Variation of porosity and pore size during post-sintering of reaction-bonded silicon nitride doped with Y&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; and MgO additives

Matsunaga, Chika; Zhou, You; Kusano, Dai; Hyuga, Hideki

doi:10.2109/jcersj2.19036

Cited by 6 publications

(5 citation statements)

References 12 publications

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“…The addition of different contents of α-Si 3 N 4 has no significant effect on the phase compositions of the porous silicon nitride with different porosity. The main phase was β-Si 3 N 4 and no α-Si 3 N 4 phase was observed, which indicated that the phase transition of α-Si 3 N 4 to β-Si 3 N 4 has been completed, and there was a small amount of glass phase Y 8 Si 4 N 4 O 14 observed [7]. The raw materials and sintering process of the intermediate layer and the superficial layers of porous laminated silicon nitride are exactly the same as the raw materials and sintering process of single layer porous silicon nitride.…”

Section: Resultsmentioning

confidence: 99%

The study on the microstructure and mechanical properties of porous laminated ceramics composite

Lu,

Bi,

et al. 2024

Ninth International Conference on Energy Materials and Electrical Engineering (ICEMEE 2023)

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The porous silicon nitride ceramics were prepared by carbothermic reduction-pressureless sintering with SiO 2 and α-Si 3 N 4 in nitrogen. By changing the relative content of α-Si 3 N 4 , SiO 2 and C powder in the raw material, the porosity controlled porous silicon nitride that consists mostly of the β-Si 3 N 4 grains was formed. The porous laminated silicon nitride ceramics composite with three layers were fabricated by this technique. The influence of the α-Si 3 N 4 content for the intermediate layer on the properties of the porous laminated silicon nitride ceramics composite was researched. When the linear shrinkage of the intermediate layer and superficial layer was very different, although it was a weak interfacial bonding, but the interfacial residual stress was very beneficial to the mechanical properties of the porous laminated silicon nitride. When the linear shrinkage and porosity of the intermediate layer and superficial layer were similar, it caused the conversion of weak interfacial bonding into the strong interfacial bonding. The three-layer porous laminated silicon nitride ceramics composite exhibited outstanding mechanical properties.

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Section: Resultsmentioning

confidence: 99%

The study on the microstructure and mechanical properties of porous laminated ceramics composite

Lu,

Bi,

et al. 2024

Ninth International Conference on Energy Materials and Electrical Engineering (ICEMEE 2023)

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“…Because there was no addition of -Si3N4 grains for sample S0, the spontaneous nucleation rate was slow and the number of nucleation was limited, and the nucleation process of -Si3N4 grains was suppressed and grown abnormally, so there were coarse equiaxed β-Si3N4 grains for the sample S0. Because there was addition of 5wt% -Si3N4 grains for sample S5 that has more nucleation sites [4]. In addition to -Si3N4 grains nucleation and growth spontaneous, the nucleation and growth of -Si3N4 grains was directly on the crystal surface of the -Si3N4 seeds, which accelerated growth rate of -Si3N4 grains.…”

Section: Solid State Phenomena Vol315mentioning

confidence: 99%

The Study on Porosity Controllable Filter Material for the Integrated Gasification Combined Cycle

Ding

Yun

et al. 2021

SSP

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The porous ceramic filter material is the most effective filter materials in the integrated gasification combined cycle. The porous silicon nitride due to its higher mechanical strength, as well as good corrosion resistance, is considered as a promising material in the integrated gasification combined cycle, and it were prepared directly though the SiO2 and α-Si3N4 through carbothermal reduction - pressureless sintering in nitrogen. There was a great lot weight loss in this reaction, so it was expected to create the high porosity materials. The rod-like β-Si3N4 grains and uniform pores were formed through changing the content of α-Si3N4, SiO2 and C. So high-performance and porosity controlled porous silicon nitride filter material was obtained. With an increasing in the α-Si3N4 content, the weight loss, the linear shrinkage, and the porosity decreased, the flexural strength increased accordingly. The porous silicon nitride filter material with addition of 50wt% α-Si3N4 showed a higher aspect ratio β-Si3N4 grains and better mechanical properties .

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“…Compared to diborides like ZrB 2 , oxides typically exhibit lower melting points, which leads to the formation of liquid phases or other reactions that facilitate sintering. For example, Si 3 N 4 ceramic sintering frequently utilizes Y 2 O 3 and Yb 2 O 3 as sintering additives, while also occasionally including Al 2 O 3 and MgO [18][19][20]. SiC presents challenges in sintering for densification due to its high covalent bond ratio.…”

Section: Introductionmentioning

confidence: 99%

Modification of LaB6 with ZrO2-Al2O3-TiO2 for Improvement of Density and Mechanical and Electrical Properties

Yang,

Ba,

Hong

et al. 2024

Crystals

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Pure lanthanum hexaboride (LaB6) ceramics were prepared using powders of different grain sizes. The ceramics could reach a relative density of 98.2% at high temperatures and pressures, but had a low flexural strength (136.9 MPa). LaB6 ceramics were synthesized using ZrO2-Al2O3-TiO2 (ZAT) as sintering additives. The ceramics demonstrate high density and excellent mechanical properties. The hot pressure sintering (HPS) method was utilized in the synthesis of the ceramics. Investigations were conducted on the effects of ZAT content, as well as the effects of the sintering temperature and pressure on the sintering behavior, microstructure, and mechanical and electrical properties of LaB6 ceramics. LaB6 ceramics fabricated with a ZAT addition of 6 wt.%, at a sintering temperature of 1700 °C, and under a pressure of 50 MPa, exhibited superior sintering and electrical properties, including a relative density of 97%, a conductivity of 7.2 MS/m, a flexural strength of 281.5 MPa, and a Vickers hardness of 21.2 GPa. The LaB6 ceramics synthesized in this research exhibit promising potential as electron-emitting cathodes for field emission applications.

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Variation of porosity and pore size during post-sintering of reaction-bonded silicon nitride doped with Y<sub>2</sub>O<sub>3</sub> and MgO additives

Cited by 6 publications

References 12 publications

The study on the microstructure and mechanical properties of porous laminated ceramics composite

The study on the microstructure and mechanical properties of porous laminated ceramics composite

The Study on Porosity Controllable Filter Material for the Integrated Gasification Combined Cycle

Modification of LaB6 with ZrO2-Al2O3-TiO2 for Improvement of Density and Mechanical and Electrical Properties

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