Preparation of high solid loading and low viscosity ceramic slurries for photopolymerization-based 3D printing

In this study, high solid loading and low viscosity cordierite slurries are successfully developed for the first time for photopolymerization-based additive manufacturing. The processability of the slurries is mainly determined by their rheological properties and photocuring parameters. The slurry preparation involves the orthogonal optimization of compositions in order to achieve suitable viscosity, stability and homogeneity. The photocuring parameters of the as-prepared slurries, including penetration depth Dp and critical exposure Ec, are also determined experimentally. Results show that viscosity increases with reduction in particle size. A higher solid-volume fraction also results in an exponential growth in viscosity. As for the dispersant amount, a concentration of 5 wt% leads to the lowest viscosity. Particle size also play an important role in the solid loading capacity of the slurries, as results suggest that smaller particles improve performance. In terms of the photocuring behaviors, the addition of 2 wt% photoinitiator generates an optimal curing process. 40 vol% solid loading leads to the thickest curing depth for all slurries with different types of particle sizes. Finally, a cordierite part with a complex hollow structure and a fine resolution is successfully fabricated. The present study offers a material basis for the polymerization-based 3D printing of porous cordierite structures.