Showing papers on "Ceramic matrix composite published in 2013"
TL;DR: In this paper, the effects of GPLs on the microstructure and mechanical properties of the Al 2 O 3 based ceramic composites were investigated, and the results show that GPLs are well dispersed in the ceramic matrix.
312 citations
10 Oct 2013-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, a graphene nanoplatelet reinforced tantalum carbide composites are synthesized by spark plasma sintering (SPS) at processing conditions of 1850°C and 80-100 MPa.
Abstract: Graphene NanoPlatelets (GNP) reinforced tantalum carbide composites are synthesized by spark plasma sintering (SPS) at processing conditions of 1850 °C and 80–100 MPa. The GNP addition enhances the densification of TaC–GNP composites to 99% theoretical density, while reducing the grain size by over 60% through grain wrapping mechanism. Survival and structure retention of GNP is confirmed through scanning electron microscopy and micro-Raman spectroscopy. Nanoindentation and high load (20–30 N) microindentation are utilized to evaluate elastic modulus and hardness. GNP improves fracture toughness of TaC by up to 99% through toughening mechanisms such as GNP bending, sheet sliding, cracking bridging, and crack deflection.
141 citations
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07 Aug 2013
TL;DR: In this paper, a variety of SiC/SiC composites were fabricated by the 2-dimensional lay-up of 0/90 five-harness satin fabric consisting of Sylramic fiber tows that were then chemical vapor infiltrated (CVI) with BN, CVI with SiC, slurry infiltrated with slurry particles followed by molten infiltration of Si.
Abstract: The matrix cracking of a variety of SiC/SiC composites has been characterized for a wide range of constituent variation. These composites were fabricated by the 2-dimensional lay-up of 0/90 five-harness satin fabric consisting of Sylramic fiber tows that were then chemical vapor infiltrated (CVI) with BN, CVI with SiC, slurry infiltrated with SiC particles followed by molten infiltration of Si. The composites varied in number of plies, the number of tows per length, thickness, and the size of the tows. This resulted in composites with a fiber volume fraction in the loading direction that ranged from 0.12 to 0.20. Matrix cracking was monitored with modal acoustic emission in order to estimate the stress-dependent distribution of matrix cracks. It was found that the general matrix crack properties of this system could be fairly well characterized by assuming that no matrix cracks originated in the load-bearing fiber, interphase, chemical vapor infiltrated Sic tow-minicomposites, i.e., all matrix cracks originate in the 90 degree tow-minicomposites or the large unreinforced Sic-Si matrix regions. Also, it was determined that the larger tow size composites had a much narrower stress range for matrix cracking compared to the standard tow size composites.
120 citations
TL;DR: In this article, alternating pyrolytic carbon/silicon carbide (PyC/SiC) multilayer coatings were applied to the KD-I SiC fibers using chemical vapor deposition (CVD) method.
117 citations
TL;DR: In this paper, three concentric ring regions with different coatings appeared on the surface of the ablated C/C-ZrC-SiC composites: (i) brim ablation region covered by a coating with layered structure including SiO 2 outer layer and ZrO 2 -SiO 2 inner layer; (ii) transition and center ablation regions with molten Zr O 2 coating.
112 citations
01 Jan 2013
TL;DR: The basic science of Advanced Ceramics Raw Materials Forming and Drying Sintering Synthesis of Single Crystals Machining Joining and Coating Fracture Mechanics Testing and Evaluation Insulating Ceramic Materials for Energy Storage, Li-ion Batteries Extruded Cordierite Honeycomb Ceramic Matrix Composites Functionally Graded Materials Intelligent Ceramics.
Abstract: Basic Science of Advanced Ceramics Raw Materials Forming and Drying Sintering Synthesis of Single Crystals Machining Joining and Coating Fracture Mechanics Testing and Evaluation Insulating Ceramics Semiconductive Ceramics Ionic Conductor Piezoelectric Ceramics Dielectric Ceramics Magnetic Ceramics Optoelectroceramics Superconductive Ceramics Engineering Ceramics High Temperature High Strength Ceramics Porous Ceramics for Filtration High Hardness Wear Resistant Ceramics Ceramic Materials for Energy Storage, Li-ion Batteries Extruded Cordierite Honeycomb Ceramics for Environmental Application Ceramics for Biomedical Applications Ceramic Matrix Composites Functionally Graded Materials Intelligent Ceramics.
98 citations
TL;DR: In this paper, the effects of axial thermal residual stresses, cyclic loading and presence of notches on the tensile performance of a SiC-fiber-reinforced barium-magnesium-alumina-silicate (BMAS) ceramic matrix composite were investigated.
Abstract: This study reports on the effects of axial thermal residual stresses, cyclic loading and presence of notches on the tensile performance of a SiC-fiber-reinforced barium–magnesium–alumina–silicate (BMAS) ceramic matrix composite. The residual stress state of the composite was experimentally measured by interrogation of the tensile curves at a uniquely well-defined common intersection point of unloading–reloading cycles in the tensile domain. Notch presence was critical on the material’s mechanical response and promoted catastrophic failure shortly after the achievement of a saturated matrix crack state. The result of cyclic loading was an increase by 20% in sustainable stress throughout loading, as compared to pure tension. Scatter in elastic properties within specimens of different notch-to-width ratios was reconciled with theoretical expectations by application of a translation vector approach in the stress–strain plane, based on the material’s residual stress state. Acoustic emission and infrared thermography provided valuable insight into damage identification, location and sequence.
92 citations
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06 Aug 2013TL;DR: In this paper, the most important oxidation and corrosion studies have recently focused on four major areas: (I) oxidation of precursor-based ceramics, (II) studies of the interphase material in ceramic matrix composites, (III) water vapor interactions with ceramic materials, particularly in combustion environments, and (IV) development of refractory oxide coatings for silicon-based ceramic materials.
Abstract: Ceramics and ceramic matrix composites are candidates for numerous applications in high temperature environments with corrosive gases and deposits. High temperature oxidation and corrosion issues must be considered for these materials. The most important oxidation and corrosion studies have recently focused on four major areas. These are: (I) oxidation of precursor-based ceramics, (II) studies of the interphase material in ceramic matrix composites, (III) water vapor interactions with ceramics, particularly in combustion environments, (IV) development of refractory oxide coatings for silicon-based ceramics. This paper explores the most current work in each of these areas.
82 citations
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04 Oct 2013
TL;DR: A brief history of composites classification can be found in this paper, where the authors discuss the advantages of composite technologies, disadvantages of composite technology, and their application in a variety of applications.
Abstract: Introduction to Composites Definition Brief History of Composites Classification Advantages of Composites Disadvantages of Composites Properties of Composites Applications Questions Bibliography Reference Dispersed Phase Fiber Reinforcements Particulate Materials Nano-reinforcements Questions Bibliography References Further Reading Matrix Materials Polymer Matrix Metallic Matrix Materials Ceramic Matrix Materials Questions Bibliography References Polymer Matrix Composites Processing of Polymer Matrix Composites Advances in Polymer Matrix Composites Structure and Properties of PMCs Environmental Effects on PMCs Applications of PMCs Recycling of PMCs Questions Bibliography References Further Reading Metal Matrix Composites Selection of Reinforcements Processing of Metal Matrix Composites Secondary Processing Machining and Joining of MMCs Properties of Metal Matrix Composites Applications of Metal Matrix Composites Recycling of Metal Matrix Composites Concluding Remarks Questions Bibliography References Ceramic Matrix Composites Failure Behavior of CMCs Toughening Mechanisms in CMCs Processing of Ceramic Matrix Composites Mechanical Properties of CMCs Thermal Conductivity Wear Behavior Applications Concluding Remarks on CMCs Cement-Based Composites Questions Bibliography References Carbon-Carbon Composites Carbon Fiber Reinforcements Matrix Systems Processing of C/C Composites Microstructure of Carbon-Carbon Composites Properties of C/C Composites Oxidation Protection of C/C Composites Applications of C/C Composites Questions Bibliography References Nanocomposites Polymer Nanocomposites Metal Matrix Nanocomposites Ceramic Nanocomposites Questions Bibliography References Further Reading Appendix: Laboratory Practice Index
80 citations
TL;DR: In this paper, the reduction of graphene oxide (GO) during spark plasma sintering (SPS) of the GO/Si 3 N 4 composites was studied by X-ray photoelectron and micro-Raman spectroscopy.
77 citations
TL;DR: In this article, three-dimensional needled Cf/ZrB2-ZrC-SiC composites were successfully fabricated via polymer infiltration and pyrolysis (PIP) using ZrB 2 powder, polycarbosilane, and ZrC precursor as raw materials.
TL;DR: In this article, electrical discharge machining (EDM) was used to process a new class of advanced CMC, that is, those with continuous ceramic fiber reinforcements, and an increase of material removal rate and surface quality without sacrificing tool wear ratio was observed.
Abstract: Ceramic matrix composites (CMC) are considered the next generation of advanced materials used in space and aviation due to their high-temperature strength, creep resistance, chemical resistance, low porosity, and low density. However, these materials are difficult to process owing to the large cutting force and high cost on tool consumption. electrical discharge machining (EDM), featured by the negligible machining force and acceptable tooling cost, is a potential nontraditional machining technique for CMC. In this paper, EDM was used to process a new class of advanced CMC, that is, those with continuous ceramic fiber reinforcements. The challenge is its low material removal rate (MRR) due to the low workpiece conductivity and debris evacuation efficiency. Electrode vibration and dielectric deep flushing were used to promote debris evacuation, and an increase of MRR and surface quality without sacrificing tool wear ratio was observed. Gap voltage, peak current, pulse duration, and duty ratio were studied using design of experiments for deeper understanding of the process. The effect of these parameters was investigated, and an analysis of variance was conducted. The optimal condition was also predicted and experimentally validated. It was found that a high gap voltage or low duty ratio leads to a high machining rate due to improved debris evacuation efficiency. The material removal mechanism was found to be cracking due to thermal expansion of the matrix and breakage of the nonconductive fibers.
TL;DR: In this paper, Spark Plasma Sintering (SPS) is used for the fabrication of highly dense HfB2 monolithic and 26 vol.% SiCw composite, and the desired phase is rapidly formed through a solid-solid combustion synthesis mechanism, while full densification is achieved in 30min at 1350 A when the applied pressure is switched from 20 to 50 MPa after the synthesis reaction.
Abstract: Spark Plasma Sintering is used for the fabrication of highly dense HfB2 monolithic and HfB2–26 vol.% SiCw composite. Reactive SPS from elemental reactants is preferred for the preparation of bulk HfB2 instead of classical sintering. The desired phase is rapidly formed through a solid–solid combustion synthesis mechanism, while full densification is achieved in 30 min at 1350 A when the applied pressure is switched from 20 to 50 MPa after the synthesis reaction. A 99.4% dense whiskers-reinforced HfB2 ceramic matrix composite is also obtained in 30 min by SPS (I = 1350 A, P = 20 MPa) using SHSed HfB2 powders and SiCw. Nevertheless, whiskers degradation into SiCp resulted under such conditions (temperature up to 1830 °C). On the other hand, the presence of whiskers is clearly evidenced in 96% dense products obtained when the applied current was decreased down to 1200 A (1700 °C) while P was increased to 60 MPa.
TL;DR: In this article, the influence of water vapor corrosion on the structural and mechanical properties of a Si/Mullite/BSAS EBC architecture was assessed by furnace thermal cycle testing.
Abstract: The ongoing development of environmental barrier coatings (EBCs) offers the prospect to implement the full potential of silicon-based ceramic matrix composites (CMCs) for high temperature structural applications, more specifically the hot zones of gas turbine engines The current state-of-the-art EBC system comprises a Si bond coat, a mullite (Al6Si2O13) interlayer and a barium–strontium aluminosilicate (BSAS) (Ba1 − xSrxAl2Si2O8; 0 < x < 1) crack-resistant and water vapor attack resistant top coat In this study, fully crystalline air plasma sprayed Si/mullite/BSAS-celsian EBCs were engineered under controlled conditions on SiC substrates The influence of water vapor corrosion on the structural and mechanical properties of a Si/Mullite/BSAS EBC architecture was assessed by furnace thermal cycle testing (ie; 50 and 100 cycles, 2 h/cycles at 1300 °C in water vapor atmosphere) The elastic modulus values of the as-sprayed BSAS top coat (~ 75 ± 6 GPa as determined via indentation) did not exhibit major changes after thermal exposure (~ 78 ± 8 GPa) In addition, the BSAS layer exhibited crack healing at high temperatures, the density of cracks decreasing from 15 cracks/cm in the as-sprayed state to 2 cracks/cm after thermal cycling These characteristics of the BSAS top coat were related to its glass-ceramic nature, the phase/chemical stabilities of the BSAS-celsian at high temperatures and the engineered deposition conditions at which it was deposited The overall performance at high-temperature of this functionally graded EBC architecture is discussed and correlated to its microstructural characteristics
TL;DR: In this paper, the characterization of recycled carbon fibres, in view of their potential application in long-fibre reinforced thermoplastic composite, is presented. The fibres were obtained from epoxy epoxy resins.
Abstract: The aim of this study is the characterization of recycled carbon fibres, in view of their potential application in long-fibre reinforced thermoplastic composite. The fibres were obtained from epoxy...
TL;DR: In this article, a non-oxide ceramic composite with a multilayered matrix was investigated at 1200°C in laboratory air and in steam, and the fatigue performance was evaluated for fatigue stresses ranging from 80 to 200 MPa at a frequency of 1.0
TL;DR: In vitro study ascertained the biocompatibility of the prepared sol-gel-derived HA/MWCNT composite coatings and showed that the addition of low concentrations of MWCNTs had improved effect on the mechanical properties of nanocomposite coatings.
TL;DR: In this paper, a three-dimensional needle carbon fiber reinforced carbon and silicon carbide dual matrix composite (C/C-SiC) was used for brake material, which is a new type of high performance brake material.
TL;DR: In this article, a comparison between RUSM and conventional diamond grinding was made by studying the effects of material removal rate (MRR) on process forces, tool wear and surface roughness.
Abstract: Rotary ultrasonic slot machining (RUSM) of ceramic matrix composites is explored. A comparison is made between RUSM and conventional diamond grinding by studying the effects of material removal rate (MRR) on process forces, tool wear and surface roughness. It was shown that RUSM leads to a significant decrease in process cutting forces and tool wear in comparison to the conventional machining process. Furthermore, the influences of diamond tool characteristics on surface roughness and tool wear are also ascertained.
TL;DR: In this article, a new fibrous ceramics with polycrystalline mullite fibers as the matrix and silica-boron sols as the high temperature binder, which was inspired by the bird's nest structure in nature, were synthesized.
Abstract: New fibrous ceramics with polycrystalline mullite fibers as the matrix and silica–boron sols as the high temperature binder, which was inspired by the bird's nest structure in nature, were synthesized. The most important structure characteristic of this fibrous material is that the silica–boron binder only fixed the fibers at the crossing points rather than filled the pores among the fibers. The elastic behavior was investigated, both at room temperature and elevated temperature. Compared to conventional ceramic matrix composites, the samples show a much higher degree of elasticity because of the bending of the fibers. The rebound resilience decreased slowly with the increase of the temperature, but it still remained 86% of that at ambient temperature at 1000 °C. The sample exhibits good elasticity performance, relatively high strength (2.25 MPa) and high porosity (83%) indicating it is a potential high-temperature seal material.
01 Dec 2013-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the tensile fatigue hysteresis behavior of cross-ply C/SiC composites at room and elevated temperatures in air atmosphere has been investigated, and the hystresis loss energy for strain energy lost per volume during corresponding cycle is formulated in terms of fiber/matrix interface shear stress.
Abstract: The tensile fatigue hysteresis behavior of cross-ply C/SiC composites at room and elevated temperatures in air atmosphere has been investigated in present analysis. The hysteresis modulus and hysteresis loss energy corresponding to different cycles have been analyzed. Based on damage mechanisms of fiber sliding relative to matrix in fiber/matrix interface debonded region upon unloading and subsequent reloading, the hysteresis loops models considering different matrix cracking modes have been developed. The hysteresis loss energy for strain energy lost per volume during corresponding cycle is formulated in terms of fiber/matrix interface shear stress. By comparing experimental hysteresis loss energy with computational values, fiber/matrix interface shear stress of cross-ply C/SiC composites at room and elevated temperatures has been estimated.
TL;DR: In this article, the dispersion of PZT particles in PU matrix, dielectric loss tangent (tan, δ), dynamic storage modulus (E ′), dynamic loss modulus(E ″), and the acoustic absorption coefficient ( α ) of PU/PZT composites were studied by scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), and two-microphone impedance tube, respectively.
TL;DR: In this article, a new energy-based approach is presented which allows for the determination of the interfacial fracture toughness, without assumptions regarding the stress distribution along the interface to be made.
Abstract: Single-fiber push-out tests performed with a Berkovich and a flat-end indenter tip were conducted on the same SiC/PyC/SiC ceramic matrix composite sample for comparison. Push-out measurements were stopped at different stages during the experiment for a detailed microscopic analysis of the front and back side of the sample, to investigate the progression of failure during push-out process. The microscopic analyses reveal differences from the established interpretations which are crucial for quantitative evaluation of interface properties. Based on the microscopic findings, a modified loading schedule comprising unloading–reloading cycles is proposed, which provides access to the dissipative and non-dissipative energy contributions during push-out test. A new energy-based approach is presented which allows for the determination of the interfacial fracture toughness, without assumptions regarding the stress distribution along the interface to be made. Presuming stable crack growth along the complete debonding length, the interfacial fracture toughness of the sample investigated amounts to 44 ± 9 J/m 2 .
TL;DR: In this article, the tensile-tensile fatigue behavior of unidirectional C/SiC ceramic matrix composites at room and elevated temperature was investigated, and an approach to estimate the interface shear stress of ceramic matrices under fatigue loading was developed.
Abstract: The tensile-tensile fatigue behavior of unidirectional C/SiC ceramic matrix composites at room and elevated temperature has been investigated. An approach to estimate the interface shear stress of ceramic matrix composites under fatigue loading has been developed. Based on the damage mechanisms of fiber sliding relative to matrix in the interface debonded region upon unloading and subsequent reloading, the unloading interface reverse slip length and reloading interface new slip length are determined by the fracture mechanics approach. The hysteresis loss energy for the strain energy lost per volume during corresponding cycle is formulatd in terms of interface shear stress. By comparing the experimental hysteresis loss energy with the computational values, the interface shear stress of unidirectional C/SiC ceramic composites corresponding to different cycles at room and elevated temperatures has been predicted.
TL;DR: In this article, an approach to estimate the fiber/matrix interface shear stress of woven ceramic matrix composites during fatigue loading has been developed based on the analysis of the microstructure.
Abstract: An approach to estimate the fiber/matrix interface shear stress of woven ceramic matrix composites during fatigue loading has been developed in this paper. Based on the analysis of the microstructure, the woven ceramic matrix composites were divided into four elements of 0o warp yarns, 90o weft yarns, matrix outside of the yarns and the open porosity. When matrix cracking and fiber/matrix interface debonding occur upon first loading to the peak stress, it is assumed that fiber slipping relative to matrix in the interface debonded region of the 0o warp yarns is the mainly reason for the occurrence of the hysteresis loops of woven ceramic matrix composiets during unloading and subsequent reloading. The unloading interface reverse slip length and reloading interface new slip length are determined by the interface slip mechanisms. The hysteresis loops of three different cases have been derived. The hysteresis loss energy for the strain energy lost per volume during corresponding cycle is formulated in terms of the fiber/matrix interface shear stress. By comparing the experimental hysteresis loss energy with the computational values, the fiber/matrix interface shear stress of woven ceramic matrix composites corresponding to different cycles can then be derived. The theoretical results have been compared with experimental data of two different woven ceramic composites.
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28 Jun 2013TL;DR: In this article, thermal and environmental barrier coatings (TEBCs) are used in gas turbine engines to protect engine hot-section components in the harsh combustion environments, and extend component lifetimes.
Abstract: Ceramic thermal and environmental barrier coatings (TEBCs) are used in gas turbine engines to protect engine hot-section components in the harsh combustion environments, and extend component lifetimes. Advanced TEBCs that have significantly lower thermal conductivity, better thermal stability and higher toughness than current coatings will be beneficial for future low emission and high performance propulsion engine systems. In this paper, ceramic coating design and testing considerations will be described for turbine engine high temperature and high-heat-flux applications. Thermal barrier coatings for metallic turbine airfoils and thermal/environmental barrier coatings for SiC/SiC ceramic matrix composite (CMC) components for future supersonic aircraft propulsion engines will be emphasized. Further coating capability and durability improvements for the engine hot-section component applications can be expected by utilizing advanced modeling and design tools.
TL;DR: In this article, a ZrB2-SiC composite reinforced with the mixture of boron nitride nanotubes (BNNTs) and Boron Nitride nanoplatelets(BNNPs) was prepared by spark plasma sintering.
TL;DR: In this paper, up to 1mm thick Y 2 O 3 coatings were deposited by means of air plasma spraying (APS) on Al O 3 /Al 2 O3 CMC with a reaction-bonded RBAO, which exhibited good adherence in the as-deposited state as well as upon isothermal annealing up to 1400°C.
Abstract: Al 2 O 3 /Al 2 O 3 ceramic matrix composites (CMC) are candidate materials for hot-gas leading components of gas turbines. Since Al 2 O 3 /Al 2 O 3 CMC are prone to hot-corrosion in combustion environments, the development of environmental barrier coatings (EBC) is mandatory. Owing to its favorable chemical stability and thermal properties, Y 2 O 3 is considered a candidate EBC material for Al 2 O 3 /Al 2 O 3 CMC. Up to 1 mm thick Y 2 O 3 coatings were deposited by means of air plasma spraying (APS) on Al 2 O 3 /Al 2 O 3 CMC with a reaction-bonded Al 2 O 3 bond-coat (RBAO). APS Y 2 O 3 coatings exhibit a good adherence in the as-deposited state as well as upon isothermal annealing up to 1400 °C. Moreover, furnace cyclic testing performed at 1200 °C revealed an excellent durability. This is explained by the formation of a continuous, approximately 1 μm thick reaction zone at the APS Y 2 O 3 /RBAO interface. The reaction zone between Y 2 O 3 and Al 2 O 3 comprises three layers of thermodynamically stable yttrium-aluminates exhibiting strong bonding, respectively.
TL;DR: In this article, the loading/unloading tensile behavior of cross-ply C/SiC ceramic matrix composites at room temperature has been investigated, and the fracture mechanics approach has been used to model the hysteresis loops of crossply ceranic matrix composite including the effect of matrix cracking.
Abstract: In this paper, the loading/unloading tensile behavior of cross-ply C/SiC ceramic matrix composites at room temperature has been investigated. The loading/unloading stress–strain curve exhibits obvious hysteresis behavior. An approach to model the hysteresis loops of cross-ply ceranic matrix composites including the effect of matrix cracking has been developed. Based on the damage mechanisms of fiber sliding relative to matrix during unloading and subsequent reloading, the unloading interface reverse slip length and reloading interface new slip length of different matrix cracking modes are obtained by the fracture mechanics approach. The hysteresis loops of cross-ply C/SiC ceramic matrix composites corresponding to different peak stresses have been predicted.
TL;DR: The flexural strength and fracture toughness of C/ZrC composites with 0.05μm thickness SiC layer were 252 MPa and 13.6 MPa, respectively as mentioned in this paper.