7. Summary

Electrical discharge machining (EDM) is a process that removes material by fusion, vaporization and erosion, and is reserved for conductive and semi-conductive materials. It is insensitive to the mechanical characteristics of the materials to be machined. However, its effectiveness depends on the thermal diffusivity of the material. It can therefore be used to machine metals and alloys, hardened steels, refractory metal alloys, metal carbides, certain ceramics and polycrystalline diamond.

After machining, the material presents a thermally-affected layer: structural modifications, presence of residual stresses and microcracks. Resistance to wear and corrosion is increased, while fatigue strength is significantly reduced.

In ripping, the process is characterized by :

• material flow rate (from...