient quality control, supply chain, and delivery logistics make it possible to deliver your products in the least amount of time. Lead times for smaller items could be shorter.

FAQs

When should Electrical Discharge Machining be used?

Electrical machining can be used for the following purposes:

Cutting rotary forms
Drilling curved holes
Engraving on hard materials
Removing faulty tools from workpieces
Drilling small holes
Cutting sharp internal corners
Making injection molding tools
Cutting extrusions
Removing broken devices from workpieces

What type of surface finish is possible using EDM?

The cutting speed and surface finish quality are balanced, like any other machining method. It is typical for the first cut to be faster and rougher, followed by slower cuts that provide a cleaner surface finish. More tool passes can be made at slower speeds to get a smooth surface polish, which can increase the machining process and costs.

How accurate is EDM?

EDM has a very tight tolerance range of +/- 0.012mm, which is why it is highly preferred in the aerospace and medical industries.

What materials are suitable for EDM machining?

Electrical discharge machining is generally capable of processing any conductive materials. Some materials, including aerospace-grade high-nickel alloys, can be difficult to machine. However, the solution is frequently altering the electrode material or machining speed. The electrode’s conductivity and erosion resistance are the key factors that influence electrode material selection.

Electrical Discharge Machining