Wire Edm Cutting: A Complete Guide

Started in 1770, EDM expands as electrical discharge machining. It uses electrical discharges for different purposes. It removes material from a sample or workpiece, sparks, or even cuts the metal. Here is an article telling you everything about wire EDM. Scroll down to learn about its benefits, applications, characteristics, and components. You will also learn how Computer Numerical Control, or CNC, stimulates the EDM process.

 

First, What is Wire EDM

 

Wire EDM is a subtractive manufacturing technique that works without direct contact. It uses a fine, electrically charged wire to process electricity-conducting metals. Filled with dielectric fluid, the thin wire acts as an electrode. It precisely cuts the workpiece by melting or vaporizing the material. The spark of the electrode erodes the metal with minimal distortion. The machining, thus, produces small yet accurate cut lines and shapes. The functionality of the EDM makes it suitable for various industries. You can find wire EDM in industries like aerospace, medical devices, die and tool making.

 

History and Origin of EDM

 

Let’s quickly understand the history and origin of EDM. How did it start, and who was the vision behind it? The concept of EDM traces its origin from 1943 by B. R. Lazarenko and N. I. Lazarenko. The Soviet scientists discovered a method to replace tool wear with electrical discharges. On a commercial scale, wire EDM was first introduced in the 1960s. However, it was in the 1970s that the integration of CNC technology revolutionized wire-cut EDMs. It improved precision and efficiency in the EDM cutter. In simple words, CNC with EDM wire cutting eases complex and detailed machining tasks.

 

What Makes EDM Different From Wire Cut EDM

 

Wire-cut EDM is different from traditional EDM in several ways. First, EDM uses solid electrodes, while wire EDM relies on thin wire for cutting and profiling. 

• Wire EDM is faster and more effective than traditional ones. All thanks to its ready-to-use heated wire electrode.
• In general, traditional EDMs are used for roughing. On the other hand, wire-cut EDM is useful for final and finished operations.
• Wire cutting is best for 2D cutting, while traditional EDM works well for 3D profiles as well.
• With its accuracy, wirecuts can produce complex and precise results compared to others.

 

Understanding the Components of Wire EDM Machine

 

Let’s come to the next section discussing the important components of wire EDM. An EDM wire-cutting machine comprises different parts that work together for results. Here is the list of components of the machine along with its functions:

 

Power Supply

 

The first component is a power supply that delivers charge to the machine. It defines the properties of the electrical charges generated between the electrodes. We advise you to use a reliable, high-quality power supply unit.

 

CNC Tools

 

The Computer Numerical Control tools control the functioning of wire-cutting EDM. It guards the procedure related to sequencing and cutting of wire paths. The accuracy of CNC machining defines the sophistication of the machine and its error level.

 

Wire

 

The wire is the primary component of the machine, and it serves as an electrode. Thus, in simple terms, it generates electrical discharge to support the process. The shape and dimensions of the wire influence its functionality. Here are the characteristics you must consider to choose the right wire:

 

• purpose of your project
• conductivity and tensile strength
• vaporization temperature
• tensile strength and hardness

 

In general, the diameter ranges from 0.05 to 0.25mm. Here are the types of wires used in CNC Wire EDM:

 

Brass Wires

 

Brass is the most common wire used in EDM. It is popular for its excellent electric-flow properties. The composition of the material, made up of copper and zinc, plays an important role. The zinc content guards the machine’s performance. However, the composition of zinc should still be under 40% to balance the corrosion rate.

 

Zinc Coated Wires

 

Another wire material is zinc-coated. It is obtained by applying pure zinc or a zinc oxide layer on the wire. Such wire enhances the functionality and speed of the EDM cut wire machine.

 

Diffusion-annealed Wires

 

These refer to the wires coated with over 40% pure zinc. The excess zinc composition makes the wire ideal for mass production and industries.

 

Electrodes

 

The wires used in the system act as electrodes for the machine. These electrodes are generally divided into two types: cathode and anode.

 

Servo Motor

 

The servo motor acts as a barrier between the two electrodes and ensures that they don’t come in contact. It protects against any mishaps or failures during the EDM cutting process.

 

Dielectric Medium

 

In the end, a dielectric fluid fills the EDM system. The fluid prevents the tiny particles of the anode from getting attached to the cathode. In general, the most popular dielectric medium is deionized water. It cools the surface and gives it a smooth finish.

 

How EDM (Electrical Discharge Machining) Works

 

Now comes the major question of how electrical wire discharge machining works. The wire-cut EDM process operates on a simple technique. There are two sides of wire or electrode, one carrying charge and the other carrying conductive material. When the two electrodes come in contact, they create an electrical discharge. The spark generated indicates the flow of electricity. The electric spark is capable of producing intense heat ranging from 8000 to 12000 degrees Celsius. The temperature can easily melt or vaporize almost every conductive material.

 

Further, these discharges take place frequently with a small time gap. An adaptive machine controls the discharge gap in the electrode, maintaining consistency. That’s how the material or workpiece is cut in the desired shape. But do you know what’s the best part? An EDM also flushes away tiny particles. Thus, it keeps the machine clean, removing all the best products.

 

General Applications of Wire Electrical Discharge Machining

 

As mentioned above, wire EDM is useful for different industries. It helps reduce the overall costs and speeds up the entire process. Here are the general applications of the wire-cut EDM:

 

Automotive Industry

Manufacturers in the automotive industry need metal parts for different machines and vehicles. With wire EDM machining, these businesses need not rely on mechanical forces. The process customizes the metal workpiece for parts like bumpers, car doors, dashboards, etc.

 

Aerospace industry

 

Similar to automotive, the aerospace sector also uses wire EDM to manufacture detailed parts. It turns into a savior for the parts that can’t withstand the high temperature and stress. Further, the accuracy and stability of the machine result in an excellent surface finish. The common resultant products include aircraft engines, turbine blades, and other parts.

 

Medical Industry

 

With high levels of accuracy, EDM machines produce complex medical parts. It is used in sensitive fields of medical sciences, including optometry and dentistry. It can easily manufacture dental implants and syringes without compromising quality.

 

What are the Metal Materials a Wire EDM Machine Can Cut

 

Now, you might be working on the common electricity-conducting metals that can work with a wire EDM machine. Wire-cut EDM machines can process with different types of materials. It can help in creating even the complicated shapes and patterns on the workpiece metal. You might be amazed to hear that these machines can work even with tough and delicate materials. Here is the list of workpieces that you can use with the wire EDM machine:

 

Titanium

 

The wire EDM cutting machine can work with titanium. It efficiently handles the alloy’s stickiness and prevents the formation of long chips. Plus, the machine’s deionized water keeps the waste heat generation under control.

 

Aluminum

 

Because of its soft and smooth characteristics, aluminum is quite challenging to cut. Further, cutting aluminum also results in gummy build-up. However, the EDM wire-cut machine solves every related issue related to machining.

 

Steel

 

Steel is popular for its strength. It produces a bulk amount of heat while cutting. Sometimes, it can be hard to balance the heat produced in the process. However, a CNC EDM machine overcomes every related concern.

 

Brass

 

Because of its high tensile strength, brass adapts to a wire-cut EDM machine. However, the process is a bit slower because of the smooth metal surface.

 

Graphite

 

Because of its characteristics, graphite is quite difficult to cut. The wire EDM services ease the process, preventing particle pull-out.

 

Understanding the Advantages and Limitations of Wire EDM

 

Let’s understand the advantages and limitations of wire EDM:

 

Advantages

• More precise and accurate cuts and pattern shaping.
• Eliminate the processing and finishing of workpiece metal.
• It can even create suitable complex designs and shapes.
• Overcome the challenges of traditional CNC machining.
• Ideal for fragile and sensitive materials that can’t withstand the traditional machining stress.
• Leave no burrs, failure, or distortion of material.
• Work in detail, resulting in tiny parts.
• Can work without interruptions.

 

Disadvantages

There are certain limitations associated with the application of wire-cut EDM:

• Work only with the conductive workpiece.
• Often, it needs additional finishing, which can be expensive.
• High initial investment cost.
• Require regular maintenance.

 

Role of CNC in Wire EDM Machines

 

CNC uses pre-programmed software to automate the machines and their processes. CNC in wire EDM machines controls the wire path and machining process. Here is the contribution of CNC in EDMs:

• Using stepper motors, CNC results in high accuracy and tight tolerances.
• With numerical control, CNC wire EDM automates the cutting process.
• It also minimizes material waste by producing repeatable results.
• Improve time efficiency and reduce labor costs.
• Apart from that, CNC Wire EDMs produce superior surface finishes in less machining time.

 

Way Forward

There’s no doubt that wire EDM is a versatile yet accurate process. It can create complex shapes within less time and resources. At Aixi Hardware, we utilize our deep understanding of the CNC mechanism to enhance wire EDM tolerances and capabilities. Our simple process can create high-precision cuts for all kinds of conductive materials. Contact us for further queries, and we will find the right EDM solution for you.

 

Frequently Asked Questions

 

Is wire-cut EDM expensive?

Wire-cut EDM may have high installation costs. However, you need to worry about the cost. The precision and versatility of wire-cut EDM help save time and labor, thus reducing costs in the long run.

 

Why is it necessary to add deionized water to the EDM?

Deionized water is known for its low carbon count. It serves as an important medium in wire EDM as it balances the dielectric temperature.

 

What is sinker EDM?

Sinker EDM is a type of EDM machining. The process uses an electricity-conducting metal that results in the desired shape at the end.

 

What is hole drilling EDM?

Unlike wire EDM, hole-drilling EDM machines use electrical charges to drill tiny holes.

 

Is wire EDM the same as laser cutting?

Both laser cutting and EDM help to cut the workpiece, but there’s a little difference. Wire EDM uses electrical erosion, and lasers use a high-powered thermal beam.