Validation of electrical discharge machining electrodes made with rapid tooling technologies

Abstract

Rapid tooling technologies allow tools and moulds to be manufactured in a short time and with complex geometry. The main aim of this research is to develop new electrical discharge machining (EDM) electrode testing and manufacturing by applying rapid prototyping (RP) and electroforming technologies. Copper electroformed shells allow complex electrodes to be obtained with a high dimensional precision and with the required texture according to the RP model. The main novelties of this work are the following: - A new copper electroformed shell testing methodology starting from plastic prototypes has been formulated. The composition, electrolytic bath additives, metallic structure of shells, internal stresses, hardness, pitting, dimensional precision and roughness relating to the model have been analysed. - A new tool for copper shells subjected to the EDM machine has been designed. Standardization of these tools is very important for their industrial viability and it is possible to assemble different shells in the same standard tool in a few seconds. - Different manufactured electrodes have been tested in an EDM machine and compared with conventional electrolytic copper electrodes. Results have shown good behaviour relative to conventional electrodes. Lower weight and better refrigeration conditions are also an advantage.