EDM Flashcards
(20 cards)
What is EDM?
Electric Discharge Machining is a thermal machining process that removes material using electrical discharges (sparks) between two electrodes.
Which materials can be processed using EDM?
Materials with a minimum electrical conductivity of 0.01 S/cm, including metals, alloys, conductive ceramics, and polycrystalline diamonds.
What is the dielectric fluid used for in EDM?
It isolates the electrodes, removes debris, cools the workpiece, and prevents oxidation.
What are the three main variants of EDM?
Die-sinking EDM, Wire-cut EDM (WEDM), and Fast Hole EDM.
What is Die-Sinking EDM?
A process where a shaped electrode creates cavities in the workpiece by electrical discharge erosion.
What makes Wire EDM unique?
It uses a thin wire electrode to cut through the material with high precision and is ideal for complex geometries.
What industries commonly use EDM?
Automotive, aerospace, die and mold making, and medical device manufacturing.
How accurate is Micro EDM?
It can achieve resolutions as small as 0.1 µm and drill holes as small as 10 µm with ±1-2 µm accuracy.
What are the advantages of EDM?
- Allows machining of hard materials
- Enables complex geometries
- Minimal mechanical stress
- Tight tolerances
What are the limitations of EDM?
- Slow material removal rates
- High power consumption
- Tool wear during the process
What are common electrode materials used in EDM?
- Copper
- Graphite
- Tungsten
- Their alloys
Why is graphite preferred as an electrode material in EDM?
It offers high thermal resistance, low wear rates, and can operate in a ‘zero wear’ regime.
What is the role of the flushing system in EDM?
It removes debris from the gap, cools the workpiece, and maintains stable machining conditions.
What is Electrical Discharge Grinding (EDG)?
A hybrid EDM process combining electrical discharge erosion with mechanical grinding for ultra-hard materials.
What is Mole EDM?
A specialized EDM process that machines curved paths or tunnels through a workpiece, like a mole digging.
What factors affect material removal in EDM?
- Material properties
- Energy density
- Electrode wear
- Dielectric fluid properties
How is energy converted in EDM to remove material?
Electrical energy is converted into heat, causing melting and vaporization of the material.
What is the main disadvantage of poor dielectric flushing?
It can cause unstable machining, short circuits, and defects in the workpiece.
What is Ultrasonic Aided EDM (UEDM)?
EDM enhanced by ultrasonic vibrations to improve machining rates and stability.
Why is EDM suitable for pre-hardened materials?
It eliminates the need for post-machining heat treatment, avoiding distortion and stress.
