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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.

The production of electrical discharge machining (EDM) electrodes by conventional machining processes 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 reduce 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. This work investigated the direct production of EDM electrodes by means of the SLS using a newly developed non-conventional metal–matrix composite material composed of a metallic matrix (CuNi) and an advanced ceramic (ZrB2). The influence of important SLS parameters and material content on the densification behavior and porosity of the electrodes was investigated. EDM experiments were conducted to observe the electrodes behavior and performance. It was found that the ZrB2-CuNi electrodes could be successfully manufactured by SLS. Interlayer bonding and porosity are directly influenced by the layer thickness. Smaller layer thicknesses improved bonding between layers and decreased the porosity of the parts. The laser scan speed has a significant effect on the densification behavior. The scan line spacing affects the pore structure by means of overlapping. The surface morphology of the samples was not affected by varying the scan line spacing. The ZrB2-CuNi electrodes presented a much superior performance than SLS copper powder electrodes, but inferior to solid copper electrodes.

The cost of a part manufactured by Electrical Discharge 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 fifty percent 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 electrodes under adequate SLS conditions were manufactured. 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 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 newly composite electrodes possess superior performance when compared to copper powder electrodes made with SLS. The work also suggests important topics for future research work on this field.Copyright © 2013 by ASME