T. O. Obolkina

• imet

Zirconia-toughened alumina (ZTA) powders with 20.0 wt.% of ZrO2 were synthesized using the coprecipitation method. Transmission electron microscopy indicated that the powders contained needle-like particles 15–30 nm long and 50–70 nm flake-like particles with a uniform component distribution. Effects of different Y2O3 concentrations (3.0, 4.0, or 5...

Calcium sulfate powder materials containing terbium ions at 0, 1.0, or 2.0 mol.% were obtained. They are characterized by the presence of a CaSO4 × 0.5H2O phase, while Tb3+ is incorporated into the lattice at ≤1.0 mol.%. Specific surface area enlarged from 2.1 to 22.5 m2/g as crystallite size decreased from 68 to 31 nm. Thermal analysis showed that...

Calcium sulfate (CS) materials containing terbium ions at 0, 1.0, or 2.0 mol.% were obtained by mechanochemical synthesis. According to X-ray diffraction data, the powder materials are characterized by the presence of a CaSO4×0.5H2O phase, while Tb3+ is incorporated into the lattice at ≤1.0 mol.%. Specific surface area enlarged from 2.1 to 22.5 m2/...

Powders based on β-tricalcium phosphate (β-TCP) containing sulphate groups at up to 12.0 mol.% were synthesised by chemical precipitation from aqueous solutions. The obtained materials were characterised by X-ray phase analysis, Fourier transform infrared spectroscopy, measurement of specific surface area, scanning electron microscopy, energy dispe...

Mesoporous hydroxyapatite (HA) materials demonstrate advantages as catalysts and as support systems for catalysis, as adsorbent materials for removing contamination from soil and water, and as nanocarriers of functional agents for bone-related therapies. The present research demonstrates the possibility of the enlargement of the Brunauer–Emmett–Tel...

In this work, the effect of a complex additives based on Na2Si2O5 and Mn2+ on the properties and sintering temperature of ZrO2 ceramic material stabilized with 3 mol. % Y2O3 — 2.5 wt. % Al2O3 (Z–A) was studied. It has been found that the introduction of complex additives increases the strength in three-point bending and the microhardness of ceramic...

In this work, we studied the effect of complex additives containing Na2Si2O5 and Ni, Zn oxides on the properties and sintering temperature of a ceramic material 3Y-TZP- Al2O3 with an aluminum oxide (Al2O3) content of 5 wt %. It was shown that the introduction of complex additives promoted an increase in the flexural strength of ceramic materials. T...

The article presents the results of 3D printing with ceramic suspensions by DLP method using inorganic dyes.

The effect of complex additives based on cobalt, iron, and manganese oxides and sodium silicate on the phase composition, microstructure, mechanical properties, and sintering of tetragonal zirconia ceramics stabilized with 3 mol % yttria and containing 10 wt % alumina (3Y–TZP–10Al2O3) was studied. The introduction of complex additives significantly...

We studied the effect of complex additives containing Na2Si2O5and Co, Fe oxides on the properties and sintering temperature of a ceramic material zirconium dioxide (ZrO2) with an aluminum oxide (Al2O3) content of 10 wt %. It was shown that the introduction of complex additives contributed to the intensification process and a significant increase in...

The effect of the introduction of Co2+ to ZrO2–10 wt % Al2O3 ceramic materials on their phase composition, porosity, microstructure, strength, microhardness, cytotoxicity, and cytocompatibility was studied. It was shown that the addition of Co2+ stabilizes the tetragonal form of ZrO2, which is the only form in sintering at 1400°С. An increase in th...

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....

We have synthesized powders and produced ceramic materials in the tricalcium phosphate–trimagnesium phosphate system with a degree of Mg2+ substitution for Ca2+ up to 40 wt %. It has been shown that increasing the percentage of magnesium in the materials reduces their sintering temperature from 1300 to 1100°C. We have determined the phase compositi...

We have prepared powders and ceramic composite materials in the ZrO2–Al2O3 system containing 10 and 20 wt % Al2O3 and examined the effect of ferric oxide additions on the linear shrinkage, phase composition, porosity, microstructure, and mechanical properties of the ZrO2–Al2O3 ceramic materials. The results demonstrate that the addition of ferric o...

The paper presents the results of the investigation of the transition metals oxides – cobalt and iron additives influence on the sintering and properties of the ceramic material based on ZrO 2 - Al 2 O 3 system with 10 wt.% Al 2 O 3 . It is shown that the addition of the oxides resulted in the significant increase of the sintered ceramic materials...

Calcium sulphate-based materials were synthesized and investigated, in which Ca2+ cations were substituted for Na+ or K+ cations in an amount of 5, 10 and 20 mol.%. With the introduction of Na+, materials with the structure semi-aqueous and two-water calcium sulfate were obtained, with the introduction of potassium, a mixture of calcium sulfates wi...

Materials based on calcium sulfate in which Na⁺ or K⁺ cations were substituted to a concentration of 5, 10, or 20 mol % for Ca²⁺ cations were synthesized and studied. The introduction of Na⁺ produced materials with the structure of calcium sulfate hemihydrate and dihydrate, and the incorporation of potassium yielded a mixture of calcium sulfates wi...

The dependences of the formation of the microstructure and the phase composition of ceramics based on partially stabilized zirconium dioxide on the sintering temperature and the content of the sintering additive are established. It is shown that the introduction of an additive, which forms a low-temperature melt based on sodium silicate - Na2SiO3,...

Dependences of the formation of the microstructure and phase composition of partially stabilized zirconia ceramics on the sintering temperature and the content of the sintering additive have been studied. It has been shown that introduction of an additive forming a low-temperature melt based on sodium silicate Na2SiO3 reduces the sintering temperat...

The results of investigation of sintering, microstructure and phase composition of the system ZrO2-Al2O3-SiO2 with MnO admixture are shown. It was approved that the usage of MnO admixture promoted sintering temperature decrease up to 1250-1350 °C. The product obtained is characterized by a high content of tetragonal phase as well as high strength w...

The sintering, microstructure, and phase composition of the eutectic ceramics of the ZrO2–Al2O3–SiO2 system with an MnO additive have been studied. It has been shown that the additive contributes to the decrease in the sintering temperature to 1250–1350°С. The synthesized materials have a high content of the tetragonal phase, a fine crystalline str...

The study of sintering, microstructure and phase composition of zirconia ceramics containing the additive - sodium niobate. It is shown that the use of an additive helps to reduce the sintering temperature to 1,400 ° C. The obtained materials are characterized by a high content of the tetragonal phase, a fine-crystalline structure and high strength...

The sintering, microstructure, and phase composition of zirconia ceramics containing a sodium niobate addition have been studied. It has been shown that the addition leads to a decrease in the sintering temperature to 1400°С. The resulting materials are characterized by a high content of the tetragonal phase, a fine-crystalline structure, and a hig...

The influence of lithium substitution for calcium over a broad concentration range (0–20 mol %) on the crystal lattice parameters, coherent scattering regions, and phase composition was studied for hydroxyapatite synthesized by precipitation from solutions and heat treatment at 900, 1200, and 1400°C. The lithium substitution in a more than 10 mol %...

Agglomeration of ceramics of partially stabilized zirconium dioxide containing 5 wt % of aluminum oxide depending on the amount of additive (iron oxide) was studied. It was shown that introduction of an additive promotes a decrease in agglomeration temperature to 1400–1450°С and formation of a dense structure, as well as acquisition of high strengt...

We have studied the influence of the sintering temperature, Al2O3 additions, and liquid-forming sintering aids on the phase composition and microstructure of fluorohydroxyapatite-based composite ceramic materials containing 20 and 60% zirconia. The addition of alumina has been shown to prevent secondary recrystallization processes during sintering...