Development and application of new composite materials as EDM electrodes manufactured via selective laser sintering

Abstract

The cost of a part manufactured by electrical dischargeEDM machining (EDM) is mainly determined by electrode cost. The production of electrodes by conventional machining processes is complex, time consuming, and can account for over 50 % of the total EDM process costs. The emerging additive manufacturing (AM) technologies provide the possibility of direct fabrication of EDM electrodes. Selective laser sintering (SLS) is an alternative AM technique because it has the possibility to directly produce functional components, reducing the tool-room lead time and total EDM costs. The main difficulty of manufacturing an EDM electrode using SLS is the selection of an appropriate material, once both processes require different material properties. The current work focused on the investigation of appropriate materials that fulfill EDM and SLS process demands. Three new metal-matrix materials composed of Mo–CuNi, TiB₂–CuNi, and ZrB₂–CuNi were developed and characterized. Electrodes under adequate SLS conditions were manufactured through a systematic methodology. EDM experiments using different discharge energies were carried out, and the performance evaluated in terms of material removal rate and volumetric relative wear. The results showed that the powder systems composed of Mo–CuNi, TiB₂–CuNi, and ZrB₂–CuNi revealed to be successfully processed by SLS, and the EDM experiments demonstrated that the new composite electrodes are promising materials. The work also suggests important topics for future research work on this field.