Abstract
Abstract Ceramic materials possess excellent properties like high hardness, superior corrosion resistance and great resistance to wear. These materials are low in density and demonstrate high strength to wear ratio. There is an increasing need to machine these hard and brittle materials as they have various engineering applications. The distinguishing properties of ceramics do not allow them to be machined by conventional processes. Electrical discharge machining (EDM) is a non-conventional process and a viable option to machine and generate complex shapes in hard materials. EDM can be used on materials irrespective of its hardness and wear resistance as it is a non-contact machining process and no active force is applied between the workpiece and electrode during machining. As EDM requires the workpiece to be electrically conductive, machining ceramics by this process is a challenge. Alterations need to be carried out in order for insulating ceramics to be machined by this process. This paper discusses the basics of EDM process and its control parameters. A classification of ceramic materials based on their electrical conductivity is established and their relevance to the respective material removal mechanisms have been identified. Different approaches to successfully machine ceramics by EDM have been reviewed. The challenges and modifications of each method have been discussed. An outline and expectations for machining a particular ceramic material and its composites have been generated. Finally, the prospects of future research in this area have been identified.