Machinability of Non-Conductive Ceramic by EDM: A Review

Abstract

Abstract AdvancedCeramics are gaining a foothold in the lightweight aerospace, electronics, and structural engineering component markets. These ceramics could be extensively used in modern industry, such as ballistic body armour, ceramic carbon fibre composite automoti ve brakes, diesel particulate filters, prosthetic limbs, piezoelectric sensors, and computer memory products, due to their higher compressive strength, resistance to abrasion, lower thermal expansion coefficient, higher density, and chemical stability. Ceramics are notori ously difficult to handle due to the increased hardness and brittleness. Low electric-conductive ceramics, on the other hand, can be machined using the EDM technique, in which plasma energy is used to accurately remove the material by continuous sparking between the surface and the electrode submerged in dielectric. It is observed that EDM can be applied to the material having electrical resistivity below 100 ?.cm. Most recently it has been observed that EDM could be applied to insulating ceramics too. An attempt has been made in this paper to critically review the machining of ceramics by the EDM process.