Electrical Discharge Machining

Rapid Water Jet Design
Electrical Discharge Machining

RWD excels in creating extremely precise parts that can fit together perfectly. Most Engineers use EDM if they need to work with metals like high-strength titanium or hardened steel that are difficult to machine using traditional CNC machining. EDM is also particularly effective for hole-drilling applications. 

What is it and how does it work?

Electrical Discharge Machining (EDM) is a subtractive manufacturing process in which metal is removed from a source material by what is called “electric spark erosion.” An electric spark is used as a cutting tool, and pulsed at a high frequency through the electrode into the workpiece to produce the desired shape of the finished product.

For EDM to work, both the workpiece material and the electrode must be conductors of electricity. It works much the same way as an electrical short that burns a small hole in the piece of metal it touches, but in a highly controlled and directed way.
The process can be performed in 2 different ways:

  • The first involves an electrode (tool) constructed like a mold in the desired shape of your final product that is then lowered onto your chosen material to burn away the excess metal.
  • The second uses a thin electrode approximately the diameter of a needle which is controlled by advanced computer programming to cut the desired shape.

Benefits of
Electrical Discharge Machining

EDM machines can be programmed for vertical machining, orbital, vectorial, directional, helical, conical, rotational, spin and indexing machining cycles. This versatility gives Electrical Discharge Machines many advantages over conventional machine tools, as does the versatility in materials it can work with which include anything that is electrically conductive.

It’s also incredibly effective for creating intricate forms and parts, as X, Y, and Z axis movements allow for the programming of complex profiles using simple electrodes. Complex dies sections and molds can be produced accurately, faster, and at lower costs. The EDM process is also burr-free, and hardened workpieces can be machined eliminating the deformation caused by heat treatment. With its focus and precision, thin fragile sections such as webs or fins can be easily machined without deforming the part.

Pros

EDM creates complex shapes in challenging materials suitable for precision mechanical components. With no direct contact between the tool and piece, it can cut even miniscule parts without breakage, distortion, or burrs.

Cons

EDM has a slow rate of material removal, takes time and money to create electrodes for Ram/Sink EDM, and may have trouble with sharp corners due to electrode wear.

Applications

01

Electronics

02

Tool and Die

03

Automotive