ABSTRACT
SiO2 ceramic parts with complex structures were formed by additive manufacturing technology via a light curing method combined with a heat treatment process. To reveal the influence mechanism of rheology and formability of SiO2 ceramic slurry, the microstructure, morphology, and properties of light-cured SiO2 ceramic samples were characterized by a viscosity test, thermogravimetric analysis (TG-DTG), X-ray diffraction (XRD), a scanning electron microscope (SEM), and a series of tests for physical properties (bending strength, mass burning rate, and densification). The results indicate that the main effect of the dispersant-type factor was more significant than the pH value. When the dispersant was ammonium polyacrylate (PMAA-NH4) with a content of 1.0 wt % and the pH value of the slurry system was 9, the viscosity of SiO2 ceramic slurry could be controlled to the lowest. It was also found that the sintering temperature in the experiment had no effect on the crystalline phase of SiO2 ceramics. When the sintering temperature was 1250 °C and the solid content was 65 vol %, the micromorphology of the samples was uniform. Under this condition, the bending strength of the sample reached 14.9 MPa and the densification was 76.43%.
ABSTRACT
The use of three-dimensional (3D) printing technology to form ceramic materials can greatly reduce the technical difficulty and cost of preparing special-shaped ceramic parts. In this work, the formation of the 3D structure of ceramic products was achieved through light-curing 3D printing technology. The semi-solid ceramic precursor fluid prepared from nano alumina particles (Al2O3), photocurable polyurethane acrylate (PUA) and isobornyl methacrylate (IBOMA) resin was used to realize ceramic fluid with self-made light-curing 3D printing equipment. The solidification and forming of the ceramic material was achieved through secondary high temperature sintering. In order to reveal the influence mechanism of nano-alumina content in a ceramic slurry on the forming process and performance of light-curing 3D printing, the composition, micro morphology and mechanical properties of 3D printing ceramic samples under different preparation conditions were investigated. The research results show that the relationship of the ratio of alumina to the forming performance was not a monotonic function in the mathematical sense. When the mass ratio of the resin system and alumina was 1 : 2.50, the performance of the formed sample was the best. At this time, the Vickers strength of the sintered ceramic part was 79 GPa, the bending strength was 340 MPa, and the fracture toughness was 2.90 MPa m-2. This work laid a theoretical and practical foundation for the realization of high-quality, low-cost, and rapid ceramic manufacturing technology in the future.
