Energy Reduction in Powder Atomization by Novel Production Process for Recycled Titanium Electrodes

The established process chain for fabrication of titanium powder for additive manufacturing (AM) consists of the production of titanium sponge, the forging of electrodes and the atomization. A high energy demand of about 85% of the overall process energy consumption is taken by the production of the electrodes, resulting in a high carbon dioxide footprint and costs. This paper introduces a novel process chain to recycle titanium chips from milling and powder residues directly for the use in fabrication of electrodes. A methodology to increase the recyclability of the chips by adapting the process parameters of the milling process is shown. Cleaning and compaction to electrodes by utilizing hot isostatic pressing enables the possibility to use titanium chips and powder residues as base material for atomization. By using this novel recycling process, the energy demand for the production of titanium powder can be significantly reduced by approximately 72% in comparison to standard powder production.