Radiation stable, hybrid, chemical vapor infiltration/preceramic polymer joining of silicon carbide components

Three dimensional textile carbon fiber reinforced silicon carbide (3D textile C/SiC) composites with pyrolytic carbon interfacial layer were fabricated by chemical vapor infiltration. The microstructure and mechanical property of 3D textile C/SiC composites were investigated. A thin pyrolysis carbon layer (0.2 ± μm) was firstly deposited on the surface of carbon fiber as the interfacial layer with C3H6 at 850°C and 0.1 MPa. Methyltrichlorosilane (CH3SiCl3 or MTS) was used for the deposition of the silicon carbide matrix. The conditions used for SiC deposition were 1100°C, a hydrogen to MTS ratio of 10 and a pressure of 0.1 MPa. The density of the composites was 2.1 g cm-3. The flexural strength of the 3D textile C/SiC composites was 438 MPa. The 3D textile C/SiC composites with pyrolytic carbon interfacial layer exhibit good mechanical properties and a typical failure behavior involving fibers pull-out and brittle fracture of sub-bundle. The real part (ε′) and imaginary part (ε″) of the complex permittivity of the 3D-C/SiC composites are 51.53-52.44 and 41.18-42.08 respectively in the frequency range from 8.2 to 12.4 GHz. The 3D-C/SiC composites would be a good candidate for microwave absorber.

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A Numerical Study of Densification Behavior of Silicon Carbide Matrix Composites in Isothermal Chemical Vapor Infiltration

Journal of Wuhan University of Technology-Mater Sci Ed ◽

10.1007/s11595-018-1976-8 ◽

2018 ◽

Vol 33 (6) ◽

pp. 1365-1371 ◽

Cited By ~ 1

Author(s):

Kang Guan ◽

Jianqing Wu ◽

Laifei Cheng

Keyword(s):

Silicon Carbide ◽

Numerical Study ◽

Chemical Vapor ◽

Chemical Vapor Infiltration ◽

Matrix Composites ◽

Densification Behavior ◽

Carbide Matrix ◽

Silicon Carbide Matrix ◽

Vapor Infiltration

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Microstructure of Cf/SiC Composite with Precursor of Hexamethyldisilazane by Chemical Vapor Infiltration

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.1248 ◽

2007 ◽

Vol 336-338 ◽

pp. 1248-1250

Author(s):

Ming Yuan ◽

Zheng Ren Huang ◽

Shao Ming Dong ◽

Dong Liang Jiang

Keyword(s):

Silicon Carbide ◽

Chemical Vapor ◽

Carbon Layer ◽

Chemical Vapor Infiltration ◽

Forced Flow ◽

Precursor Material ◽

Reinforcing Fibers ◽

Polycrystalline Silicon Carbide ◽

The Matrix ◽

Vapor Infiltration

A method of waved-thermal field chemical vapor infiltration was introduced. And interphases of silicon carbide layer and carbon layer were processed via the route. The preforms with the interfacial coatings were densified by method of forced-flow thermal-gradient chemical vapor infiltration (FCVI) employing hexamethyldisilazane (HMDS) as precursor material of the matrix. The matrix of the composites annealed at 1400°C consists of nano-polycrystalline silicon carbide. The configuration of fracture surface was observed by scanning electronic microscopy (SEM). The interphases behaved successfully as mechanical fuse for the reinforcing fibers.

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