DLP 3D printing of high strength semi-translucent zirconia ceramics with relatively low-loaded UV-curable formulations
Dmitrii Komissarenko, Simon Roland, Benedikt S.M. Seeber, Thomas Graule, Gurdial Blugan
Abstract
DLP 3D printing is one of the additive manufacturing techniques, which allows the fabrication of ceramic parts with a complex shape, precisely controlled internal architecture and fine surface finishing. The method is based on the layer-by-layer solidification of a photosensitive ceramic suspension via UV-light projection followed by debinding of organic components and sintering and generally requires a high solid content of the ceramic filler to achieve good sintered densification. The present article aims to explore the possibility of fabricating high strength, fully dense and semi-translucent zirconia parts with relatively low-loaded UV-curable systems using a low-cost desktop DLP printer designed for printing polymers. For the slurry preparation, tetragonal zirconia powders from three different suppliers were evaluated. It was shown that with 35 vol% of zirconia content slurries, it was possible to fabricate zirconia semi-translucent ceramics with a density of 99.6%. No cracks or pores larger than 1 μm were observed on the sintered parts. According to ball-on-3-ball mechanical tests performed on the 13 × 1 mm discs an average flexural strength of the printed zirconia ceramics was 1566 MPa and a maximum of 1964 MPa could be achieved.