Porous Si3N4 ceramics prepared via partial nitridation and SHS

Yao, Dongxu; Xia, Yongfeng; Zuo, Kaihui; Jiang, Dongliang; Günster, Jens; Zeng, Yu‐Ping; Heinrich, Jürgen G.

doi:10.1016/j.jeurceramsoc.2012.08.033

Cited by 20 publications

(9 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is noteworthy that the linear shrinkage increases significantly at 10 vol% solid content, and the considerable shrinkage performance will change the porosity. Despite the fact that SHS completes both nitriding and sintering processes in a remarkably short period of time [24][25][26], the internal particle build-up of a low solid content (10 vol%) is so loose that dramatic sintering shrinkage occurs when the combustion wave passes through. It explains the increase in porosity when the solid content is increased from 10 to 15 vol%, which is consistent with the trend of porosity change in the green body.…”

Section: Resultsmentioning

confidence: 99%

“…The low-temperature eutectic phase formed by Y 2 O 3 with SiO 2 on the surface of Si 3 N 4 accelerates the atomic diffusion rate and boosts the development of elongated rod-like grains [15][16][17]. More importantly, the formation mechanism of Si 3 N 4 obtained by SHS is controlled by vapor-crystal (VC) mechanism [24][25][26]. The rapid increase in temperature (far beyond Si melting point) gives rise to a fast vaporization rate of Si and further react with N 2 , leading to the formation and growth of Si 3 N 4 on the surface of the both Si particles and Si 3 N 4 particles.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Microstructure and properties of porous Si3N4 ceramics by gelcasting-self-propagating high-temperature synthesis (SHS)

Chen

Wang

et al. 2021

J Adv Ceram

View full text Add to dashboard Cite

Porous silicon nitride ceramics have attracted a considerable attention due to their excellent overall performance, but poor porosity homogeneity and structural shrinkage induced by prolonged high temperature sintering limit its further application. Herein, as a three-in-one solution for the above issues, for the first time we develop a novel approach that integrates the merits of gelcasting-SHS (self-propagating high-temperature synthesis) to prepare porous Si3N4 ceramics to simultaneously achieve high porosity, high strength, high toughness, and low thermal conductivity across a wide temperature range. By regulating the solid content, porous Si3N4 ceramics with homogeneous pore structure are obtained, where the pore size falls inbetween 1.61 and 4.41 µm, and the elongated grains are interlaced and interlocked to form micron-sized coherent interconnected pores. At the same time, porous Si3N4 ceramics with porosity of 67.83% to 78.03% are obtained, where the compressive strength reaches 11.79 to 47.75 MPa and fracture toughness reaches 1.20 to 6.71 MPa·m1/2.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Microstructure and properties of porous Si3N4 ceramics by gelcasting-self-propagating high-temperature synthesis (SHS)

Chen

Wang

et al. 2021

J Adv Ceram

View full text Add to dashboard Cite

show abstract

“…Silicon nitride possesses low thermal expansion coefficient . high strength and stiffness, high thermal conductivity, outstanding thermal shock resistance, and excellent resistance to wear . Besides, α‐Si 3 N 4 is an important wide band gap semiconductor (5.3 eV), resulting in good optical and electrical properties.…”

Section: Introductionmentioning

confidence: 99%

Facile synthesis of α‐Si₃N₄ nanoneedles and their photoluminescence properties

Shen

Liu

Zhang

et al. 2019

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

Needle-like α-Si 3 N 4 with unique structures has potential application in both field emission devices and tips for atomic force microscopes. Single-crystalline, α-Si 3 N 4 nanoneedles have been prepared by using an improved chemical vapor deposition (CVD) method at 1200°C for 3 hours. The phases, chemical composition, and microstructure of the as-prepared products were determined by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) equipped with EDS. The as-synthesized products show a needle-like morphology with hundreds of micrometers in length and nanometer-featured tips. The nanoneedles show a α-Si 3 N 4 @SiOx core-shell heterostructure as characterized by TEM, with single-crystalline α-Si 3 N 4 core and an insulating amorphous silicon oxide shell. The growth of α-Si 3 N 4 nanoneedles corresponds to vapor-liquidsolid cap-growth and base-growth mechanism. Photoluminescence (PL) properties of the products were also characterized. An obvious emission peak at 400 nm under 254 nm UV excitation was observed. The nanoneedle morphology and photoluminescence properties of the products have potentials to be used in future optoelectronic nanodevices. K E Y W O R D SCVD, growth mechanism, nanoneedles, photoluminescence, α-Si 3 N 4 2374 | SHEN Et al.

show abstract

“…[1][2][3][4][5] For the porous Si 3 N 4 ceramics, it is important to tailor the porosity and mechanical properties for the applications, such as filter, random, and catalyst supports. [1][2][3][4][5] For the porous Si 3 N 4 ceramics, it is important to tailor the porosity and mechanical properties for the applications, such as filter, random, and catalyst supports.…”

Section: Introductionmentioning

confidence: 99%

“…P OROUS silicon nitride (Si 3 N 4 ) ceramics show superior mechanical properties, such as high strength, good thermal shock resistance, high strain and damage tolerance, gaining interest for a numerous engineering applications, at room or high temperatures including molten metal filters, catalyst supports, sensors, and separation membranes. [1][2][3][4][5] For the porous Si 3 N 4 ceramics, it is important to tailor the porosity and mechanical properties for the applications, such as filter, random, and catalyst supports. Sometimes porosity higher than 50% was desirable to get good permeability and low dielectric constant; however, it is not easy to get due to the shrinkage, which was dependent on the quality of the starting powder, such as particle size and impurity.…”

Section: Introductionmentioning

confidence: 99%

Preparation of Porous Si₃N₄ Ceramics with Controlled Porosity and Microstructure by Fibrous α‐Si₃N₄ Addition

Wang

Yang

et al. 2014

J. Am. Ceram. Soc.

View full text Add to dashboard Cite

Porous silicon nitride ceramics with various porosities were fabricated by liquid phase sintering of mixtures containing fibrous and equiaxed α‐Si3N4 powder with a various content ratios. The effects of the contents of the fibrous α‐Si3N4 powder (0%–100%) on the microstructure and mechanical properties of porous Si3N4 ceramics were studied. As the increase of the fibrous α‐Si3N4 powder content, both the density of green bodies and the linear shrinkage decreased, resulting in increased porosity due to the inhibited densification by the fibrous Si3N4 particle. XRD analysis proved the complete formation of single β‐Si3N4 phase. SEM analysis revealed that the microstructure of the low content of fibrous α‐Si3N4 porous ceramics was almost composed of fine elongated β‐Si3N4 grains with high aspect ratio while numerous coarse elongated β‐Si3N4 grains with low aspect ratio surrounding fine grains were formed as the content of the fibrous α‐Si3N4 powder increased. With the increase in content of the fibrous α‐Si3N4 powder from 0% to 100%, the porosity changed from 47.8% to 56.6%, and the flexural strength decreased from 146 to 62 MPa correspondingly, indicating a flexural adjustment of the porosity and mechanical properties.

show abstract

Porous Si3N4 ceramics prepared via partial nitridation and SHS

Cited by 20 publications

References 23 publications

Microstructure and properties of porous Si3N4 ceramics by gelcasting-self-propagating high-temperature synthesis (SHS)

Microstructure and properties of porous Si3N4 ceramics by gelcasting-self-propagating high-temperature synthesis (SHS)

Facile synthesis of α‐Si₃N₄ nanoneedles and their photoluminescence properties

Preparation of Porous Si₃N₄ Ceramics with Controlled Porosity and Microstructure by Fibrous α‐Si₃N₄ Addition

Contact Info

Product

Resources

About

Porous Si3N4 ceramics prepared via partial nitridation and SHS

Cited by 20 publications

References 23 publications

Microstructure and properties of porous Si3N4 ceramics by gelcasting-self-propagating high-temperature synthesis (SHS)

Microstructure and properties of porous Si3N4 ceramics by gelcasting-self-propagating high-temperature synthesis (SHS)

Facile synthesis of α‐Si3N4 nanoneedles and their photoluminescence properties

Preparation of Porous Si3N4 Ceramics with Controlled Porosity and Microstructure by Fibrous α‐Si3N4 Addition

Contact Info

Product

Resources

About

Facile synthesis of α‐Si₃N₄ nanoneedles and their photoluminescence properties

Preparation of Porous Si₃N₄ Ceramics with Controlled Porosity and Microstructure by Fibrous α‐Si₃N₄ Addition