Methodology for developing technological tables used in EDM processes of conductive ceramics

In the electrical discharge machining (EDM) process of ceramic materials, the adequate selection of process parameters is an especially important factor to take into account. These conditions will determine technological properties, such as surface roughness, material removal rate (MRR) and electrode wear (EW). By means of the technique of design of experiments (DOE), as well as techniques of multiple linear regression, it is possible to obtain technological tables that will allow the programming of the numerical control units used by the EDM machine tools. This is done by employing two different machining strategies in order to achieve a specific surface quality on the parts: one that minimises the electrode wear and the other that maximises the material removal rate, that is to say, the process speed. This has a great deal of interest from a technological point of view as, at present, these types of tables do not exist in the case of ceramic materials, because of the very recent application of the EDM technology to this group of materials.