Investigation of the Phase Composition and Analysis of the Properties of Sintered and Hot-Pressed Materials Based on Silicon Nitride

Перевислов, С. Н.

doi:10.1007/s11148-022-00682-0

Cited by 5 publications

(3 citation statements)

References 34 publications

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“…Besides the chemical composition, the sintering kinetics will depend strongly on the particle size distribution for each component, on the method (and the homogeneity) of mixing the powders as well as on the sintering method. Recommendations for sintering additives known from the literature are based on traditional grinding and mixing methods and generally refer to hot pressing [7,18,20,21].…”

Section: Introductionmentioning

confidence: 99%

Spark Plasma Sintering of Si3N4 Ceramics with Y2O3–Al2O3 (3%–10% wt.) as Sintering Additive

et al. 2023

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The ceramic samples fabricated by spark plasma sintering of powder mixtures based on silicon nitride (Si3N4) were investigated. The powder mixtures were made by wet chemical methods from commercial α-Si3N4 powder (the particle size <5 μm) and Y2O3-Al2O3 sintering additive (3% to 10% wt.). Sintering was carried out at the heating rate of 50 °C/min and the load of 70 MPa until the shrinkage end. The powder mixtures and ceramic samples were characterized by scanning electron microscopy and X-ray diffraction. The shrinkage of the powder mixtures during sintering was analyzed, and the activation energy of sintering was calculated according to the Young-Cutler model. The density, microhardness, and fracture toughness of the ceramic samples were also measured. All samples had high relative densities (98%–99%), Vickers microhardness 15.5–17.4 GPa, and Palmquist fracture toughness, 3.8–5.1 MPa∙m1/2. An increase in the amount of sintering additive led to a decrease in the shrinkage temperature of the powder mixtures. The amount of β-Si3N4 in the ceramics decreased monotonically with the increasing amount of sintering additive. The shrinkage rate did not decrease to zero when the maximum compaction was reached at 3% wt. of the sintering additive. On the contrary, it increased sharply due to the beginning of the Si3N4 decomposition.

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Section: Introductionmentioning

confidence: 99%

Spark Plasma Sintering of Si3N4 Ceramics with Y2O3–Al2O3 (3%–10% wt.) as Sintering Additive

et al. 2023

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“…Among advanced sintering technologies, hot pressing sintering is a mechanical pressure sintering method, which puts the ceramic powder or green body in the mold cavity with pressure assistance [ 23 , 24 , 25 , 26 ]. Due to the driving force supplied by the external pressure, the compaction can be achieved in a short time, and the microstructure with fine and uniform crystals can be obtained [ 27 , 28 , 29 , 30 ].…”

Section: Introductionmentioning

confidence: 99%

Microstructure and Properties of Hot Pressing Sintered SiC/Y3Al5O12 Composite Ceramics for Dry Gas Seals

Zou,

Ou,

Zhou

et al. 2024

Materials

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Silicon carbide (SiC) ceramics with high bending strength were prepared by hot pressing sintering (HPS) with yttrium aluminum garnet (Y3Al5O12, YAG) as sintering additive, and the effects of YAG content and sintering temperature on the sintering behavior, microstructure and mechanical properties of SiC ceramics were investigated in detail. The uniform distribution of YAG to form a liquid phase and the driving force provided by hot pressing sintering decrease the sintering temperature, improve the densification of SiC ceramics, and refine the crystal size. By means of suitable sintering conditions with the additional amount of YAG of 5 wt%, the sintering temperature of 1950 °C and a pressure of 30 MPa, the resultant SiC/YAG composite ceramics possesses high sintering and mechanical properties with the relative density of 98.53%, the bending strength of 675 MPa, the Vickers hardness of up to 17.92 GPa, and the elastic modulus of 386 GPa. The as-prepared SiC/YAG composite ceramics are promisingly used as the dry gas seal materials in the centrifugal compressors.

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“…In the case of radiation and thermal exposure, special active and plasticizing additives that contribute to the strengthening of composite material can play a significant role. For example, the use of amorphous silica as an active additive makes it possible to ensure the process of self-healing of emerging microcracks in concrete and increase the mechanical strength of the structure [30]. Therefore, the use of alkoxysilanes (tetraalkoxysilanes) as an additive in concrete is a promising research field.…”

Section: Introductionmentioning

confidence: 99%

Application of Organosilicon Modifier Based on Tetraethoxysilane for the Production of Heat-Resistant Chrysotile Fibers and Reinforced Cement Composites

Yastrebinsky,

Pavlenko,

Yastrebinskaya

et al. 2023

Fibers

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This research is aimed at obtaining boron-containing nanotubular chrysotile fibers with increased neutron absorption capacity. The possibility of using an organosilicon modifier based on tetraethoxysilane to increase the hydrothermal stability of chrysotile, as well as the strength of nanoreinforced composites based on a cement binder is considered. The mechanisms for the synthesis of heat-resistant nanotubular fibers of the composition Mg6(OH)8SiB4O10, which have a chrysotile structure, have been established. To increase the hydrothermal stability of chrysotile, crystalline hydrate phases were localized inside nanotubes using amorphous silica formed as a result of hydrolysis of silicon alkoxide under hydrothermal conditions in an alkaline environment. The modification of chrysotile via amorphous silica increases its hydrothermal stability by 97 °C. It is shown that the introduction of an organosilicon modifier based on tetraethoxysilane into the composition of Portland cement composite material leads to an increase in the structural strength and density of the composite due to the activation of silicate formation processes in the cement matrix, especially under hydrothermal conditions. The experiments showed that the strength of silicon alkoxide-modified samples of composite material increased by 34%.

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Investigation of the Phase Composition and Analysis of the Properties of Sintered and Hot-Pressed Materials Based on Silicon Nitride

Cited by 5 publications

References 34 publications

Spark Plasma Sintering of Si3N4 Ceramics with Y2O3–Al2O3 (3%–10% wt.) as Sintering Additive

Spark Plasma Sintering of Si3N4 Ceramics with Y2O3–Al2O3 (3%–10% wt.) as Sintering Additive

Microstructure and Properties of Hot Pressing Sintered SiC/Y3Al5O12 Composite Ceramics for Dry Gas Seals

Application of Organosilicon Modifier Based on Tetraethoxysilane for the Production of Heat-Resistant Chrysotile Fibers and Reinforced Cement Composites

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