Preparation and Microstructure Characterizations of Novel C/C-Zr(Hf)B2-Zr(Hf)C-SiC Composites

2014 ◽  
Vol 788 ◽  
pp. 593-597 ◽  
Author(s):  
Jie Wen Li ◽  
Xi Wei ◽  
Wei Gang Zhang ◽  
Min Ge
Keyword(s):  
High Temperature ◽  
Chemical Vapor ◽  
Pyrolytic Carbon ◽  
Carbon Composite ◽  
Chemical Vapor Infiltration ◽  
Polymeric Precursors ◽  
Ultra High Temperature Ceramics ◽  
Sic Composites ◽  
Fiber Preforms ◽  
Very High

A series of novel C/C-Zr (Hf)B2-Zr (Hf)C-SiC composites were prepared by chemical vapor infiltration (CVI) of pyrolytic carbon and polymeric impregnation and pyrolysis (PIP) with hybrid polymeric precursors of SiC (polycarbosilane), Zr (Hf)C and Zr (Hf)B2 in carbon fiber preforms. The formed ultra-high temperature ceramics (UHTCs) matrix of SiC-ZrC-ZrB2 and SiC-HfC-HfB2 were designed to improve the oxidation resistance of carbon/carbon composite at very high temperatures above 2000°C. The pyrolysis process of Zr (Hf)C and Zr (Hf)B2 polymeric precursors was investigated, and the results showed that the hybrid precursors could be successfully transformed into Zr (Hf)C and Zr (Hf)B2 ceramic particles with the sizes of nanometer with temperatures above 1500°C. Furthermore, the multiscale structure of C/C-Zr (Hf)B2-Zr (Hf)C-SiC composites were also characterized , showing that the carbon fibers were covered by pyrolytic carbon, and the continuous ceramic matrix was well dispersed, formed by Zr (Hf)C and Zr (Hf)B2 nanoparticles distributing homogeneously in the continuous SiC matrix. This homogeneous dispersion of composite ceramics of Zr (Hf)C and Zr (Hf)B2 with SiC plays excellent protection of C/C composites from oxidation at high temperature via formation of stable oxides coatings.

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

1991 ◽  
Vol 250 ◽  
Author(s):  
M. D. Butts ◽  
S. R. Stock ◽  
J. H. Kinney ◽  
T. L. Starr ◽  
M. C. Nichols ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Chemical Vapor ◽  
Chemical Vapor Infiltration ◽  
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.

Fatigue of Advanced SiC/SiC Ceramic Matrix Composites at Elevated Temperature in Air and in Steam

2018 ◽  
Author(s):  
M. B. Ruggles-Wrenn ◽  
N. J. Boucher ◽  
C. P. Przybyla
Keyword(s):  
High Temperature ◽  
Chemical Vapor ◽  
Ceramic Matrix Composites ◽  
Pyrolytic Carbon ◽  
Ceramic Composites ◽  
Chemical Vapor Infiltration ◽  
Fatigue Performance ◽  
High Temperature Mechanical Properties ◽  
Sic Ceramic ◽  
Fiber Preforms

High-temperature mechanical properties and tension-tension fatigue of three SiC/SiC ceramic composites are discussed. Effects of steam on high-temperature fatigue are evaluated. The three composites consist of a SiC matrix reinforced with SiC (Hi-Nicalon™) fibers. Composite 1 was processed by chemical vapor infiltration (CVI) of SiC into fiber preforms coated with BN. Composite 2 had an oxidation inhibited matrix consisting of alternating SiC and B4C layers and was processed by CVI. Fiber preforms were coated with pyrolytic carbon with B4C overlay. Composite 3 had a melt-infiltrated (MI) matrix consolidated by combining CVI-SiC with SiC particulate slurry and molten Si infiltration. Fiber preforms were coated with BN. Tension-tension fatigue was investigated at 1200°C in air and in steam. Steam significantly degraded the fatigue performance of composites 1 and 3, but had little influence on the fatigue performance of composite 2. Composite microstructure, as well as damage and failure mechanisms were investigated.

C/C-ZrB2-ZrC-SiC Composites Derived from Polymeric Precursor Infiltration and Pyrolysis Part I

2013 ◽  
pp. 413-434 ◽  
Author(s):  
Weigang Zhang ◽  
Changming Xie ◽  
Min Ge ◽  
Xi Wei
Keyword(s):  
Carbon Fiber ◽  
Interface Reaction ◽  
Fiber Surface ◽  
Pyrolytic Carbon ◽  
Polymeric Precursors ◽  
Ultra High Temperature Ceramics ◽  
Molar Ratios ◽  
Barrier Coating ◽  
Ceramic Precursors ◽  
Sic Composites

Two-dimensional C/C-ZrB2-ZrC-SiC composites with three phases of ultra high temperature ceramics (UHTCs) are fabricated for the first time using blending pre-ceramic polymeric precursors through the traditional polymer infiltration and pyrolysis (PIP) technique, in which a porous carbon fiber reinforced pyrolytic carbon (C/C) with a porosity of about 60% is prepared as preforms. The fabricated composite possesses a matrix of 20ZrB2-30ZrC-50SiC, which is obtained by co-pyrolysis of three pre-ceramic polymers solution in xylene with certain molar ratios. Pyrolysis of these ZrB2-ZrC-SiC pre-ceramic precursors is studied with XRD characterization of the residual solids. The gas phase products are analysized with an on-line GC-MS-FTIR coupling technique, which confirms the formation of crystalline ZrC and ZrB2 from these precursors at temperatures above 1400°C. Possible mechanisms of pyrolysis and formation of pure ZrB2 from the precursors with various B/Zr molar ratios are suggested. The densification process and microstructures of the fabricated composite are studied. It is found that a composite with a bulk density of 2.06 g/cm3 and open porosity of 9.6% can be obtained after 16 PIP cycles. The formed matrix exhibits homogeneous dispersion of three matrix ceramics without any oxide impurities, i.e., the nano sized ZrB2 and ZrC particles dispersed in a continuous SiC ceramic with clean crystalline boundaries and particle dimensions less than 200 nm. No erosion or interface reaction occurs upon the carbon fiber reinforcement, which therefore avoids a dramatic deterioration of mechanical strength of carbon fiber and the composite. Improvement of PIP benefits from two aspects; firstly, the dense pyrolytic carbon interphase deposited on fiber surface by CVI serves as barrier coating and secondly, pyrolysis of the novel organic polymeric precursors does not release corrosive by-products such as hydrogen chloride.

C/C-ZrB2-ZrC-SiC Composites Derived from Polymeric Precursor Infiltration and Pyrolysis Part I

2014 ◽  
pp. 430-446
Author(s):  
Weigang Zhang ◽  
Changming Xie ◽  
Min Ge ◽  
Xi Wei
Keyword(s):  
Carbon Fiber ◽  
Interface Reaction ◽  
Fiber Surface ◽  
Pyrolytic Carbon ◽  
Polymeric Precursors ◽  
Ultra High Temperature Ceramics ◽  
Molar Ratios ◽  
Barrier Coating ◽  
Ceramic Precursors ◽  
Sic Composites

Two-dimensional C/C-ZrB2-ZrC-SiC composites with three phases of ultra high temperature ceramics (UHTCs) are fabricated for the first time using blending pre-ceramic polymeric precursors through the traditional polymer infiltration and pyrolysis (PIP) technique, in which a porous carbon fiber reinforced pyrolytic carbon (C/C) with a porosity of about 60% is prepared as preforms. The fabricated composite possesses a matrix of 20ZrB2-30ZrC-50SiC, which is obtained by co-pyrolysis of three pre-ceramic polymers solution in xylene with certain molar ratios. Pyrolysis of these ZrB2-ZrC-SiC pre-ceramic precursors is studied with XRD characterization of the residual solids. The gas phase products are analysized with an on-line GC-MS-FTIR coupling technique, which confirms the formation of crystalline ZrC and ZrB2 from these precursors at temperatures above 1400°C. Possible mechanisms of pyrolysis and formation of pure ZrB2 from the precursors with various B/Zr molar ratios are suggested. The densification process and microstructures of the fabricated composite are studied. It is found that a composite with a bulk density of 2.06 g/cm3 and open porosity of 9.6% can be obtained after 16 PIP cycles. The formed matrix exhibits homogeneous dispersion of three matrix ceramics without any oxide impurities, i.e., the nano sized ZrB2 and ZrC particles dispersed in a continuous SiC ceramic with clean crystalline boundaries and particle dimensions less than 200 nm. No erosion or interface reaction occurs upon the carbon fiber reinforcement, which therefore avoids a dramatic deterioration of mechanical strength of carbon fiber and the composite. Improvement of PIP benefits from two aspects; firstly, the dense pyrolytic carbon interphase deposited on fiber surface by CVI serves as barrier coating and secondly, pyrolysis of the novel organic polymeric precursors does not release corrosive by-products such as hydrogen chloride.

Microstructure and Mechanical Property of 3D Textile C/SiC Composites Fabricated by Chemical Vapor Infiltration

2006 ◽  
Vol 11-12 ◽  
pp. 81-84 ◽  
Author(s):  
Dong Lin Zhao ◽  
Hong Feng Yin ◽  
Fa Luo ◽  
Wan Cheng Zhou
Keyword(s):  
Mechanical Property ◽  
Silicon Carbide ◽  
Carbon Fiber ◽  
Interfacial Layer ◽  
Chemical Vapor ◽  
Pyrolytic Carbon ◽  
Chemical Vapor Infiltration ◽  
Sic Composites ◽  
Microstructure And Mechanical Property ◽  
Vapor Infiltration

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.

Microstructure and high temperature strength of SiCW/SiC composites by chemical vapor infiltration

2010 ◽  
Vol 527 (21-22) ◽  
pp. 5592-5595 ◽  
Author(s):  
Yunfeng Hua ◽  
Litong Zhang ◽  
Laifei Cheng ◽  
Zhengxian Li ◽  
Jihong Du
Keyword(s):  
High Temperature ◽  
Chemical Vapor ◽  
Chemical Vapor Infiltration ◽  
High Temperature Strength ◽  
Sic Composites ◽  
Vapor Infiltration

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

2008 ◽  
Vol 368-372 ◽  
pp. 1028-1030 ◽  
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 ◽  
Chemical Vapor Infiltration ◽  
Band Frequency ◽  
Sic Fiber ◽  
X Band ◽  
Sic Composites ◽  
Vapor Infiltration

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.

Preparation and Assessment of C/C-ZrB2-SiC Ultra-High Temperature Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 719-722 ◽  
Author(s):  
Jie Fan ◽  
Chang Ling Zhou ◽  
Chong Hai Wang ◽  
Yan Yan Wang ◽  
Rui Xiang Liu
Keyword(s):  
High Temperature ◽  
Carbon Fiber ◽  
Thermal Protection ◽  
Chemical Vapor ◽  
Pyrolytic Carbon ◽  
Composite Ceramic ◽  
Chemical Vapor Infiltration ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced ◽  
Ultra High Temperature

With the background of thermal protection applications of anti-oxidation carbon fiber reinforced composites, carbon fiber reinforced ultra-high temperatureceramics with homogeneous disperse complex matrix of C-ZrB2-SiC (C/C-ZrB2-SiC) was prepared. Carbon fiber performs were deposited with pyrolytic carbon by chemical vapor infiltration method. Subsequently, the composite precursors were prepared by completely mutually dissolving of ZrB2 polymeric precursor and polycarbosilane dimethylbenzene solution. Then the nano-dispersed ZrB2-SiC composite ceramic was introduced into the C/C preforms by polymer impregnant and pyrolysis process. The C/C-ZrB2-SiC composite shows excellent ablation behavior with the ablating rate of 8*10-4mm/s. The microstructural and compositional characterizations of the C/C-ZrB2-SiC composites indicates that ZrB2 nanoparticle is distributed homogeneously in the continuous SiC phase, which is beneficial to enhance ultra-high temperature ablation resistance of the composites.

scholarly journals Effect of pyrolytic carbon interphase on mechanical properties of mini T800-C/SiC composites

2021 ◽  
Author(s):  
Donglin Zhao ◽  
Tong Guo ◽  
Xiaomeng Fan ◽  
Chao Chen ◽  
Yue Ma
Keyword(s):  
Mechanical Properties ◽  
Weibull Modulus ◽  
Chemical Vapor ◽  
Pyrolytic Carbon ◽  
Chemical Vapor Infiltration ◽  
Matrix Composites ◽  
Average Strength ◽  
Gas Source ◽  
Maximum Value ◽  
Sic Composites

AbstractThe effect of pyrolytic carbon (PyC) thickness on the tensile property of mini T800 carbon fiber reinforced SiC matrix composites (C/SiC) was studied. PyC interphase was prepared by chemical vapor infiltration (CVI) process using C3H6–Ar as gas source, the PyC thickness was adjusted from 0 to 400 nm, and then the SiC matrix was prepared by CVI process using methyltrichlorosilane (MTS)–H2–Ar as precursor and gas source. The results showed that the tensile strength of mini T800-C/SiC increased first and then decreased with the increase of the PyC thickness. When the thickness of PyC was 100 nm, the average strength reached the maximum value of 393 ± 70 MPa. The Weibull modulus increased from 2.0 to 8.06 with the increase of PyC thickness, and the larger the Weibull modulus, the smaller the dispersion, which indicated that the regulation of PyC thickness was conducive to improve tensile properties.

scholarly journals Effect of Pyrolytic Carbon Interphase on Mechanical Properties of mini T800-C/SiC Composites

2020 ◽  
Author(s):  
Donglin Zhao ◽  
Tong Guo ◽  
X.M. Fan ◽  
Chao Chen ◽  
Yue Ma
Keyword(s):  
Mechanical Properties ◽  
Weibull Modulus ◽  
Chemical Vapor ◽  
Pyrolytic Carbon ◽  
Chemical Vapor Infiltration ◽  
Matrix Composites ◽  
Average Strength ◽  
Gas Source ◽  
Maximum Value ◽  
Sic Composites

Abstract The effect of pyrolytic carbon (PyC) thickness on the tensile property of mini T800-carbon fiber reinforced SiC matrix composites (mini-C/SiC) was studied in this work. PyC interphase was prepared by chemical vapor infiltration (CVI) process using C3H6-Ar as gas source, and the PyC thickness was adjusted from 0 to 400 nm, then the SiC matrix was prepared by CVI process using methyltrichlorosilane (MTS)-H2-Ar as precursor and gas source. The results showed that the tensile strength of mini-C/SiC increased first and then decreased with the increase of the PyC thickness. When the thickness of PyC was 100 nm, the average strength reached the maximum value of 393±70 MPa. The Weibull modulus increased from 2.0 to 8.06 with the increase of PyC thickness, the larger the Weibull modulus, the smaller the dispersion, which indicated that the regulation of PyC thickness is conducive to improve tensile properties.

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