Rapid aluminum investment casting via indirect additive manufacturing with water-soluble sacrificial molds

Metallic lattice structures have garnered significant attention due to their unique combination of low density, high energy absorption, and excellent damping properties alongside the inherent toughness of metals. Traditional investment casting offers high-quality metallic components but is often constrained by costly, labor-intensive wax pattern fabrication. This study proposes an innovative approach that integrates additive manufacturing with conventional investment casting. Specifically, water-soluble polyvinyl alcohol (PVA) sacrificial molds are produced via fused deposition modeling (FDM) to form the negative of the desired lattice structure. Wax is then pressure-injected into these molds, and the PVA is subsequently dissolved, yielding detailed wax patterns ready for standard aluminum investment casting. This technique overcomes common limitations associated with directly printed sacrificial structures, such as the need for support removal and the presence of pyrolysis residues during the dewaxing process, while enabling the fabrication of complex geometries with high accuracy. Experimental results confirm the feasibility of the method, highlighting its potential for rapid prototyping and low-volume production of advanced metallic lattices.