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This paper focuses on the dispersion of ceramic powder in photosensitive resin. The effects of powder properties, dispersant type and dosage, and solid content on the rheological properties of stereolithography ZrO2 ceramic slurry were studied. The result shows that the properties of the powder have a significant impact on the rheological properties of the slurry, the use of ZrO2 powder with a smaller specific surface area and higher sphericity is more conducive to the preparation of low viscosity and high solid content slurry. The rheological properties and stability of the slurry are mainly controlled by the type and dosage of dispersant, using X-100 with a relative powder mass of 4% as a dispersant, the rheological properties and stability of the prepared ceramic slurry are better. The experimental result of the solid content of the slurry shows that the relationship between the solid content of the slurry and the viscosity satisfies the Krieger-Dougherty model. And the dispersion mechanism of the dispersant has been studied. By the research of this experiment, the foundation has been laid for the high-precision molding of the light-cured ZrO2 ceramic slurry. [ABSTRACT FROM AUTHOR]

A composite dispersant was selected to prepare low-viscosity ceramic slurry, and the thick-walled (>3 mm) SiO2 hollow hexagonal ceramic part was prepared by the self-developed ceramic 3D printer and DLP (digital light processing) process. The accuracy of the green body was all within 50 pm in three dimensional directions. The thermal decomposition process of 3D printing ceramic green bodies in air atmosphere or argon atmosphere was analyzed, and the influence of atmosphere on the degreasing and sintering of thick-walled (>3 mm) SiO2 ceramic parts was analyzed. The process of rapid degreasing and sintering of thick-walled (>3 mm) 3D printing SiO2 ceramic body was analyzed by SEM. The argon atmosphere is conducive to the rapid degreasing and sintering of the thick-walled SiO2 ceramics. The thick-walled (> 3 mm) SiO2 ceramic part was prepared rapidly by controlling the gas flow in argon atmosphere. The period of degreasing and sintering is greatly shortened to 21.8 h. Compared with the preparation period of the slurry and its process imported from a foreign company (The preparation period of the company's slurry and process to prepare the same product is 283 h), it is shortened by 92.3%. And it is more than 82% shorter than the preparation period of the SiO2 ceramic hollow blade prepared by the same process in public reports, which reflects the advantages of 3D printing formless rapid prototyping technology, and has great significance for the practical application of SiO2 ceramic 3D printing technology. [ABSTRACT FROM AUTHOR]

The thermal decomposition of Leightonite, K2Ca2Cu (SO4)4·2H2O, was studied by thermal gravimetric analysis(TGA), differential thermal analysis(DTA), X-ray diffraction(XRD), etc. The results show that the Leightonite is dehydrated around 170 °C to 390 °C and transformed to be new intermediate (K-Cu-SO4) sulphate salt with bright-green color. Moreover, the chemical structure changes during the thernal decomposition process was describled in detail. And the as-resulting phases are demonstrated to be K2Ca2(SO4)3, K2SO4, CaSO4, and Cu2O. [ABSTRACT FROM AUTHOR]