Contribution of Thermal Radiation to the Temperature Profile of Ceramic Composite Materials

1994 ◽  
Vol 116 (3) ◽  
pp. 583-586 ◽  
Author(s):  
A. Tremante ◽  
F. Malpica
Keyword(s):  
Control Systems ◽  
Ceramic Composite ◽  
Nuclear Reactors ◽  
Numerical Procedure ◽  
Ceramic Matrix Composites ◽  
Heat Fluxes ◽  
Matrix Composites ◽  
Flux Model ◽  
Planar Medium ◽  
Potential Use

The steady energy transfer equation for simultaneous conduction and radiation in an absorbing, emitting, and nonscattering gray planar medium is studied theoretically. For extremely high-temperature applications, where radiative transfer plays an important role, ceramic-matrix composites, considered as semitransparent materials, are being explored for potential use in turbine and compressor components, spacecraft structures, engine control systems, and nuclear reactors. Exact solution of the above-mentioned radiative problems is seldom possible and time-consuming numerical approximations are then used. A technique combining an accurate physical formulation, the two-flux model, coupled to a fast numerical procedure for the calculation of the temperature and heat fluxes is described.

Contribution of Thermal Radiation to the Temperature Profile of Ceramic Composite Materials

1993 ◽  
Author(s):  
Andrés Tremante ◽  
Freddy Malpica
Keyword(s):  
Control Systems ◽  
Ceramic Composite ◽  
Large Time ◽  
Numerical Procedure ◽  
Ceramic Matrix Composites ◽  
Heat Fluxes ◽  
Matrix Composites ◽  
Flux Model ◽  
Planar Medium ◽  
Potential Use

The steady energy transfer equation by simultaneous conduction and radiation in an absorbing, emitting and non-scattering gray planar medium is studied theoretically. For extremely high-temperature applications, where radiative transfer plays an important role, ceramic-matrix composites, considered as semitransparent materials, are being explored for potential use in turbine and compressors components, spacecraft structures, engine control systems and nuclear reactors. Exact solution of the above mentioned radiative problems is seldom possible and large-time consuming numerical approximations are then used. A technique combining an accurate physical formulation, the two-flux model, coupled to a fast numerical procedure for the calculation of the temperature and heat fluxes is described.

Analysis of the Temperature Profile of Ceramic Composite Materials Exposed to Combined Conduction–Radiation Between Concentric Cylinders

1998 ◽  
Vol 120 (2) ◽  
pp. 271-275 ◽  
Author(s):  
A. Tremante ◽  
F. Malpica
Keyword(s):  
Ceramic Composite ◽  
Numerical Study ◽  
Thermal Characteristics ◽  
Ceramic Matrix Composites ◽  
Gray Model ◽  
Matrix Composites ◽  
Semitransparent Materials ◽  
Concentric Cylinders ◽  
Benchmark Solutions ◽  
Potential Use

A numerical study is made of the thermal characteristics of semitransparent materials exposed to simultaneous conduction and radiation between concentric cylinders. For extremely high-temperature applications, where radiative transfer plays an important role, ceramic-matrix composites, considered as semitransparent materials, are being explored for potential use in turbine and compressor components, spacecraft structures, engine control systems and nuclear reactors. Through the use of a gray model and the two-flux method, specialized equations are developed that generate a system of nonlinear ordinary differential equations. To facilitate the solution of this system, an iterative strategy is adopted. In order to demonstrate the versatility and accuracy of the proposed methodology, the results of several numerical experiments are presented and compared with benchmark solutions.

scholarly journals Analysis of the Temperature Profile of Ceramic Composite Materials Exposed to Combined Conduction-Radiation Between Concentric Cylinders

1997 ◽  
Author(s):  
Andrés Tremante ◽  
Freddy Malpica
Keyword(s):  
Ceramic Composite ◽  
Numerical Study ◽  
Thermal Characteristics ◽  
Ceramic Matrix Composites ◽  
Gray Model ◽  
Matrix Composites ◽  
Semitransparent Materials ◽  
Concentric Cylinders ◽  
Benchmark Solutions ◽  
Potential Use

A numerical study is made of the thermal characteristics of semitransparent materials exposed to simultaneous conduction and radiation between concentric cylinders. For extremely high-temperature applications, where radiative transfer plays an important role, ceramic-matrix composites, considered as semitransparent materials, are being explored for potential use in turbines and compressors components, spacecraft structures, engine control systems and nuclear reactors. Through the use of a gray model and the the two flux method, specialized equations are developed that generate a system of nonlinear ordinary differential equations. To facilitate the solution of this system, an iterative strategy is adopted. In order to demonstrate the versatility and accuracy of the proposed methodology, the results of several numerical experiments are presented and compared with benchmark solutions.

Processing of Polymeric Precursor, Ceramic Matrix Composites

1988 ◽  
Vol 120 ◽  
Author(s):  
R. J. Diefendorf ◽  
R. P. Boisvert
Keyword(s):  
Barrier Layer ◽  
Ceramic Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Processing Technique ◽  
Matrix Composites ◽  
Brittle Behavior ◽  
Sic Ceramic ◽  
Sic Whiskers ◽  
Polymer Pyrolysis

AbstractCeramic matrix composites have been produced by utilizing polymer pyrolysis as the processing technique. The precursor, polyvinylsilane, is a viscous, thermosetting polymer which yields a predominantly SiC ceramic material when pyrolyzed. This organometallic polymer in combination with SiC fibers and SiC whiskers was used to fabricate ceramic matrix composites. One of the major problems with a brittle/brittle composite system in which strong coupling exist between the fibers and matrix is the characteristic catastrophic failure that occurs once the strain to failure of one of the constituents is exceeded. This brittle behavior can be altered by the application of a suitable barrier layer between the fiber and matrix. Due to the success of a barrier layer between fiber and matrix in producing higher performance composites, multiple barrier layers were used to further improve the performance of the ceramic composite.

scholarly journals ASME Code Rules and ASTM Standards Integration for Ceramic Composite Core Materials and Components1

2021 ◽  
Vol 2048 (1) ◽  
pp. 012020
Author(s):  
J W Geringer ◽  
Y Katoh ◽  
S Gonczy ◽  
T Burchell ◽  
M Mitchell ◽  
...  
Keyword(s):  
Composite Materials ◽  
Ceramic Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Composites ◽  
Test Methods ◽  
Code Design ◽  
Matrix Composites ◽  
Asme Code ◽  
Ceramic Composite Materials ◽  
American Society

Abstract Fiber-reinforced ceramic matrix composites have many desirable properties for high-temperature nuclear applications, including excellent thermal and mechanical properties and reasonable to outstanding radiation resistance. Over the last 20 years, the use of ceramic composite materials has already expanded in many commercial nonnuclear industries as fabrication and application technologies mature. The new ASME design and construction rules under Section III, Subsection HH, Subpart B lay out the requirements and criteria for materials, design, machining and installation, inspection, examination, testing, and the marking procedure for ceramic composite core components, which is similar to the established graphite code under Section III, Subsection HH, Subpart A. Moreover, the general requirements listed in Section III, Subsection HA, Subpart B are also expanded to include ceramic composite materials. The code rules rely heavily on the development and publication of standards for composite specification, classification, and testing of mechanical, thermal, and other properties. These test methods are developed in the American Society for Testing and Materials Committee C28 on Advanced Ceramics with a current focus on ceramic composite tubes. Details of the composites code, design methodology, and similarities to the graphite code, as well as guidance for the development of specifications for ceramic composites for nuclear application and recent standard developments, are discussed. The next step is to “close the gap” to support licensing aspects by validating the code with benchmarking data.

The Influence of Heat Treatment upon Fiber Pull-Out in a Ceramic Composite

1988 ◽  
Vol 120 ◽  
Author(s):  
M. D. Thouless ◽  
O. Sbaizero ◽  
E. Bischoff ◽  
E. Y. Luh
Keyword(s):  
Ceramic Composite ◽  
Ceramic Matrix Composites ◽  
Matrix Composites ◽  
Matrix Interface ◽  
Shear Lag ◽  
Weibull Statistics ◽  
Pull Out ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

AbstractThe toughness of ceramic-matrix composites is strongly influenced by fiber pull-out. The extent of the pull-out depends upon the properties of the fiber and the fiber/matrix interface. Samples of a SiC/LAS composite were subjected to different heat treatments in order to systematically vary these properties. The predicted distribution of the fiber pull-out lengths was calculated by combining a shear lag analysis with Weibull statistics for the fiber strengths. Comparison of the analysis with experiments and microstructural observations contribute to an understanding of the role of the fiber/matrix interface upon the mechanical properties.

Effect of a LZSA Glass Infiltration on the Properties of a Porous Ceramic Composite Material Derived from Polysiloxane/Al/Nb

2008 ◽  
Vol 591-593 ◽  
pp. 409-414
Author(s):  
Wilson Acchar ◽  
Marcus Diniz ◽  
Ygor Alexandre A. Fonseca ◽  
F.C.C. Costa
Keyword(s):  
Composite Material ◽  
Ceramic Composite ◽  
Porous Ceramic ◽  
Physical And Mechanical Properties ◽  
Ceramic Matrix Composites ◽  
Cost Effective ◽  
Matrix Composites ◽  
Aluminum Powders ◽  
Ceramic Composite Material ◽  
Polymer Pyrolysis

By using the active filler controlled polymer pyrolysis, new and cost-effective composite materials can be obtained. In this work, ceramic matrix composites were prepared by using this precursor route, using a polysiloxane network filled with metallic niobium and aluminum powders as active fillers. The mixtures were blended, uniaxially warm pressed, and pyrolyzed in flowing argon at 1400 °C. Porous ceramic preforms were infiltrated with a LZSA glass material, in order to improve the density of a porous composite material. The properties of the pyrolyzed composite material and the effect of the LZSA infiltration on the Al2O3-NbC-SiOC ceramic composite material were investigated. The results have showed that the infiltration processes has improved the physical and mechanical properties of the composite material.

A Study of Bridged Delaminations in High Temperature Laminates Under Heat Flux Loading

Materials ◽  
2003 ◽  
Author(s):  
Thomas Siegmund ◽  
Ashwin Hattiangadi
Keyword(s):  
Heat Flux ◽  
High Temperature ◽  
Thermal Loading ◽  
Significant Contribution ◽  
Thermal Protection ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
High Heat ◽  
Heat Fluxes ◽  
Matrix Composites

High temperature ceramic matrix composites (CMCs) are material considered in many applications where high heat fluxes constitute a significant contribution to loading. The laminates can fulfill their function as thermal protection layers only if they stay intact, i.e. without internal delaminations or spalling, such that the heat flux remains undisturbed by such events. Crack bridging is an important effect in CMCs, and its implication to CMC laminates under thermal loading is investigated.

scholarly journals Investigation of Failure Mechanisms in Ceramic Composites as Potential Railway Brake Disc Materials

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5141
Author(s):  
Jeongguk Kim
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Ceramic Composite ◽  
Failure Mechanisms ◽  
Ceramic Matrix Composites ◽  
Tensile Tests ◽  
Ceramic Composites ◽  
Matrix Composites ◽  
Fracture Characteristics ◽  
Ceramic Composite Materials

Ceramic composite materials have been efficiently used for high-temperature structural applications with improved toughness by complementing the shortcomings of monolithic ceramics. In this study, the fracture characteristics and fracture mechanisms of ceramic composite materials were studied. The ceramic composite material used in this study is Nicalon ceramic fiber reinforced ceramic matrix composites. The tensile failure behavior of two types of ceramic composites with different microstructures, namely, plain-weave and cross-ply composites, was studied. Tensile tests were performed on two types of ceramic composite material specimens. Microstructure analysis using SEM was performed to find out the relationship between tensile fracture characteristics and microstructure. It was found that there was a difference in the fracture mechanism according to the characteristics of each microstructure. In this study, the results of tensile tests, failure modes, failure characteristics, and failure mechanisms were analyzed in detail for two fabric structures, namely, plain-weave and cross-ply structures, which are representative of ceramic matrix composites. In order to help understanding of the fracture process and mechanism, the fracture initiation, crack propagation, and fracture mechanism of each composite material are schematically expressed in a two-dimensional figure. Through these results, it is intended to provide useful information for the design of ceramic composite materials based on the mechanistic understanding of the fracture process of ceramic composite materials.

Design and Implementation of Actively Cooled Panels for Scramjets

2007 ◽  
Author(s):  
Natasha Vermaak ◽  
Lorenzo Valdevit ◽  
Frank W. Zok ◽  
Anthony G. Evans
Keyword(s):  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Design Tool ◽  
Heat Fluxes ◽  
Operating Conditions ◽  
Advanced Materials ◽  
Matrix Composites ◽  
High Temperature Alloys ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Analyses

The operating conditions of scramjet engines demand designs that include active cooling by the fuel and the use of lightweight materials that withstand extreme heat fluxes and structural loads. An optimization tool has previously been introduced to direct the development of advanced materials that outperform existing high temperature alloys and compete with ceramic matrix composites. This analysis presents verification and accretion of the analytical design tool through a combination of numerical and experimental techniques. Selected computational fluid dynamics (CFD) analyses have been performed to verify critical thermal assumptions. A high-power CO2 laser provides heat fluxes representative of hypersonic flight conditions.

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