Pressure-pulsed chemical vapour infiltration of SiC to porous carbon from a gas system SiCl4-CH4-H2

Sugiyama, Kohzo; Kishida, Takayoshi

doi:10.1007/bf00352776

Cited by 17 publications

(5 citation statements)

References 10 publications

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“…La tŽcnica consiste en la infiltraci-n de gases a una temperatura y presi-n determinadas que reaccionan entre s' o con el sustrato originando el compuesto buscado. La porosidad residual remanente m'nima que se obtiene empleando esta tŽcnica es del 6% en las mejores condiciones de ensayo (21,(75)(76)(77)(78)(79)(80). En general, la reducci-n de porosidad reduce la velocidad de oxidaci-n y de corrosi-n frente a diferentes productos.…”

Section: -Infiltraciîn De La Porosidad Residualunclassified

Materiales compuestos C/SiC para aplicaciones estructurales de alta temperatura. Parte II: Sistemas de protección contra la oxidación

Aparicio¹,

Durán²

2001

Bol. Soc. Esp. Ceram. Vidr.

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La utilizaci-n de los materiales compuestos C/SiC en aplicaciones estructurales a alta temperatura est ‡ limitada por la elevada velocidad de oxidaci-n de la fibra de carbono a temperaturas superiores de 450¼C. En esta segunda parte del trabajo se realiza una revisi-n de las posibilidades de protecci-n contra la oxidaci-n de estos materiales, incluyendo inhibidores, modificaci-n superficial del material compuesto, recubrimientos e infiltraci-n previa del sustrato. La eficacia de los inhibidores de la reacci-n de oxidaci-n est ‡ restringida a temperaturas de hasta 850¼C, mientras que la modificaci-n superficial del material compuesto da lugar a capas delgadas y poco resistentes a los ciclos tŽrmicos. En cambio, los recubrimientos son el mŽto-do m ‡s empleado porque permiten combinar composiciones y espesores de capa muy variados. La estructura multicapa es especialmente interesante en el caso de aplicaciones con intervalos de temperatura de trabajo amplios y cuando el material va a estar sometido a choques tŽrmicos. La infiltraci-n de la porosidad del sustrato s-lo mejora ligeramente la resistencia a la oxidaci-n del material compuesto C/SiC al reducir los caminos de acceso del ox'geno a las fibras de carbono. Sin embargo, la infiltraci-n complementa en gran medida las propiedades antioxidantes de los recubrimientos en el intervalo de bajas temperaturas, ya que Žstos suelen presentar fisuras abiertas por diferencias de dilataci-n tŽrmica con el sustrato. Palabras clave: C/SiC, materiales compuestos, protecci-n antioxidante C/SiC composites for high temperature structural applications. Part II: Oxidation protection systemsThe fact which currently excludes the use of C/SiC composites in high temperature structural applications is the high oxidation rate of carbon fibres at temperatures higher than 450¼C. In this second part of the paper, a review of the different oxidation protection systems, including inhibitors, surface modification of composites, coatings and previous infiltration of the substrates, has been carried out. The addition of inhibitors reduces the oxidation rate, but only up to 850¼C, while the surface modification of composites leads to thin coatings with poor thermal shock resistance. On the other hand, the external layers are the most usual method employed because allows combining different compositions and thicknesses. The multilayer coatings are especially interesting in applications with wide temperature range and thermal shocks requirements. The infiltration of substrate porosity improves slightly the oxidation resistance of C/SiC composites reducing the oxygen accessibility to carbon fibres. However, the infiltration complements very well the oxidation protection performance of a coating system at low temperature, since these normally present open cracks due to mismatch between coating and substrate thermal expansion coefficients. Keywords: C/SiC, composites, oxidation protection 1.-INTRODUCCIîNLas importantes propiedades de los materiales compuestos C/SiC, propiedades mec ‡nicas a alta tempe...

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Section: -Infiltraciîn De La Porosidad Residualunclassified

Materiales compuestos C/SiC para aplicaciones estructurales de alta temperatura. Parte II: Sistemas de protección contra la oxidación

Aparicio¹,

Durán²

2001

Bol. Soc. Esp. Ceram. Vidr.

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“…Whereas isothermal–isobaric CVI can efficiently produce thin‐wall cylindrical or tubular parts, it requires an extremely long time to produce thicker‐wall materials or plate‐shaped parts. To produce C/C composites in a much shorter time has been the hotspot of study for a long time, such as thermal‐gradient CVI, pressure‐gradient CVI, pulse‐CVI, electrically coupled CVI, and boiling film technique . But most of the improved methods are confined to research laboratories.…”

Section: Introductionmentioning

confidence: 99%

Rapid Densification of Carbon/Carbon Composites Plate by Pressure‐Gradient Chemical Vapor Infiltration

Huang

Zhang

et al. 2016

Adv Eng Mater

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Carbon/carbon (C/C) composites plate is prepared in the temperature range 1 223-1 373 K by improved pressure-gradient chemical vapor infiltration (CVI). The bulk densities and pore distributions of C/C composites after different infiltration period are measured and the densification kinetics is investigated. The results show that C/C composites plate with 300 Â 300 Â 15 mm is able to be densified to 1.52 g cm À3 within 60 h by pressure-gradient CVI. The porosity of pores with a size larger than 60 mm reduces markedly and the large pores are able to be filled more effectively by pressure-gradient CVI. The densification kinetics depends on the temperature and competition between reaction and convection mass transport. The activation energy is about 366 kJ mol -1 at 1 223-1 313 K and 43.2 kJ mol À1 above 1 313 K.

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“…9 Among these methods the most investigated are Si liquid infiltration, [10][11][12][13][14][15] Si gas infiltration, 10,16,17 SiO vapor infiltration, 16,18 polymer infiltration 19 and, the method used in this paper, chemical vapor infiltration and reaction (CVI-R) technique. 6,7,[20][21][22][23] Earlier investigations have been performed by Greil et al 7 on SiC ceramics derived from wood templates to compare three different ceramization methods. In that study the biaxial tensile loading condition perpendicular to the cell elongation has been measured and compared between the SiC ceramics obtained by Si melt infiltration, SiO vapor infiltration and CVI-R technique.…”

Section: Introductionmentioning

confidence: 99%

Application of the chemical vapor infiltration and reaction (CVI-R) technique for the preparation of highly porous biomorphic SiC ceramics derived from paper

Streitwieser

Popovska

Gerhard

et al. 2005

Journal of the European Ceramic Society

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Pressure-pulsed chemical vapour infiltration of SiC to porous carbon from a gas system SiCl4-CH4-H2

Cited by 17 publications

References 10 publications

Materiales compuestos C/SiC para aplicaciones estructurales de alta temperatura. Parte II: Sistemas de protección contra la oxidación

Materiales compuestos C/SiC para aplicaciones estructurales de alta temperatura. Parte II: Sistemas de protección contra la oxidación

Rapid Densification of Carbon/Carbon Composites Plate by Pressure‐Gradient Chemical Vapor Infiltration

Application of the chemical vapor infiltration and reaction (CVI-R) technique for the preparation of highly porous biomorphic SiC ceramics derived from paper

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