Increasing the service life of electrodes for Contact Arc Metal Grinding using additively manufactured metal matrix composites

This paper explores the application of additive manufacturing to extend the service life of the electrodes used in Contact Arc Metal Grinding (CAMG), a thermal underwater cutting process employed inter alia in nuclear decommissioning. One of the many challenges faced in nuclear dismantling with CAMG is the rapid wear of the electrodes, which requires innovative solutions for increased operational efficiency. Using additive manufacturing, the feasibility of creating customised material solutions tailored to the specific requirements of individual load cases was investigated. The focus of this study was the application of a particle composite material in the circumferential area of the electrode. This successful integration of additive manufacturing techniques with metal matrix composites into the production of electrodes opens up new avenues for improving the performance of the CAMG process. Fused tungsten carbide, chosen for its refractory properties, was incorporated into a copper-based metal matrix through laser-based directed energy deposition (L-DED). The aim was to evaluate the effectiveness of this approach in reducing electrode wear and improving cutting performance. By incorporating fused tungsten carbide, a significant increase in cutting length by a factor of 18 compared to a copper alloy was achieved (0.8 m–14.4 m). In this work, the prevailing wear mechanisms were examined in detail. Wear due to high temperatures was identified. However, mechanical wear for the ignition contact cannot be excluded. The results contribute to the advancement of thermal cutting processes, particularly in the context of nuclear decommissioning, where durable and efficient electrode materials are of paramount importance.