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.

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.

scholarly journals Chemical Vapor Infiltration of Non-Oxide Ceramic Matrix Composites

1993 ◽  
Vol 327 ◽  
Author(s):  
Theodore M. Besmann ◽  
David P. Stinton ◽  
Richard A. Lowden
Keyword(s):  
State Of The Art ◽  
Chemical Vapor ◽  
Ceramic Matrix Composites ◽  
Ceramic Composites ◽  
Chemical Vapor Infiltration ◽  
Oxide Ceramic ◽  
Matrix Composites ◽  
Aerospace Applications ◽  
Structural Applications ◽  
Vapor Infiltration

AbstractContinuous fiber ceramic composites are enabling new, high temperature structural applications. Chemical vapor infiltration methods for producing these composites are being investigated, with the complexity of filament weaves and deposition chemistry merged with standard heat and mass transport relationships. Silicon carbide-based materials are, by far, the most mature, and are already being used in aerospace applications. This paper addresses the state-of-the art of the technology and outlines current issues.

scholarly journals High-temperature Mechanical Properties and Their Influence Mechanisms of ZrC-Modified C-SiC Ceramic Matrix Composites up to 1600 °C

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1581 ◽  
Author(s):  
Jianjun Sha ◽  
Shouhao Wang ◽  
Jixiang Dai ◽  
Yufei Zu ◽  
Wenqiang Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Flexural Strength ◽  
Residual Stresses ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Thermally Induced ◽  
High Temperature Mechanical Properties ◽  
Sic Ceramic

In order to understand the influence of the mechanisms of ZrC nanoparticles on the high-temperature mechanical properties of C-SiC ceramic matrix composites, the mechanical properties were measured from room temperature (RT) to 1600 °C under vacuum. The microstructures features were characterized by scanning electron microscopy. In comparison with the composites without ZrC nanoparticles, the ZrC-modified composite presented better mechanical properties at all temperatures, indicating that the mechanical properties could be improved by the ZrC nanoparticles. The ZrC nanoparticles could reduce the residual silicon and improve the microstructure integrity of composite. Furthermore, the variation of flexural strength and the flexural modulus showed an asynchronous trend with the increase of temperature. The flexural strength reached the maximum value at 1200 °C, but the highest elastic modulus was obtained at 800 °C. The strength increase was ascribed to the decrease of the thermally-induced residual stresses. The degradation of mechanical properties was observed at 1600 °C because of the microstructure deterioration and the formation of strongly bonded fiber–matrix interface. Therefore, it is concluded that the high temperature mechanical properties under vacuum were related to the consisting phase, the matrix microstructure, and the thermally-induced residual stresses.

Advances in Modeling of the Chemical Vapor Infiltration Process

1991 ◽  
Vol 250 ◽  
Author(s):  
Thomas L. Starr
Keyword(s):  
Chemical Vapor ◽  
Ceramic Matrix Composites ◽  
Ceramic Composites ◽  
Chemical Vapor Infiltration ◽  
Forced Flow ◽  
Material Transport ◽  
Process Technology ◽  
Infiltration Process ◽  
Design And Manufacture ◽  
Vapor Infiltration

AbstractThe technology of chemical vapor infiltration (CVI) has progressed dramatically over the past twenty-five years and stands now as the leading process for fabrication of high temperature structures using ceramic matrix composites. Modeling techniques also have advanced from extensions of catalyst theory to full 3-D finite element code with provision for temperature and pressure gradients. These modeling efforts offer insight into critical factors in the CVI process, suggest opportunities for further advances in process technology and provide a tool for integrating the design and manufacture of advanced components.Early modeling identified the competition between reaction and diffusion in the CVI process and the resulting trade-off between densification rate and uniformity. Modeling of forced flow/thermal gradient CVI showed how the evolution of material transport properties provides a self-optimizing feature to this process variation.“What-if” exercises with CVI models point toward potential improvements from tailoring of the precursor chemistry and development of special preform architectures.As a link between component design and manufacture, CVI modeling can accelerate successful application of ceramic composites to advanced aerospace and energy components.

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.

Preparation and Performance of C/C-SiC Ceramic Matrix Composites

2018 ◽  
Vol 281 ◽  
pp. 402-407 ◽  
Author(s):  
Fang Hong Yang ◽  
Yan Yan Wang ◽  
Rui Xiang Liu ◽  
Chang Ling Zhou ◽  
Lu Ping Yang ◽  
...  
Keyword(s):  
Bending Strength ◽  
Chemical Vapor ◽  
Ceramic Matrix Composites ◽  
Pyrolytic Carbon ◽  
Carbon Composite ◽  
Chemical Vapor Infiltration ◽  
Growth Time ◽  
Sedimentary Process ◽  
Infiltration Process ◽  
And Performance

Carbon/carbon composite of various density were synthesized via chemical vapor infiltration process, and the sedimentary process of pyrolytic carbon were also researched. The density of the sample increased with the extension of growth time. Density change rate of the samples were various at different stages of the growth process, namely pyrolytic carbon of different densities formed at the different stages. It was found that pyrolytic carbon filled the pores of carbon fiber preform, which can help to relieve the interface stress between the fiber and the ceramic substrate. In order to improve the performance of the composite, SiC and ZrC ceramics were introduced into the carbon/carbon composite via polymer infiltration and pyrolysis (PIP) process. The ability of high temperature resistance and oxidation resistance of the composite were strengthened by the PIP process. The bending strength, tensile strength and compressive strength were also increased with the extension of PIP cycle. The C/C-SiC-ZrC composites were obtain through this process, which are useful in various areas.

A CVI-processing marker study

1995 ◽  
Vol 53 ◽  
pp. 354-355
Author(s):  
G. B. Freeman ◽  
W. J. Lackey ◽  
S. Vaidyaraman
Keyword(s):  
Chemical Vapor ◽  
Ceramic Matrix Composites ◽  
Ceramic Composites ◽  
Processing Technique ◽  
Chemical Vapor Infiltration ◽  
Operating Conditions ◽  
Forced Flow ◽  
Second Phase ◽  
Pull Out ◽  
Structural Applications

Fiber reinforced ceramic composites greatly extend the region of application for ceramic materials because the inclusion of a second phase such as fibers helps to prevent catastrophic failure via the mechanisms of crack branching, deflection, bridging and fiber pull-out. While ceramic composites are excellent candidate materials for high temperature structural applications, many conventional manufacturing processes damage the fibers during fabrication and thereby reduce the strength and toughness from what is theoretically possible. Chemical vapor infiltration (CVI) is an effective and versatile technique for fabrication of ceramic matrix composites which promises to reduce fiber degradation.While CVI is no longer a truly novel processing technique, it is still difficult to predict the best set of operating conditions for what can be a tedious process. Conventional CVI methods may take up to a week to fully infiltrate a small part and even state-of-theart forced flow-thermal gradient CVI (FCVI) processing takes the better part of a day. It is, more over, difficult to monitor the evolution of deposition within a, for example, woven preform.

Preparation and Properties of SiC/Si-B-C-N Ceramic Composites

2016 ◽  
Vol 697 ◽  
pp. 489-493 ◽  
Author(s):  
Ming Wei Chen ◽  
Hai Peng Qiu ◽  
Wei Jie Xie
Keyword(s):  
Fracture Toughness ◽  
Flexural Strength ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Ceramic Composites ◽  
Chemical Vapor Infiltration ◽  
Matrix Composites ◽  
Microscopic Morphology

Abstract：SiC/Si-B-C-N and SiC/SiC ceramic matrix composites were prepared through a combination of chemical vapor infiltration (CVI) and polymer impregnation pyrolysis process(PIP). The microscopic morphology and solid phase structure of the SiC/Si-B-C-N and SiC/SiC composites were investigated by SEM and XRD respectively. Moreover,the flexural strength and fracture toughness were measured using three point bending and single-edge notched beam test. Results showed that the formation of crystalline phases transformation was restrained by introduce BN into matrix phase, which might improve the stability of ceramic matrix composites. Furthermore, the flexural strength and fracture toughness of ceramic matrix composites increased to a maximum of 367 MPa and 26.81 MPa·m1/2 with the 30% PBN weight ratios which might be mainly caused by crack arresting, crack deflecting, micro cracks and fiber pullout.

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