Porous Silicon Carbide Ceramics Produced by a Carbon Foam Derived from Mixtures of Mesophase Pitch and Si Particles

Zhang, Zhijin; Wang, Fuchi; Yu, Xiaodong; Wang, Yangwei; Yan, Yi; Li, Kai; Liu, Zhiqiang

doi:10.1111/j.1551-2916.2008.02842.x

Cited by 24 publications

(9 citation statements)

References 16 publications

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“…In this, the pyrolyzed wood infiltrated with silica sol and molten silicon is subjected to carbothermal reduction and siliconization, respectively, at high temperature to produce the SiC foams. Recently, the carbon foams prepared from coal tar or petroleum pitch are also used as a template for the preparation of SiC foams by silicon infiltration and siliconization . In this, a portion of the required silicon powder is incorporated in the precursor pitch before foaming and the foam obtained is subsequently carbonized.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, the carbon foams prepared from coal tar or petroleum pitch are also used as a template for the preparation of SiC foams by silicon infiltration and siliconization. 36 In this, a portion of the required silicon powder is incorporated in the precursor pitch before foaming and the foam obtained is subsequently carbonized. The remaining silicon is incorporated in the carbonized body by infiltration in the molten state.…”

Section: Introductionmentioning

confidence: 99%

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Low‐Density Open Cellular Silicon Carbide Foams from Sucrose and Silicon Powder

et al. 2016

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Open cellular SiC foams with low densities were prepared by thermo‐foaming and setting (130°C–150°C) of silicon powder dispersions in molten sucrose followed by pyrolysis and reaction sintering at 1500°C. The bubbles generated in the dispersion by water vapor produced by the –OH condensation was stabilized by the adsorption of silicon particles on the air‐molten sucrose interface. The composition of a sucrose‐silicon powder mixture for producing SiC foam without considerable unreacted carbon was optimized. The sucrose in the thermo‐foamed silicon powder dispersion leaves 24 wt% carbon during the pyrolysis. The sintering additives such as alumina and yttria promoted the silicon‐carbon reaction. SiC nanowires with diameters in the range of 35–55 nm and length >10 μm observed on the cell walls as well as in the fractured strut region were grown by both vapor–liquid–solid and vapor–solid mechanisms. Large SiC foam bodies without crack could be prepared as the total shrinkage during pyrolysis and reaction sintering was only ~30 vol%. The relatively low compressive strength (0.06–0.41 MPa) and Young's modulus (14.9–24.2 MPa) observed was due to the large cell size (1.1–1.6 mm) and high porosity (93%–96%).

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Low‐Density Open Cellular Silicon Carbide Foams from Sucrose and Silicon Powder

et al. 2016

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“…Figure 12 shows the flexural strength of the newly developed porous SiC ceramics as a function of the porosity, and a comparison with literature values 34,40,45,81–87 . The flexural strengths of the newly developed porous SiC ceramics sintered in argon (SCA) and nitrogen (SCN) atmospheres increase from 8.6 to 32.9 MPa and from 8.1 to 27.9 MPa while decreasing the porosity from 68.2 to 58.3% and from 70.3 to 61.7%, respectively.…”

Section: Resultsmentioning

confidence: 95%

Electrical, thermal, and mechanical properties of porous silicon carbide ceramics with a boron carbide additive

Kultayeva

Kim

2022

Int J Applied Ceramic Tech

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The effects of the boron carbide (B4C) content and sintering atmosphere on the electrical, thermal, and mechanical properties of porous silicon carbide (SiC) ceramics were investigated in the porosity range of 58.3%–70.3%. The electrical resistivities of the nitrogen‐sintered porous SiC ceramics (∼10–1 Ω·cm) were two orders of magnitude lower than those of argon‐sintered porous SiC ceramics (∼101 Ω·cm). Both the thermal conductivities (3.3–19.8 W·m–1·K–1) and flexural strengths (8.1–32.9 MPa) of the argon‐ and nitrogen‐sintered porous SiC ceramics increased as the B4C content increased, owing to the decreased porosity and increased necking area between SiC grains. The electrical resistivity of the porous SiC ceramics was primarily controlled by the sintering atmosphere owing to the N‐doping from the nitrogen atmosphere, and secondarily by the B4C content, owing to the B‐doping from the B4C. In contrast, the thermal conductivity and flexural strength were dependent on both the porosity and necking area, as influenced by both the sintering atmosphere and B4C content. These results suggest that it is possible to decouple the electrical resistivity from the thermal conductivity by judicious selection of the B4C content and sintering atmosphere.

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“…The SiC foams with a wide range of porosity and pore architecture are prepared either from SiC powder suspensions or preceramic polymers. Polymer foam replication, direct foaming, freeze‐casting and emulsion templating methods are used for the preparation of SiC foams from both SiC powder suspensions and preceramic polymers . In addition, SiC foams with unidirectional cellular pore structure are prepared by infiltrating pyrolyzed wood template with silicon in the molten or vapor phase .…”

Section: Introductionmentioning

confidence: 99%

Nanowire‐decorated SiC foam from tissue paper and silicon powder by filter‐pressing

Wilson

Vijayan

Prabhakaran

2019

Int J Applied Ceramic Tech

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A facile and scalable method for the preparation of low‐density SiC foam from tissue paper and silicon powder is reported. The co‐dispersion of pulp‐containing tissue paper micro‐ribbons and silicon powder is coagulated by adjusting the pH to 3.5. The silicon particles adhere to the tissue paper micro‐ribbons during the coagulation. The coagulated co‐dispersion on filter‐pressing consolidates the silicon particle‐decorated tissue paper micro‐ribbons and orients them perpendicular to the filter‐pressing direction. The filter‐pressed body on drying followed by heat treatment at 1600°C in inert atmosphere produces SiC foam. The tissue paper micro‐ribbons retain their morphology during carbonization as well as high‐temperature reaction with the silicon. The enormous growth of carbon‐rich SiC nanowires is observed on the SiC micro‐ribbons. The random orientation of SiC micro‐ribbons in the X‐Y plane with the hairy nanowires on the surface and their stacking in the Z‐direction produces a porosity of ~94 vol.% with pore sizes in the range of 0.08 to 20 µm. The SiC foam shows a compressive strength and Young's modulus of 0.22 and 5.5 MPa, respectively. The thermal conductivity decreases from 0.11 to 0.07 W m−1 K−1 when temperature increases from 25°C to 350°C.

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Porous Silicon Carbide Ceramics Produced by a Carbon Foam Derived from Mixtures of Mesophase Pitch and Si Particles

Cited by 24 publications

References 16 publications

Low‐Density Open Cellular Silicon Carbide Foams from Sucrose and Silicon Powder

Low‐Density Open Cellular Silicon Carbide Foams from Sucrose and Silicon Powder

Electrical, thermal, and mechanical properties of porous silicon carbide ceramics with a boron carbide additive

Nanowire‐decorated SiC foam from tissue paper and silicon powder by filter‐pressing

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