RETRACTED ARTICLE: Development and application of copper–nickel zirconium diboride as EDM electrodes manufactured by selective laser sintering

Abstract

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.