Oxidation protection in carbon-carbon composites

Jawed, I.; Nagle, Dennis C.

doi:10.1016/0025-5408(86)90075-9

Cited by 27 publications

(9 citation statements)

References 10 publications

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“…Since the mass gain in the first stage was only slight, the thin layer of SiO 2 might be formed on the surface of Al 4 SiC 4 particles, i.e., the mass gain with the slight oxidation of Al 4 (5) Figure 6 shows the SEM micrographs of Al 4 SiC 4 before and after oxidation at 1600°C. In the first stage of the oxidation in the temperature range from 350 to 850°C, oxygen diffusing to the surfaces of Al 4 SiC 4 may react quickly with the surface of Al 4 SiC 4 particles, suggesting the formation of amorphous SiO 2 .…”

Section: B Formation Process Of Al 4 Sicmentioning

confidence: 99%

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Preparation and oxidation of Al₄SiC₄

2002

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Single-phase Al 4 SiC 4 was successfully synthesized by heating the powder mixture of aluminum, silicon, and carbon black in the molar ratio corresponding to the chemical composition of Al 4 SiC 4 with a small amount of triethanolamine (TEA) above 1200°C in argon gas. Without TEA, two phases of Al 4 C 3 and SiC were formed, irrespective of the heating temperature. The marked mass gain by oxidation of Al 4 SiC 4 was observed with forming Al 2 O 3 and SiO 2 in the range of 850 to 1150°C, which slightly increased above 1150°C. At 1600°C, mullite was formed by the reaction between Al 2 O 3 and SiO 2 .

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Section: B Formation Process Of Al 4 Sicmentioning

confidence: 99%

“…[3][4][5][6][7][8][9][10] In these methods, the improvement of oxidation resistance is supposed to be due to the protective oxide layer on the surface of composites. [3][4][5][6][7][8][9][10] In these methods, the improvement of oxidation resistance is supposed to be due to the protective oxide layer on the surface of composites.…”

Section: Introductionmentioning

confidence: 99%

Preparation and oxidation of Al₄SiC₄

2002

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“…According to the chemical composition, these clayey materials are characterized by high iron contents whose the effect on the color of the ceramic materials is well known, and the attendance of fluxing agents as alkali and alkaline earth elements which are necessary for low temperatures firing. Mineralogically, considered materials consist entirely of kaolinite rich clays containing impurities, mostly illite, calcite, feldspar, and iron, which serve as fluxing agents to improve densification at low temperature [3][4][5][6] and appeared helpful in improving the physical and mechanical properties of the manufactured ceramic materials. These materials can be used for ceramic production that they have appropriate chemical and mineralogical compositions composed of kaolinite and illite often contain various impurities including SiO 2 , CaO, Fe 2 O 3 , and alkali, certainly that are advantageous for its workability, moulding, drying behavior, firing behavior, and quality of the ceramic products like mechanical strength and porosity.…”

Section: Characterization Of Compositesmentioning

confidence: 99%

Synthesis and characterization of carbon–silicon carbide particulate composites by powder metallurgical route

Manocha

Prasad

Manocha

2021

Int J Applied Ceramic Tech

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Carbon and graphite materials have remarkable characteristics of withstanding high temperatures up to 3000°C in protective environment, good thermal shock resistance, low coefficient of thermal expansion, good thermal and electrical conductivities, low density, etc. These properties make them strong candidates to be used in general high temperature engineering applications. 1,2 However, there are disadvantages such as low strength as compared to various ceramic materials and their limited use in an oxidizing atmosphere above 450°C. Carbon and Graphite materials have low friction values as well. Various techniques have been tried to overcome these problems. These are coating the carbon surface with borates or borosilicates or incorporating different carbides into carbon materials which can increase the oxidation resistance temperature to about 900-1000°C and also decrease wear. 3--6 The development of carbon-ceramic particulate composites is another way to overcome these disadvantages. The incorporation of different ceramics into carbon results in significant improvement in mechanical properties, especially hardness and bending strength, in addition to enhancement of oxidation resistance of the carbon-ceramic composites. 7 Many efforts have been made to prepare carbon-ceramic composites with silicon powder and phenolic resin as carbon precursor. Tang et al 8 reported a three-step process in which silicon powder and phenolic resin were used as raw materials to fabricate silicon carbide powder via coat-mix process. They obtained silicon carbide powders of particle size varying from 0.1 to 0.4 μm with mean particle size of

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“…Las mezclas realizadas con ZrB 2 , B, SiB 4 , tetraetilortosilicato (TEOS) y tributilfosfato, originan diferentes vidrios del sistema P-Si-B-O que mejoran sensiblemente la resistencia a la oxidaci-n. La aplicaci-n de un tratamiento con H 3 PO 4 previamente a la infiltraci-n de los inhibidores mejora la resistencia a la oxidaci-n. El efecto del ‡cido se centra en la eliminaci-n de diferentes catalizadores (Na, K y Ca) de la oxidaci-n del carbono (5,6).El empleo de TiO 2 y/o ZrO 2 puede tambiŽn inhibir la oxidaci-n del grafito, ya que ambos -xidos donan electrones al grafito estabilizando su estructura (7).…”

Section: -Inhibidoresunclassified

“…El difenilborosilano permite disponer de diferentes relaciones Si/B que modifican las propiedades mec ‡ni-cas y antioxidativas del material compuesto: al aumentar el porcentaje de silicio mejoran las propiedades mec ‡nicas del material pero se reduce la resistencia contra la oxidaci-n a bajas temperaturas, debido a que la proporci-n de B 2 O 3 generado es menor. En un an ‡lisis termogravimŽtrico hasta 1000¼C en aire se muestra que el porcentaje de fibra de carbono remanente despuŽs del ensayo fue de 15, 38 y 50%, para relaciones Si/B de 3/1, 3/2 y 3/3, respectivamente (6,88). Para protecci-n a temperaturas aoen menores puede emplearse -xido de boro puro (2).…”

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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Oxidation protection in carbon-carbon composites

Cited by 27 publications

References 10 publications

Preparation and oxidation of Al₄SiC₄

Preparation and oxidation of Al₄SiC₄

Synthesis and characterization of carbon–silicon carbide particulate composites by powder metallurgical route

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

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Oxidation protection in carbon-carbon composites

Cited by 27 publications

References 10 publications

Preparation and oxidation of Al4SiC4

Preparation and oxidation of Al4SiC4

Synthesis and characterization of carbon–silicon carbide particulate composites by powder metallurgical route

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

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Preparation and oxidation of Al₄SiC₄

Preparation and oxidation of Al₄SiC₄