Dense SiC-based ceramic materials containing yttrium aluminum garnet (YAG) as an oxide sintering aid have been prepared by hot pressing in the temperature range 1750–1850°C. As a result of melting, the oxides fill spaces between the SiC particles, contributing to the densification of the material and mass transport during the hot pressing process. The present results demonstrate that relatively small amounts of the oxides (≤5 wt %) are needed to ensure a high degree of densification of the SiC–YAG materials. The best physicomechanical properties are offered by the SiC + 3 wt % YAG material sintered at a temperature of 1850°C: ρ = 3.24 ± 0.01 g/cm³, П = 1.1 ± 0.1%, σ_b = 640 ± 10 MPa; K_Ic = 6.4 ± 0.2 MPa m^1/2, Еel = 410 ± 20 GPa, and HV = 26.0 ± 0.2 GPa. This material experiences predominantly intercrystalline fracture.

Nanocrystalline 3 mol% yttria-tetragonal zirconia polycrystal (3Y-TZP) ceramic powder containing 5 wt.% Al₂O₃ with 64 m²/g specific area was synthesized through precipitation method. Different amounts of Co (0–3 mol%) were introduced into synthesized powders, and ceramic materials were obtained by heat treatment in the air for 2 h at 1350–1550 °C. The influence of Co addition on the sintering temperature, phase composition, microstructure, mechanical and biomedical properties of the obtained composite materials, and on the resolution of the digital light processing (DLP) printed and sintered ceramic samples was investigated. The addition of a low amount of Co (0.33 mol%) allows us to decrease the sintering temperature, to improve the mechanical properties of ceramics, to preserve the nanoscale size of grains at 1350–1400 °C. The further increase of Co concentration resulted in the formation of both substitutional and interstitial sites in solid solution and appearance of CoAl₂O₄ confirmed by UV-visible spectroscopy, which stimulates grain growth. Due to the prevention of enlarging grains and to the formation of the dense microstructure in ceramic based on the tetragonal ZrO₂ and Al₂O₃ with 0.33 mol% Co the bending strength of 720 ± 33 MPa was obtained after sintering at 1400 °C. The obtained materials demonstrated the absence of cytotoxicity and good cytocompatibility. The formation of blue CoAl₂O₄ allows us to improve the resolution of DLP based stereolithographic printed green bodies and sintered samples of the ceramics based on ZrO₂-Al₂O₃. The developed materials and technology could be the basis for 3D manufacturing of bioceramic implants for medicine.

The effect of the content of temporary process binder (paraffin, oleic acid, and beeswax) in the range of 10–18% on the molding of the silicon carbide products using hot slip casting has been...

Aluminum oxynitride Al23O27N5was synthesized by solid phase synthesis from a stoichiometric mixture of aluminum nitride and aluminum hydroxide at 1850°C in a nitrogen atmosphere. Aluminum oxynitride...

The preceramic oligomer organomagnesiumoxanealumoxane was synthesized by the co-condensation of organoaluminoxane and magnesium acetylacetonate. Powders of magnesium aluminate spinel (MAS) were obtained by the pyrolysis of the oligomer at 700 and 1250°C. The effect of the pyrolysis temperature on the physicochemical and rheological properties of the powder was studied. With increasing pyrolysis temperature, the particle shape becomes closer to isometric, which leads to a decrease in the limiting length of the linear portion of the compaction curves. A MAS powder containing 3 wt % Sm₂O₃ was produced to study the effect of the sintering additive. The sintering kinetics was investigated by dilatometry, and the effect of the sintering additive Sm₂O₃ on the process and the mass-transfer mechanism during the sintering of spinel was estimated. According to the quantitative analysis data, the activation energies for the pure MAS and the MAS doped with Sm₂O₃ are Q₁₂₅₀ = 481 kJ/mol and Q_Sm2O3 = 775 kJ/mol, respectively. The sintering additive does not affect the mass-transfer mechanism; however, it increases the activation energy by 60%, doubles the shrinkage, and decreases the temperature of the beginning of sintering from 1546 to 1494°C.