Brush discharge plastics. The ability of an electrical discharge to cause an explosion in flammable atmospheres is measured by the "effective energy" of the discharge. The effective energy of brush discharges is 10-20 mJ, much larger than that of corona discharges 0.1 mJ. Therefore, brush discharges are considered an explosion hazard, while corona discharges are not. Brush discharges can occur from charged insulating plastics (for example polythene) to a conductor. Brush discharge A brush discharge is an electrical disruptive discharge similar to a corona discharge that takes place at an electrode with a high voltage applied to it, embedded in a nonconducting
Electrical discharge machining removal of material from the electrode to the presence of an electrical force on the surface of the electrode that could mechanically remove material and create the craters. This would be possible because the material on the surface has altered mechanical properties due to an increased temperature caused by the passage of electric current. The authors' simulations showed how they might explain EDM better than a thermal model (melting or evaporation), especially for small discharge energies, which are typically used in μ-EDM and in finishing operations. Given the many available models, it appears that the material removal mechanism in EDM