Influence of metallic matrix on the densification behavior of zirconium diboride copper nickel composite processed by laser sintering

Abstract

The production of 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 electrical discharge machining (EDM) electrodes. Laser sintering (LS) 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 LS is the selection of an appropriate material. This work investigated the direct production of EDM electrodes by means of the LS using a newly developed non-conventional metal-matrix composite material composed of a metallic matrix (CuNi) and an advanced ceramic (ZrB2). The influence of nickel content on the metallic matrix and the matrix content on the densification behavior and porosity of the electrodes processed by LS was investigated. It was found that the ZrB2–CuNi electrodes could be successfully manufactured by LS. It was verified that the addition of nickel in the metallic matrix improved the densification behavior of the samples. Higher levels of nickel content on the matrix resulted in loss of shape and distortion of the part. Influence of matrix content was also assessed, and it was observed that both samples processed with higher and lower amount of matrix presented some degree of curling from the building platform. The densification process and porosity of both samples processed with higher and lower matrix content did not improve the overall porosity.