Electron Discharge Machining

 EDM is a special processing technique that uses electric sparks to erode the metals to work.

Thanks to its characteristics, EDM allows you to:

 

-Work on very hard metals such as hardened steel

 

-Work on the piece creating any geometric shape, which is often impossible to achieve by using other technologies.

 

– Manage with high precision the product processing.

 

The main characteristics of EDM are:

 

-Machining of hard metals or metals hardened by thermal or chemical treatments. In fact, the hardness of the material to be worked has no influence at all as regards the speed of removal, or the energy to be used in the processing.

– Working on the piece by creating different geometric or volumetric shapes. This is possible thanks to the main feature of the EDM, which does not need a rotating tool. It is possible to obtain sharp edges, to create ribs and cavities in shapes or profiles, difficult to achieve with other technologies.

– Lower timings compared with other metal cutting technologies.

– High tool wear. Higher or lower roughness of the machined surfaces, depending on the degree of finish. This is due to the creation of micro-craters as a result of the electro-erosive action.

 

Operation:

 

Processing is carried out by approaching a tool called “electrode” to the material to be worked, which is defined as “the piece”.

When both materials are near enough, electrical sparks are generated, which erode the piece in a complementary manner to the electrode shape. The choice of the electrode material and the control of the characteristics of the electric discharges allow to obtain a lower electrode erosion than that of the piece. As the piece is eroded, the electrode advances till the completion of the processing. During the processing the electrode never comes in contact with the piece, otherwise this would create a short-circuit instead of the sparks that cause the erosion.

 

The EDM is divided into two categories, depending on their application:

 

Dip EDM: axis C machines controlled and automated with electrode changer and pallet changer. In this application, the main purpose of the processing is to work the piece giving it a complementary shape respect to the electrode.

Wire EDM: this type of electrical discharge uses a brass or copper wire, which can erode the piece once it is electrically charged and approached to the piece. In this processing, a strained conductor wire is used as an electrode to cut or profiling the piece. During machining, the wire is regularly changed, because being subjected to wear of the electric discharges and to the expansion stress, it could break and cause the suspension of the processing.

Our machines have a cutting capacity up to 400 mm in height and 35° taper. Wire diameter also 0.1 mm. Super-surface roughness up to 0.1 Ra.