Innovative 3D-Manufacturing of Complex Ceramic Parts by Means of Commercial Digital Light Processing Apparatus

Additive Manufacturing technologies have been acknowledged for years as tremendous processing routes for the production of parts with complex shape. While the economic Digital Light Processing (DLP) technology was initially restricted to the production of photopolymer materials, it has a great potential for the manufacture of ceramic and metallic parts, half way between direct prototyping and the conventional powder processing route. The method consists in preparing a powder-loaded photopolymer slurry by conventional ball milling, processing green composite parts by DLP and carrying a debinding and sintering heat treatment. The present report investigates the preparation of a suitable slurry and evaluate the printability by DLP. It was found that viscosity of the slurry significantly increased with increasing powder contents, particularly over 25 vol.%. A 28 vol.% Al2O3 powder containing green composite was successfully processed using a commercial DLP apparatus. However, higher loads of powder are required to allow for appropriate sintering, which suggests optimization of the slurry by addition of solvents and use of finer powder particles to reduce viscosity and enhance printability. Key words: Additive manufacturing, Digital light processing, Powder processing, Viscosity, Composite