Jet electrochemical machining of selective laser melted metals for micro injection moulds
Jet ECM Bearbeitung von lasergeschmoltenen Metallwerkstoffen für Mikrospritzgusswerkzeuge
In micro injection moulding, complicated moulds with complex micro shapes are needed to create high precision micro parts. Moulds with complicated shapes can be fabricated in a resource efficient way by additive manufacturing, i.e. through Selective Laser Melting (SLM). To create the final shape with required accuracy, electrochemical machining (ECM) represents a promising manufacturing technique. While ECM of melting metallurgical steels has already been investigated in many ways, the machining of selective laser melted alloys has not been investigated sufficiently. Hence, it is not known if the grain boundaries of the laser-melted and re-solidified powder particles influence the result of the electrochemical erosions. In this study, Jet-Electrochemical Machining (Jet-ECM) of melting metallurgical steel 1.2709 and selective laser melted 18Ni-300 maraging steel with similar composition is presented. Point erosions without nozzle movement and linear erosions with single- and multi-axis motions of the tool were carried out. The machined shapes were analysed by confocal microscopy in order to measure their lateral and vertical dimensions as well as the resulting surface finish and to compare the results of both materials.