Manufacturers often integrate EDM manufacturing when the traditional machining manufacturing process has reached its limit. The EDM manufacturing process involves the integration of thermal energy to get rid of excess material from an object. Also, EDM manufacturing process delivers high accuracy and is suitable for any conductive material.
We will be examining how the EDM manufacturing process works, the types available, and the advantages.
What is EDM Manufacturing?
EDM simply stands for electrical discharge machining (EDM) involves the removal of a material from a workpiece by integrating thermal energy. EDM manufacturing is a non-traditional manufacturing method. It is similar to laser cutting. Also, EDM manufacturing requires no mechanical force during the removal process. Therefore, it is generally considered a non-traditional manufacturing method.
The EDM manufacturing process helps several industries in molding and tooling. Furthermore, EDM is popular as a result of its applicability particularly for hard materials or for complex shapes. Also, EDM manufacturing directs high-frequency electrical spark discharges to remove electrically conductive materials like carbide or hardened steel.
Electrical discharge machining EDM manufacturing uses electrode to disintegrate material from conductive materials. This non-traditional manufacturing approach helps engineers to achieve desired shapes with the integration of electrical discharges. Also, EDM manufacturing process is very precise and doesn’t require the use of tool on the workpiece.
A dielectric fluid helps to separate the electrodes used to remove material from a workpiece. After which a voltage passes through the dielectric fluid. Furthermore, EDM manufacturing works only for electrically conductive materials. One of these electrodes, which is the anode, changes shape to serve the exact purpose. The cathode is the other electrode. Two electrodes need to unite to achieve this.
Since EDM works well on hardened material, it is very easy to prevent possible deformation from heat treatment. Also, no cutting force is needed before the removal of the material.
Types of EDM Manufacturing
Hole drilling EDM
The hole drilling EDM manufacturing is commonly integrated to machine holes. This type of EDM can precisely machine very small and deep holes. These holes don’t need deburring. Also, hole drilling integrates similar basic rules as die-sinking EDM. The cut comprises a pulsing cylindrical electrode.
Hole drilling EDM plays a crucial role in the development of high-temperature turbine blades. This is because it enables the manufacturing of cooling channels in the turbine blades.
Wire EDM
This is also known as wire erosion. Wire EDM manufacturing is widely used to manufacturer extrusion dies. Also, it uses similar mechanism as die-sinking. However, in wire EDM, a fine electrically charged wire replaces the die. This wore act as the electrode. Wire EDM manufacturing method is similar to a cheese cutter that makes a two-dimensional cut in there dimensions.
The wire used in this type of EDM is always very thin. Also, the wire has a diameter that ranges from about 0.05mm to 0.35mm. Also, fresh wire spools throughout the machining process to prevent the use of burnt wire and deliver precise cutting. Wire EDM manufacturing produces precise cuts. However, integrating wire EDM only won’t produce square corners if you need to cut inside corners.
Die sinking EDM
Die sinking EDM is ideal for creating parts with complex cavities. Also, it is a method that provides a solution to internal corner issue when CNC machining. Furthermore, this die sinking method integrates copper electrodes or graphite and an electric spark put between the workpiece and the electrode.
In this method, the electrode is usually produced in a reverse shape of the cavity. Therefore, this creates the die. After which, the engineer induces a voltage between the electrically conductive workpiece and the die.
Benefits of EDM Manufacturing
EDM manufacturing offers a lot of benefits in the technology world. These benefits include:
Precision
Although EDM offers limited efficiency in terms of producing large-volume orders, it is suitable for manufacturing prototypes and small parts as a result of its high precision levels. For instance, EDM is usually integrated within the automotive industry. Also, this industry requires high precision levels to manufacture intricate engine components.
Greater design freedom
One of the main benefits of EDM manufacturing is that it enables the cutting of depths and shapes. This would never be possible with traditional machining methods. Also, EDM manufacturing allows undercuts and square internal corners. Also, this machining process doesn’t produce a burr.
Requires no mechanical force
The need for no mechanical force in EDM manufacturing is one of the reasons it is highly preferred among manufacturers. EDM doesn’t put mechanical force in the workpiece and as such, you don’t need to worry about generating fragile outlines.
Better surface finish
CNC milling usually leaves machining marks on a workpiece. These marks are usually removed by post-machining finishing. Also, EDM makes it possible to achieve uniformly smooth surfaces without any need for additional treatment. But, quick EDM manufacturing process can leave bead blasted-like texture behind.
Distortion-free machining
The tool in electrical discharge machining never comes in contact with the workpiece. Therefore, there is no distortion. As a result, every thin features machines without any risk of breaking. In addition, the absence of distortion means that you can achieve extremely tight tolerances.
Work on hardened material
One key feature of EDM is that it can work through any material in as much as it is conductive. Therefore, this indicates that EDM can machine tough materials like Tungsten carbide and Inconel.
Disadvantages of EDM Manufacturing
Cost of electrode
Die-sinking EDM requires a reverse custom electrode. It is quite expensive to machine the electrode at low manufacturing volumes.
Low rate of material removal
The rate of material removal is very low in EDM manufacturing process. Since this process requires more power, the increase in production time will affect overall cost. Therefore, electrical discharge machining isn’t effective for large-scale project.
EDM requires a high amount of electricity to take place. Therefore, it isn’t an environmentally-conscious way of machining. Companies are beginning to adopt measures to minimize their carbon footprints. Therefore, they are opting for other machining methods that need low amount of electricity and are as well less harmful to the environment.
Can machine only conductive materials
EDM can only machine electrically conductive materials. Although, EDM manufacturing process can be stress-free, there is a thermal process that can affect the workpiece’s metallurgy.
Applications of EDM Manufacturing
EDM manufacturing is widely used in small-volume production. Therefore, it is applicable in several processes like small hole drilling, milling, and more. Also, this process is valuable for various industries such as aerospace and automotive. EDM is ideal for use in the following applications:
Die casting
EDM is ideal for use in die-making applications. Also, the production of dies needs extreme accuracy. These dies have deep ribs, internal corners, and some intricate features. Furthermore, dies comprise hard steel alloys which are harder to machine using traditional methods.
Injection molding
EDM determines how you can get the appropriate depth, shape, and dimension of a mold. In addition, EDM is an injection molding process commonly integrated by mold manufacturers. Injection molding demands different complex and delicate workpieces. Therefore, EDM is the best machining method to integrate.
Small hole drilling
EDM is a special way to make precise deep small holes in materials irrespective of their hardness. The hole drilling involves the use of a brass electrode tube.
Equipment Used in EDM
Electrical discharge machining involves the use of different equipment like:
Power generator and control unit
Generator helps to integrate potential difference. Therefore, the voltage applied in this machining process is in pulse form. Furthermore, a control unit helps to regulate the operation during the process.
Servo system
The servo system helps to control the tool. Also, it maintains a gap between the workpiece and electrodes.
Dielectric reservoir and pump
Pump helps to circulate the dielectric between the workpiece and the tool. Deionized water serves as dielectric medium.
Tool holder
The tool holder helps to hold the tool
Frequently Asked Questions
What is EDM’s accuracy?
EDM can achieve tight tolerances of +/-0.012mm. Due to its high accuracy rate, EDM is widely used in medical and aerospace industries.
When can I use EDM?
EDM is ideal for use in drilling curved holes, cutting sharp internal corners, and cutting extrusions. Also, it is suitable for engraving on hard materials and cutting rotary forms.
What type of surface finish can EDM achieve?
Machining processes often maintain a balance between the surface finish quality and cutting speed. The initial cut is usually rougher and faster. However, the subsequent cuts are usually at a slower speed. To create an exceptional surface finish, you can make further tool passes at slower speeds. However, this increases the cost and time of machining.
Conclusion
EDM has been the solution for highly demanding machining applications. This machining process has helped engineers in applications where traditional approaches are impossible. Also, EDM helps to achieve exceptional results when combined with a traditional machining method like CNC machining. Also, the ability of EDM to machine hard materials make it ideal for machining materials such as Inconel.
