Improved properties and microstructure of porous silicon nitride/silicon oxide composites prepared by sol–gel route

Zou, Chunrong; Zhang, Changrui; Li, Bin; Cao, Feng; Wang, Siqing

doi:10.1016/j.msea.2012.07.042

Cited by 12 publications

(4 citation statements)

References 18 publications

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“…Using sol-gel processing, parts such as heat shields for space shuttles are made using a combination of glass fibers of Al 2 O 3 -B 2 O 3 -SiO 2 (Nextel 312 fibers) with high-purity SiO 2 fibers. Unlike the powder or slurry precursors, sol-gel has many advantages such as less fiber damage, good chemical composition flexibility, low densification at temperatures, and improvement in oxidation behavior of infiltrated components [121,127]. The sol-gel method is simple, economical and efficient method to produce high quality coverage and has the capacity of sintering at low temperatures, between 200-600 °C.…”

Section: Sol -Gel Infiltrationmentioning

confidence: 99%

“…Due to its outstanding mechanical qualities, strong thermal shock protection, and erosive resistance, Si 3 N 4 ceramic is a prospective for tail rotors and photovoltaic systems. These ceramics are also potential material for electromagnetic windows which are nearly transparent to electromagnetic radiation in the frequency ranges and employed in modern systems [175,176]. Likewise, the composite boron nitride combines with SiC/SiC-Si are a suitable substance for both electronics field and photonic products, along with higher temperature activities [177].…”

Section: Electronicsmentioning

confidence: 99%

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A Review on Si-Based Ceramic Matrix Composites and their Infiltration Based Techniques

Radhika

Sathish

2022

Silicon

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This review paper aims to look at silicon-based ceramic matrix composites and infiltration-based approaches for them. There are many different types of infiltration-based manufacturing processes, each with its own set of features. The best technique is chosen depending on the needs and desired attributes. With these considerations in mind, any type of infiltration might be selected to meet the requirements. Silicon-based ceramics has been highly used in the fields of aerospace, medical, automobile, electronics, and other various industries so it is important to study about their applications as well. This review outlines the evolution of composites from early 7000 BCE to composites today and discussed about various infiltration techniques for manufacturing silicon based ceramic matrix composites. This article also gives the comprehensive review of general characteristics and mechanical properties of silicon-based composites used in a variety of engineering sectors. The application section entails the wide range of engineering fields with consideration of infiltration techniques, which would be helpful for researchers to study and correlate the different infiltration techniques for end applications.

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Section: Sol -Gel Infiltrationmentioning

confidence: 99%

Section: Electronicsmentioning

confidence: 99%

A Review on Si-Based Ceramic Matrix Composites and their Infiltration Based Techniques

Radhika

Sathish

2022

Silicon

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“…The various methods and additives utilized so far for enhancing the strength of the fused silica ceramics are summarized in Table 12. The fused-silica composites produced so far are nano-sized silica-silica [70], silica fibers (SiO 2f ) reinforcedsilica [8,82], 3D SiO 2f -SiO 2 [80,83], 2.5D braided silica fibers reinforced nitride (SFRN) [84], silicon nitride (Si 3 N 4 )-doped silica [85], air-oxidized silica and Si 3 N 4 [86], zirconia (ZrO 2 ) doped silica [34], alumina doped silica [87], β-Si 4 Al 2 O 2 N 6silica [10,88,89], and BN-silica [44][45][46][47][48]90] as listed in Table 12 [1,2,4,5,36,61]. Various dopants were also added to confer different properties to fused silica ceramics consolidated by several techniques [1,2].…”

Section: Fused-silica Ceramic Composites With Other Materialsmentioning

confidence: 99%

Slip-Cast Fused Silica Radomes for Hypervelocity Vehicles: Advantages, Challenges, and Fabrication Techniques

Ganesh¹,

Mahajan²

2020

Handbook of Advanced Ceramics and Composites

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Today, the development of ceramic radome materials for hyper velocity (> Mach 5) missiles is a top research priority for several countries for the purposes of both surveillance and combat. The ceramic materials with low and stable dielectric properties against frequency and temperature variation among others are especially important. The radome property requirement for missiles launched from surface-toair, air-to-surface, and air-to-air differs considerably. Moisture absorbing materials despite having desired dielectric and thermal properties are not suitable for radome applications as the dielectric constant of water is considerably huge (80.4). So far no single material has been identified to meet all the requirements of a high-speed radome application. The advantages and disadvantages associated with various ceramic radome materials have been presented and discussed in this chapter together with the information about the radome design with respect to the wall thickness vs. radar frequency (RF) signals, bore-sight error, and the importance as well as generation principle of Ogive radome shape. Among various materials investigated so far, the slip-cast fused silica (SCFS) has been identified to be superior for hypervelocity radome applications. Furthermore, SCFS radomes can be fabricated with near-net shape using aqueous colloidal suspensions. However, SCFS radomes suffer from poor mechanical strength and from low rain and abrasion resistance properties apart from having considerably high internal porosity (up to 18%). Various methods employed so far to improve the properties of SCFS radomes required for hypervelocity applications have been reviewed in this chapter while citing all the important references. Among the various fused-silica composites, the Nitroxyceram (SiO 2-BN-Si 3 N 4 composite) exhibits the best combination of properties required for radome applications, and it can be consolidated and densified by following conventional powder processing techniques prevalent at industry.

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“…Many processes have been used to prepare porous Si 3 N 4 ceramics, such as pore-forming agent [6], gel-casting [7], carbothermal nitridation [8], freeze drying [9] and reaction sintering [10]. For instance, a Si 3 N 4 -SiO 2 composite fabricated by hot-press sintering attained a porosity of 22.0% with a thermal shock resistance ∆T of 900 o C was reported by Zou et al [11]. Weng et al [12] fabricated porous Si 3 N 4 by 3D printing technology and reaction sintering with bending strength of 5.1 MPa and porosity of 74.3%.…”

Section: Introductionmentioning

confidence: 99%

Properties and Processing of Porous Si<sub>3</sub>N<sub>4</sub> Ceramics

Zhao

Wang

Shang

et al. 2014

KEM

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Porous silicon nitride (Si3N4) ceramics green were prepared by sol-gel and freeze drying processing. Al2O3and MgO were selected as sintering additives. Porous Si3N4ceramics were sintered at 1200~1300 °C. The porosity of porous Si3N4ceramics reached 60~80%, the pore size of porous Si3N4ceramics dried by freeze drying is less than 5μm. Two kinds of pores were formed, including open pores with pore size of 1~5μm and closed pores pore size with the nanometer level. The compression strength of porous Si3N4ceramics was 15~25MPa. Thermal conductivity of porous Si3N4ceramics was 0.08-0.1 W/m·K.

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Improved properties and microstructure of porous silicon nitride/silicon oxide composites prepared by sol–gel route

Cited by 12 publications

References 18 publications

A Review on Si-Based Ceramic Matrix Composites and their Infiltration Based Techniques

A Review on Si-Based Ceramic Matrix Composites and their Infiltration Based Techniques

Slip-Cast Fused Silica Radomes for Hypervelocity Vehicles: Advantages, Challenges, and Fabrication Techniques

Properties and Processing of Porous Si<sub>3</sub>N<sub>4</sub> Ceramics

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