Powder Removal from Ti-6Al-4V Cellular Structures Fabricated via Electron Beam Melting

Direct metal fabrication systems like electron beam melting (EBM) and direct metal laser sintering (also called selective laser melting) are gaining popularity. One reason is the design and fabrication freedom that these technologies offer over traditional processes. One specific feature that is of interest is mesh or lattice structures that can be produced using these powder-bed systems. One issue with the EBM process is that the powder trapped within the structure during the fabrication process is sintered and can be hard to remove as the mesh density increases. This is usually not an issue for the laser-based systems since most of them work at a low temperature and the sintering of the powder is less of an issue. Within the scope of this project, a chemical etching process was evaluated for sintered powder removal using three different cellular structures with varying mesh densities. All meshes were fabricated via EBM using Ti6Al4V powder. The results are promising, but the larger the structures, the more difficult it is to completely remove the sintered powder without affecting the integrity of the mesh structure.