SiC composites, carbon fiber reinforced

Continuous carbon fiber reinforced SiC composites were prepared by Xu and Zhang [211] using CVI, in which the preforms were fabricated by the three dimensional braid method. For the composites with no interfadal layer, flexural strength and fracture toughness increased with the density of the composites and the maximum values were 520 MPa and 16.5 MPam , respectively. The fracture behavior was dependent on the interfacial bonding between fiber /matrix and fiber bundle/bundle, which was determined by the density of the composites. Heat treatment had a significant influence on the mechanical properties and fracture behavior. The composites with pyrolysis interfacial layers exhibited characteristic fracture and relatively low strength (300 MPa). 

Tani et al [214] prepared carbon fiber reinforced SiC composites by reaction bonding. 

Yttrium silieate (Y2SiOs) eoatings complement SiC coatings for protecting ceramic multilayer composite materials based on carbon fiber reinforced SiC composites (C-SiC). 

Tani and Shobu [256] fabricated unidirectional carbon fiber reinforced SiC composites with a polymer pyrolysed and reaction bonded SiC matrix. In spite of a low density of about 1.85 mgm , the flexural strength of the composites was about 530 MPa. Addition of polymer decreased the open porosity and increased the elastic modulus of the composites. 

SiC- Sic and SiC-C (Continuous Fiber-Reinforced SiC Matrix Composites) Three different processes are commonly used to manufacture carbon fiber-reinforced SiC materials (i) chemical vapor infiltration (CVI) [340] (ii) liquid polymer infiltration (LPI also termed polymer infiltration and pyrolysis, PIP) [341]) and (iii) melt infiltration or liquid silicon infiltration (MI/LSI) [342]. 

Ansorge [153] produced a carbon fiber reinforced SiC ceramic matrix composite by liquid phase infiltration of Si into a carbon-carbon composite. 

Silicon nitride has been reinforced by carbon [159] and Suzuki et al [160] have investigated fiber pullout mechanisms of carbon fiber reinforced SisN4 ceramic composites. Carbon fiber composites are stable in N2 at high temperatures [161,162]. At present, interest has been generated in SiC-SiC composites. Lundberg et al [163,164] successfully HIPed carbon fiber reinforced Si3N4 composites and Guo et al [165] used carbon fiber to reinforce Si3N4. Silicon nitride will react with carbon ... 

Three dimensional carbon fiber reinforced SiC and SisN4 composites were fabricated using repeated infiltration of organosilicon slurry under vacuum and pressure by Nakano et al [192]. The open porosity of the infiltrated body was reduced from 40% after the first infiltration to approximately 8% after the seventh cycle. Further porosity reduction to less than 3% was achieved by hot press densification. The maximum values of flexural strength and fracture toughness were 260 MPa and 7.3 MPam for C-Si3N4 composites, and 185 MPa and 6 MPam for C-SiC composite. 

Ostertag and Haug [194] also used filament winding to prepare carbon fiber reinforced SiC matrix composites using Si polymers as matrix precursors, which were pyrolyzed to form a SiC matrix. 

Carbon fiber reinforced SiC matrix composites suitable for use in hypersonie vehicles and liquid rocket nozzles were developed by the combined process of CVI and precursor impregnation and pyrolysis (PIP) [210]. The physical and mechanical properties of the... 

In the fabrication process of three dimensional carbon fiber reinforced SiC matrix composite, Suzuki and Nakano [207] applied PCVI as the final densification process for the specimen, which was made by the joint process of slurry infiltration and organosilicon polymer pyrolysis. The open porosity and bulk density of the specimen changed from 5.3% and 2.63 g-cm (relative density of 94%) to 3.5% and 2.67 g cm (relative density of 95%) by the apphcation of PCVI (1173 1223K, total 90,000 pulses). The flexural strength of the specimen increased over 20% (mean value =153 MPa, maximum value = 174 MPa). 

Unidirectional carbon fiber reinforced SiC/C composites were fabricated by Tani et al [213] using reaction bonding. The prepreg for the composites was prepared by the filament winding method, with a mixed slurry of phenolic resin, sihcon powder and ethyl alcohol, then die pressed at 130°C and sintered in Ar. The formation of SiC took place through a reaction between the carbon from the pyrolyzed phenolic resin and the silicon powder above a temperature of about 1320°C and was completed by 1420°C. The bulk density of the composites was about 1.7 gcm. The average flexural strength of the composites with a Si/C ratio of 0.2, 0.4 and 1 was about 310, 250 and 150 MPa respectively. 

Two dimensional woven carbon fiber reinforced SiC-C matrix composites have been produced by reaction bonding [215]. 

Kikuchi et al [220] determined the reactivities of carbon fibers in hot pressed carbon fiber reinforced SiC ceramic composite. 

Kikuchi S, Yasutomi Y, Arakawa H, Reactivities of carbon-fibers in hot-pressed carbon-fiber reinforced SiC ceramic composite, Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi—Journal of the Ceramic Society of Japan, 102(5), 456-461, 1994. 

Padmavathi, N., Ray, K. K., Subrahmanyam, J., Ghosal, R, Sweety Kumari. (2009). New-route to process uni-directional carbon fiber reinforced (SiC-fZrB ) matrix mini-composites. Journalof Materials Science, 44,3255-3264. doi 10.1007/ S10853-009-3437-4. 

Hatta, H., Aoki, T., Kogo, Y., Yarii, T., (1999), High-temperature oxidation behavior of SiC-coated carbon fiber-reinforced carbon matrix composites , Composites Part A, 30, 515-520. 

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