Electro Discharge Machining (EDM) is a process, where we use the electrical energy to produce electrical waves and thermal energy to mould any alloy into a desired shape/size.
This machining method can only be used with materials that conduct electrical energy well. EDM is so powerful that it can cut through into hard steel without the need to soften it. This method is not only used to shape steel but it is compatible with other metals. Process
Two electrodes are placed adjacent to each other and using current discharged, material is removed. The two electrodes are separated with dielectic liquid. This method only works with an electric voltage. As we reduce the distance between the two electrodes, the electric intensity becomes greater than the dielectric, which allows current to flow between both the electrodes. This way material is removed from both the electrodes. Once the flow of current is stopped, conveying of new liquid is necessary, this will enable solid particles to be taken away and the protecting properties of the dielectric are reinstated. Uses
1- Coinages die making
This process can be used to create dies for jewelry production. Piercing can be done by use of pancake die by stamping process. To produce coins, the positive master can be made out of silver since the master is easily worn out and can be used once only. The negative die is then toughened and used in a drop hammer to produce stamped flats from outlined blanks of different alloys such as silver, bronze or even gold. IF we had to produce badges out of this, the method would be to further more shape to a bent surface by another die. This EDM method is used with oil based dielectric. Further polishing or hand engraving is done to give final touch to the badges, 2- Prototype production
The EDM process is used in making exemplar and production parts in the field of automobile, aerospace....