Emissivity of Silicon Carbide Composites as a Function of Temperature and Microstructure

Layer Formation ◽

Microwave Assisted ◽

Sic Fiber ◽

Sic Composites

ABSTRACTSpectral emissivity normal to the sample surface was investigated as a potential intelligent control parameter for the manufacture of SiC fiber reinforced SiC composites by chemical vapor infiltration (CVI) and microwave assisted CVI. Results indicated that at temperatures between 600 and 1000°C and wavelengths between 1500 and 2100 nm emissivity was sensitive to the sample porosity. It also appeared to be sensitive to the thickness of the oxide layer on the composites. The emissivity was not very sensitive to temperature in this region. It was concluded that emissivity is promising as a probe of density during manufacturing. It may also be useful as a probe of oxide layer formation.

Complex Permittivity of 3D Textile SiC/C/SiC Composites Fabricated by Chemical Vapor Infiltration at X-Band Frequency

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.368-372.1028 ◽

2008 ◽

Vol 368-372 ◽

pp. 1028-1030 ◽

Cited By ~ 1

Author(s):

Dong Lin Zhao ◽

Hong Feng Yin ◽

Yong Dong Xu ◽

Fa Luo ◽

Wan Cheng Zhou

Keyword(s):

Complex Permittivity ◽

Three Dimensional ◽

Chemical Vapor ◽

Pyrolytic Carbon ◽

Band Frequency ◽

Sic Fiber ◽

X Band ◽

Sic Composites ◽

Three-dimensional textile SiC fiber reinforced SiC composites with pyrolytic carbon interfacial layer (3D-SiC/C/SiC) were fabricated by chemical vapor infiltration. The microstructure and complex permittivity of the 3D textile SiC/C/SiC composites were investigated. The flexural strength of the 3D textile SiC/C/SiC composites was 860 MPa at room temperature. The real part (ε′) and imaginary part (ε″) of the complex permittivity of the 3D-SiC/C/SiC composites are 9.11~10.03 and 4.11~4.49, respectively at the X-band frequency. The 3D-SiC/C/SiC composites would be a good candidate for structural microwave absorbing material.

X-Ray Tomographic Microscopy of Nicalon Preforms and Chemical Vapor Infiltrated Nicalon/Silicon Carbide Composites

MRS Proceedings ◽

10.1557/proc-250-215 ◽

1991 ◽

Vol 250 ◽

Cited By ~ 4

Author(s):

M. D. Butts ◽

S. R. Stock ◽

J. H. Kinney ◽

T. L. Starr ◽

M. C. Nichols ◽

...

Keyword(s):

Three Dimensional ◽

Chemical Vapor ◽

High Resolution Computed Tomography ◽

X Ray ◽

Sic Fiber ◽

Sic Composites ◽

And Control ◽

Fiber Preforms ◽

Very High

AbstractFollowing the evolving microstructure of composites through all stages of chemical vapor infiltration (CVI) is a key to improved understanding and control of the process. X-ray Tomographic Microscopy (XTM), i.e., very high resolution computed tomography, allows the microstructure of macroscopic volumes of a composite to be imaged nondestructively with resolution approaching one micrometer. Results obtained with XTM on dense SiC/SiC composites and on woven SiC fiber preforms illustrate how details of the densification process can be followed using this technique during interruptions in processing. Ways in which the three-dimensional microstructural information may be used to improve modeling are also indicated.

Microstructures, Strength and Toughness of 2D Cf/(C-SiC) Composites by Chemical Vapor Infiltration

Journal of Inorganic Materials ◽

10.3724/sp.j.1077.2009.00939 ◽

2009 ◽

Vol 24 (5) ◽

pp. 939-942 ◽

Cited By ~ 1

Author(s):

Zhi-Xin MENG ◽

Lai-Fei CHENG ◽

Li-Tong ZHANG ◽

Yong-Dong XU ◽

Xiu-Feng HAN

Keyword(s):

Chemical Vapor ◽

Sic Composites ◽

Strength And Toughness ◽

Microwave assisted chemical vapor infiltration for the rapid fabrication of carbon/carbon composites

Carbon ◽

10.1016/j.carbon.2009.03.013 ◽

2009 ◽

Vol 47 (8) ◽

pp. 2144

Author(s):

Xie-Rong Zeng ◽

Ji-Zhao Zou ◽

Hai-Xia Qian ◽

Xin-Bo Xiong ◽

Xiao-Hua Li ◽

...

Keyword(s):

Chemical Vapor ◽

Carbon Composites ◽

Microwave Assisted ◽

Rapid Fabrication ◽

Ring compression properties of SiCf/SiC composites prepared by chemical vapor infiltration

Ceramics International ◽

10.1016/j.ceramint.2018.09.024 ◽

2018 ◽

Vol 44 (18) ◽

pp. 22529-22537

Author(s):

Yue Li ◽

Zhaoke Chen ◽

Ruiqian Zhang ◽

Zongbei He ◽

Haoran Wang ◽

...

Keyword(s):

Chemical Vapor ◽

Compression Properties ◽

Ring Compression ◽

Sic Composites ◽

MATHEMATICAL MODELING OF MICROWAVE-ASSISTED CHEMICAL VAPOR INFILTRATION FOR THE PRODUCTION OF CERAMIC–CERAMIC COMPOSITES

Computer Aided Innovation of New Materials ◽

10.1016/b978-0-444-88864-8.50114-x ◽

1991 ◽

pp. 531-536

Author(s):

J.W. EVANS ◽

D. GUPTA

Keyword(s):

Mathematical Modeling ◽

Chemical Vapor ◽

Ceramic Composites ◽

Microwave Assisted ◽

Effect of Interfacial Strength of SiC/SiC Composites Fabricated by Hot-Pressing and Chemical Vapor Infiltration Method on their Mechanical Properties

Fusion Technology ◽

10.13182/fst01-a11963304 ◽

2001 ◽

Vol 39 (2P2) ◽

pp. 607-611 ◽

Cited By ~ 1

Author(s):

Katsumi Yoshida ◽

Toyohiko Yano ◽

Takayoshi Iseki

Keyword(s):

Mechanical Properties ◽

Hot Pressing ◽

Interfacial Strength ◽

Chemical Vapor ◽

Sic Composites ◽

Infiltration Method ◽

High toughness, 3D textile, SiC/SiC composites by chemical vapor infiltration

Materials Science and Engineering A ◽

10.1016/s0921-5093(01)01303-x ◽

2001 ◽

Vol 318 (1-2) ◽

pp. 183-188 ◽

Cited By ~ 28

Author(s):

Yongdong Xu ◽

Laifei Cheng ◽

Litong Zhang ◽

Hongfeng Yin ◽

Xiaowei Yin

Keyword(s):

Chemical Vapor ◽

High Toughness ◽

Sic Composites ◽

The Stability of BN Interfacial Coatings in CFCC Systems During Oxidation and Exposure to Moisture

Microscopy and Microanalysis ◽

10.1017/s1431927600010539 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 729-730

Author(s):

K.S. Ailey ◽

K.L. More ◽

R.A. Lowden

Keyword(s):

Elevated Temperatures ◽

Impurity Content ◽

Chemical Vapor ◽

Ceramic Matrix Composites ◽

Forced Flow ◽

Crystallographic Structure ◽

Matrix Composites ◽

Sic Composites ◽

The Stability

The mechanical reliability of ceramic matrix composites (CMCs) at elevated temperatures in oxidative environments is primarily dependent upon the chemical and structural stability of the fiber/matrix interface. Graphitic carbon coatings have traditionally been used to control the interfacial properties in CMCs, however, their use is limited in high temperature oxidative environments due to the loss of carbon and subsequent oxidation of the fiber and matrix. Thus, BN is being investigated as an alternative interfacial coating since it has comparable room temperature properties to carbon with improved oxidation resistance. The stability of BN interfaces in SiC/SiC composites is being investigated at elevated temperatures in either flowing oxygen or environments containing water vapor. The effect of several factors on BN stability, including crystallographic structure, extent of BN crystallization, and impurity content, are being evaluated.Nicalon™ fiber preforms were coated with ≈ 0.4 μm of BN by CVD using BCl3, NH3, and H2 at 1373 K. The coated preforms were densified using a forced-flow chemical vapor infiltration (FCVI) technique developed at ORNL.

Microstructure, mechanical properties and oxidation resistance of SiCf/SiC composites incorporated with boron nitride nanotubes

RSC Advances ◽

10.1039/c6ra16496j ◽

2016 ◽

Vol 6 (86) ◽

pp. 83482-83492 ◽

Cited By ~ 7

Author(s):

Guangxiang Zhu ◽

Shaoming Dong ◽

Dewei Ni ◽

Chengying Xu ◽

Dengke Wang

Keyword(s):

Mechanical Properties ◽

Chemical Vapor ◽

Boron Nitride Nanotubes ◽

Raw Material ◽

Boron Powder ◽

Hierarchical Composites ◽

Sic Composites ◽

Polymer Impregnation

SiCf/BNNTs–SiC hierarchical composites were fabricated via firstly in situ growth of BNNTs on SiC fibers using boron powder as a raw material and then matrix densification by chemical vapor infiltration and polymer impregnation/pyrolysis methods.