The preparation of zirconia slurry based on DLP additive manufacturing technology

In the research of digital light processing (DLP)-based ceramic three-dimensional printing technology, one of the key steps is to prepare proper slurry. Zirconia slurries were made of near-spherical zirconia powder and self-designed ultraviolet (UV) light curing resin system by the introduction of different dispersants in this paper. The effect of the dispersant types and concentrations on the rheological properties and stabilities of the slurries were investigated by means of rotary rheometer, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FT-IR). The results show that the dispersants Oleic acid (OA), sodium polyacrylate (PAA-Na), ammonium polyacrylate (PAA-NH4) and ammonium citrate (AC) can be successfully coated on the surface of zirconia particles and are beneficial to disperse these particles and prevent them from aggregating. But OA has the best effect to improve the rheological property and stability, and the effect varies with its concentration, and the best of it is 0.5 wt%. And, the slurry can be cured by UV light with the wavelength of 405 nm through the mechanism of the cracking and polymerization of unsaturated C = C in the resin by initiating the mechanism of photoinitiator.