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1
Sun, Chen Cheng, Zi Jun Hu, Tong Qi Li, Hong Bo Zhang, Zhi Jie Sun, and Zuo Guang Zhang. "Preparation and Properties of Ceramic Tiles for Heat Insulation." Materials Science Forum 546-549 (May 2007): 2157–62. http://dx.doi.org/10.4028/www.scientific.net/msf.546-549.2157.
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The bulk tiles of ceramic fibers reinforced aerogel were prepared from two reinforcements, evenly dispersed ceramic fibers and sintered tiles. It has been found that ceramic fiber-reinforced aerogels showed higher thermal conductivity than aerogel itself. Shrinkage of aerogels in chopped fiber reinforced aerogel composites showed similar tendency as pure aerogel during gelation, but the shrinkage was prohibited during supercritical drying. By contrary, in the case of sintered tile reinforced aerogel, shrinkage of aerogel was completely limited in both gelation and drying processes. Average of about 50% increase of compressive strengths of the sintered tile reinforced aerogel to sintered tiles were obtained with an average density increase of about 36%, their thermal conductivity depressed slightly.
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Babashov, V. G., N. M. Varrik, V. G. Maksimov, and O. N. Samorodova. "OXIDE FIBER COATED WITH SILICON CARBIDE FOR PRODUCING COMPOSITE MATERIALS." Aviation Materials and Technologies, no. 3 (2021): 94–104. http://dx.doi.org/10.18577/2713-0193-2021-0-3-94-104.
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The article presents the results of an experiment on the application of a silicon carbide coating on an alumina fiber and studies the properties of the resulting coated fibers. The purpose of applying a barrier coating to the fibers is to protect the fiber from degradation during the manufacturing of a ceramic composite material. The paper gives the characteristics of barrier coatings, such as thickness, continuity, structure, thermal and thermo-oxidative properties. The obtained data will be useful in the development of new types of ceramic composite materials reinforced with fibers.
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Holčapek, Ondřej, Jaroslava Kot'átková, and Pavel Reiterman. "Development of Composite for Thermal Barriers Reinforced by Ceramic Fibers." Advances in Civil Engineering 2018 (2018): 1–10. http://dx.doi.org/10.1155/2018/3251523.
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The paper introduces the development process of fiber-reinforced composite with increased resistance to elevated temperatures, which could be additionally increased by the hydrothermal curing. However, production of these composites is extremely energy intensive, and that is why the process of the design reflects environmental aspects by incorporation of waste material—fine ceramic powder applied as cement replacement. Studied composite materials consisted of the basalt aggregate, ceramic fibers applied up to 8% by volume, calcium-aluminous cement (CAC), ceramic powder up to 25% by mass (by 5%) as cement replacement, plasticizer, and water. All studied mixtures were subjected to thermal loading on three thermal levels: 105°C, 600°C, and 1000°C. Experimental assessment was performed in terms of both initial and residual material properties; flow test of fresh mixtures, bulk density, compressive strength, flexural strength, fracture energy, and dynamic modulus of elasticity were investigated to find out an optimal dosage of ceramic fibers. Resulting set of composites containing 4% of ceramic fibers with various modifications by ceramic powder was cured under specific hydrothermal condition and again subjected to elevated temperatures. One of the most valuable benefits of additional hydrothermal curing of the composites lies in the higher residual mechanical properties, what allows successful utilization of cured composite as a thermal barrier in civil engineering. Mixtures containing ceramic powder as cement substitute exhibited after hydrothermal curing increase of residual flexural strength about 35%; on the other hand, pure mixture exhibited increase up to 10% even higher absolute values.
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Shestakov, A. M. "Silicon carbide fibers and whiskers for ceramic matrix composites (review)." Industrial laboratory. Diagnostics of materials 87, no. 8 (August 21, 2021): 51–63. http://dx.doi.org/10.26896/1028-6861-2021-87-8-51-63.
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An increase the operating temperature range of structural elements and aircraft assemblies is one of the main goals in developing advanced and new models of aerospace equipment to improve their technical characteristics. The most heat-loaded aircraft structures, such as a combustion chamber, high-pressure turbine segments, nozzle flaps with a controlled thrust vector, must have a long service life under conditions of high temperatures, an oxidizing environment, fuel combustion products, and variable mechanical and thermal loads. At the same time, modern Ti and Ni-based superalloys have reached the limits of their operating temperatures. The leading world aircraft manufacturers — General Electric (USA), Rolls-Royce High Temperature Composite Inc. (USA), Snecma Propulsion Solide (France) — actively conduct fundamental research in developing ceramic materials with high (1300 – 1600°C) and ultrahigh (2000 – 2500°C) operating temperatures. However, ceramic materials have a number of shortcomings attributed to the high brittleness and low crack resistance of monolithic ceramics. Moreover, manufacturing of complex configuration and large-sized ceramic parts faces serious difficulties. Nowadays, ceramic composite materials with a high-temperature matrix (e.g., based on ZrC-SiC) and reinforcing filler, an inorganic fiber, (e.g., silicon carbide) appeared most promising for operating temperatures above 1200°C and exhibited enhanced energy efficiency. Ceramic fibers based on silicon compounds possess excellent mechanical properties: the tensile strength more than 2 GPa, modulus of elasticity more than 200 GPa, and thermal resistance at a temperature above 800°C, thus making them an essential reinforcing component in metal and ceramic composites. This review is devoted to silicon carbide core fibers obtained by chemical vapor deposition of silicon carbide onto a tungsten or carbon core, which makes it possible to obtain fibers a 100 – 150 μm in diameter to be used in composites with a metal matrix. The coreless SiC-fibers with a diameter of 10 – 20 μm obtained by molding a polymer precursor from a melt and used mainly in ceramic composites are also considered. A comparative analysis of the phase composition, physical and mechanical properties and thermal-oxidative resistance of fibers obtained by different methods is presented. Whiskers (filamentary crystals) are also considered as reinforcing fillers for composite materials along with their properties and methods of production. The prospects of using different fibers and whiskers as reinforcing fillers for composites are discussed.
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Jacob, Reenu, and Jayakumari Isac. "Morphological, thermal and optical studies of jute-reinforced PbSrCaCuO–polypropylene composite." Modern Physics Letters B 30, no. 31 (November 20, 2016): 1650379. http://dx.doi.org/10.1142/s0217984916503796.
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New research with modern technologies has always grabbed substantial attention. Conservation of raw materials like natural fibers has helped composite world to explore eco-friendly components. The aim of this paper is to study the potential of jute fiber-reinforced ceramic polymers. Alkali-treated jute fiber has been incorporated in a polypropylene ceramic matrix at different volume fractions. The morphological, thermal and optical studies of jute-reinforced ceramic Pb2Sr2CaCu2O9 (PbSrCaCuO) are studied. Morphological results evidently demonstrate that when the polypropylene ceramic matrix is reinforced with jute fiber, interfacial interaction between the varying proportions of the jute fiber and ceramic composite takes place. TGA and DSC results confirm the enhancement in the thermal stability of ceramic composites reinforced with jute fiber. The UV analysis of the composite gives a good quality measure on the optical properties of the new composite prepared.
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Freeman, G. B., W. J. Lackey, and T. L. Starr. "Characterization of BN-coated ceramic fibers." Proceedings, annual meeting, Electron Microscopy Society of America 46 (1988): 740–41. http://dx.doi.org/10.1017/s042482010010576x.
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It is well known that ceramic materials possess excellent thermal properties for use at high temperatures but are subject to brittle failure. The incorporation of a suitable second phase (powder or fiber) can mitigate that brittle character and result in a composite material which actually possesses mechanical properties superior to those of competitive traditional materials. It has been shown that the remaining tendency toward brittle failure can be further reduced if the incorporated fiber exhibits a weak rather than strong bond with the matrix. This encourages debonding, crack deflection and fiber pull-out which all contribute to fracture toughness. It was the goal of this project to coat commercial Nextel type 312 fibers (composition: 3 moles Al2O3, 2 moles SiO2, and 1 mole B2O3) with an approximately 0.1 μm thin film of boron nitride (BN) for inclusion in a slip-cast sintered silica matrix.
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Ni, Xin Hua, Bao Feng Li, Guo Hui Zhong, and Lei Zhao. "Size Dependent Thermal Expansion Coefficient of Rod-Shaped Oxide Eutectic Ceramic." Advanced Materials Research 105-106 (April 2010): 146–49. http://dx.doi.org/10.4028/www.scientific.net/amr.105-106.146.
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Rod-shaped oxide eutectic ceramics fabricated through SHS process can acquire outstanding mechanical properties. First, Four-phase model method was used to study effective disturbance strain of rod-shaped oxide eutectic ceramics produced by nano fibers with inter-phases, then average strain of rod-shaped oxide eutectic ceramics aroused thermal inconsistency is obtained. The effective thermal expansion longitudinal strain and transverse strain of rod-shaped oxide eutectic ceramics are determined by the average strain. Rod-shaped oxide eutectic ceramics is transverse isotropy and has two independent thermal expansion coefficients. The results show that the thermal expansion coefficients of rod shaped oxide eutectic ceramics are dependent on the diameter of nano-fiber. The thermal expansion coefficients will decrease when the diameter of nano-fiber decrease.
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Licciulli, Antonio, Antonio Chiechi, Daniela Diso, and Alfonso Maffezzoli. "Ceramic Composites for Automotive Friction Devices." Advances in Science and Technology 45 (October 2006): 1394–98. http://dx.doi.org/10.4028/www.scientific.net/ast.45.1394.
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Advanced braking devices can represent a promising application for ceramic matrix composites (CMC) with functional and structural properties. If the actual advanced braking materials could be at least partially replaced by CMCs, it might become the first consumer market for these materials. CMC containing three main phases, silicon carbide, graphite and carbon fibers were prepared. A systematic analysis of the processing-structure-properties relationship of the composite is carried out. In particular, silicon carbide provides the necessary hardness, whereas graphite is used for its lubricating properties, and carbon fibers are used as reinforcement. The samples, prepared using a reactive bonding technique, exhibited adequate mechanical properties, high resistance to thermal shocks and good stability after many thermal cycles. Morphological and structural investigations have been performed to optimize the content of each component. Preliminary tribological investigations are presented.
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Silvestre, J., N. Silvestre, and J. de Brito. "An Overview on the Improvement of Mechanical Properties of Ceramics Nanocomposites." Journal of Nanomaterials 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/106494.
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Due to their prominent properties (mechanical, stiffness, strength, thermal stability), ceramic composite materials (CMC) have been widely applied in automotive, industrial and aerospace engineering, as well as in biomedical and electronic devices. Because monolithic ceramics exhibit brittle behaviour and low electrical conductivity, CMCs have been greatly improved in the last decade. CMCs are produced from ceramic fibres embedded in a ceramic matrix, for which several ceramic materials (oxide or non-oxide) are used for the fibres and the matrix. Due to the large diversity of available fibres, the properties of CMCs can be adapted to achieve structural targets. They are especially valuable for structural components with demanding mechanical and thermal requirements. However, with the advent of nanoparticles in this century, the research interests in CMCs are now changing from classical reinforcement (e.g., microscale fibres) to new types of reinforcement at nanoscale. This review paper presents the current state of knowledge on processing and mechanical properties of a new generation of CMCs: Ceramics Nanocomposites (CNCs).
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Liu, G., R. Ghosh, D. Mousanezhad, A. Vaziri, and H. Nayeb-Hashemi. "Thermal conductivity of biomimetic leaf composite." Journal of Composite Materials 52, no. 13 (September 21, 2017): 1737–46. http://dx.doi.org/10.1177/0021998317733316.
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The venous morphology of a typical plant leaf affects its mechanical and thermal properties. Such a material could be considered as a fiber reinforced composite structure where the veins and the rest of the leaf are considered as two materials having highly contrast mechanical and thermal properties. The variegated venations found in nature is idealized into three principal fibers—the central mid-fiber corresponding to the mid-rib, straight parallel secondary fibers attached to the mid-fiber representing the secondary veins, and then another set of parallel fibers emanating from the secondary fibers mimicking the tertiary veins of a typical leaf. This paper addresses the in-plane thermal conductivity of such a composite by considering such a venous fiber morphology embedded in a matrix material. We have considered two cases, fibers having either higher or lower conductivity respect to the matrix. The tertiary fibers do not interconnect the secondary fibers in our present study. We carry out finite element based computational investigation of the thermal conductivity of these composites under uniaxial thermal gradients and study the effect of different fiber architectures. To this end, we use two broad types of architectures both having similar central main fiber but differing in either having only secondary fibers or additional tertiary fibers. The fiber and matrix volume fractions are kept constant and a comparative parametric study is carried out by varying the inclination of the secondary fibers. We find the heat conductivity in the direction of the main fiber (Y direction) increases significantly as the fiber angle of the secondary increases. Furthermore, for composite with metal fibers, the conductivity in the Y direction is further enhanced when composite is manufactured by having secondary fibers forming a closed cell structure. However, for composite with ceramic fibers, the conductivity of the composite in the Y direction is little affected by having secondary fibers closed. An opposite behavior is observed when considering conductivity of the composite in the X direction. The conductivity of the composite in the X direction is reduced with increase in the angle of the secondary fibers. Higher conductivity in the X direction is achieved for composite with no closed cells for composites with metal fibers. The results also indicate that for composites with the constant fiber volume fraction, morphology of tertiary fibers may not significantly alter material conductivities. In conclusion, introducing a leaf-mimicking topology in fiber architecture can provide significant additional degrees of tunability in design of these composite structures.
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Zhao, Ying Na, Wen Li Zhang, Gui Qin Hou, and Li Hong Liu. "The Joining of Oxide Ceramics with Quartz Fiber by Interlayer." Advanced Materials Research 337 (September 2011): 392–95. http://dx.doi.org/10.4028/www.scientific.net/amr.337.392.
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The joining of ZrO2 ceramic and quartz fiber was realized by glass interlayer heat-treatment at 800 °C for 1h. Using the low-temperature liquid reaction of B2O3-SiO2 and B2O3-ZrO2 and the properties change of borosilicate glass, the two kind materials of different thermal expansion coefficients achieved joint by B2O3 as the interlayer material. Through observing the micro-morphology of joint samples at different heat-treatment temperature, and combining with the fibers’ high temperature properties, the optimum joining temperature was investigated. According to the phase diagrams of B2O3-SiO2 and B2O3-ZrO2 and SEM results of joints region, the joint mechanism of density ceramics and fiber weaves was discussed in detail.
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More, K. L., E. Lara-Curzio, and R. A. Lowden. "Surface roughness characterization of various ceramic fibers using AFM and low-voltage SEM." Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994): 1066–67. http://dx.doi.org/10.1017/s0424820100173066.
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The effect of interfacial properties in fiber-reinforced ceramic matrix composites is critical to the overall mechanical behavior of the composite material. The creation of a relatively weak fiber/matrix interface allows for the beneficial actions of debonding and fiber pull-out to occur, thus improving the fracture toughness and, in many cases, the ultimate strength of the composite. To date, the best room temperature interfacial properties have been achieved by coating the fibers with either carbon or boron nitride. There are several factors which contribute to the interfacial properties of a composite, including the residual stress (clamping stress) present at the fiber/matrix interface, which is a result of differences in thermal expansion, and the fiber surface roughness. In this study, the surfaces of several ceramic fibers have been characterized qualitatively using a Hitachi S-4500 FEG SEM operated at low voltages and quantitatively using a Topometrix atomic force microscope (AFM). This study is part of an overall program relating fiber surface roughness to the interfacial shear stress.
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Beckman, Ivan, Christine Lozano, Elton Freeman, and Guillermo Riveros. "Fiber Selection for Reinforced Additive Manufacturing." Polymers 13, no. 14 (July 7, 2021): 2231. http://dx.doi.org/10.3390/polym13142231.
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The purpose of this review is to survey, categorize, and compare the mechanical and thermal characteristics of fibers in order to assist designers with the selection of fibers for inclusion as reinforcing materials in the additive manufacturing process. The vast “family of fibers” is described with a Venn diagram to highlight natural, synthetic, organic, ceramic, and mineral categories. This review explores the history and practical uses of particular fiber types and explains fiber production methods in general terms. The focus is on short-cut fibers including staple fibers, chopped strands, and whiskers added to polymeric matrix resins to influence the bulk properties of the resulting printed materials. This review discusses common measurements for specific strength and tenacity in the textile and construction industries, including denier and tex, and discusses the proposed “yuri” measurement unit. Individual fibers are selected from subcategories and compared in terms of their mechanical and thermal properties, i.e., density, tensile strength, tensile stiffness, flexural rigidity, moisture regain, decomposition temperature, thermal expansion, and thermal conductivity. This review concludes with an example of the successful 3D printing of a large boat at the University of Maine and describes considerations for the selection of specific individual fibers used in the additive manufacturing process.
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Reiterman, Pavel, Ondřej Holčapek, Marcel Jogl, and Petr Konvalinka. "Physical and Mechanical Properties of Composites Made with Aluminous Cement and Basalt Fibers Developed for High Temperature Application." Advances in Materials Science and Engineering 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/703029.
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Present paper deals with the experimental study of the composition of refractory fiber-reinforced aluminous cement based composites and its response to gradual thermal loading. Basalt fibers were applied in doses of 0.25, 0.5, 1.0, 2.0, and 4.0% in volume. Simultaneously, binder system based on the aluminous cement was modified by fine ground ceramic powder originated from the accurate ceramic blocks production. Ceramic powder was dosed as partial replacement of used cement of 5, 10, 15, 20, and 25%. Influence of composition changes was evaluated by the results of physical and mechanical testing; compressive strength, flexural strength, bulk density, and fracture energy were determined on the different levels of temperature loading. Increased dose of basalt fibers allows reaching expected higher values of fracture energy, but with respect to results of compressive and flexural strength determination as an optimal rate of basalt fibers dose was considered 0.25% in volume. Fine ground ceramic powder application led to extensive increase of residual mechanical parameters just up to replacement of 10%. Higher replacement of aluminous cement reduced final values of bulk density but kept mechanical properties on the level of mixtures without aluminous cement replacement.
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Jogl, Marcel. "Performance of Dosage of Ceramic Chopped Fibers in Aluminous Cement-Based Composites after Exposure to High Temperatures." Key Engineering Materials 722 (December 2016): 38–43. http://dx.doi.org/10.4028/www.scientific.net/kem.722.38.
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The results of an experimental investigation of the influence of chopped alumina-silica bulk fibers on residual mechanical properties of lightweight cement-based composites for high temperature application are obtained. The matrix of studied specimens is based on aluminous cement, because of its sufficient temperature resistance over 1000 °C. Thermal ceramic bulk fiber offer a maximum temperature range of between 1200° to 1500 °C. They also provide excellent chemical stability and resistance to chemical attack. If wet by oil or water, thermal and physical properties will be fully restored after drying. The benefits of using ceramic bulk fibers were evaluated by the results of physical and mechanical testing; compressive strength, flexural strength and bulk density were determined on the different levels of temperature loading. The prismatic specimens, having dimensions of 40×40×160 mm3, are cured 28 days in humid environment and after that time dried and subjected to temperatures of 600 °C and 1000 °C for 3 hours. The experimental composites differed in doses of fibers, which are 0.0 %, 0.5 % and 2.0 % by volume.
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He, Lin Kai, You Hong Sun, Mei Jun Liu, and Qing Nan Meng. "Effect of the Addition of Short Carbon Fiber on Thermal Insulation Properties of ZrB2- SiC Hot-Pressed Ceramics." Materials Science Forum 993 (May 2020): 785–90. http://dx.doi.org/10.4028/www.scientific.net/msf.993.785.
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Short carbon fibers reinforced ZrB2-SiC ceramics were prepared by hot pressing sintering process. The short carbon fibers with different volume fractions (0.2.4.6.8.10.20) were added for improving the thermal insulation properties of ZrB2-SiC ceramics. The experimental results showed that as the content of short carbon fiber increased, the thermal diffusivity decreased from 43.9m2/s to 32.9m2/s, the thermal conductivity decreased from 104.3 W/(m·K) to 72.9 W/(m·K) and thermal insulation performance reduced by 43.1%, respectively. The enhancement of the thermal insulation properties is mainly due to high interfacial thermal resistance of short carbon fiber and matrix.
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Tülümen, Metin, Thomas Hanemann, Michael J. Hoffmann, Rainer Oberacker, and Volker Piotter. "Process Development for the Ceramic Injection Molding of Oxide Chopped Fiber Reinforced Aluminum Oxide." Key Engineering Materials 742 (July 2017): 231–37. http://dx.doi.org/10.4028/www.scientific.net/kem.742.231.
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In this study, it was tried to develop a process chain for ceramic injection molding of Al2O3-chopped-fiber reinforced oxide-ceramic-matrix-composite. The feedstocks are compounded at 50 Vol. % filling degree of solid (Al2O3 μ-powder (Taimei Chemicals Co. Ltd.) and 3,2 mm chopped fibers (3M)), in which fiber content varies from 0 Vol. % to 100 Vol. %. As binder system, PE + Paraffin Wax + Stearic Acid are used. The ingredients are compounded in a kneader (Brabender) at 125°C and after the viscosity measurement in the high pressure capillary rheometer at 160°C and certain shear rates, the feedstock is injection molded (Battenfeld) at 160°C, which is followed by debinding process, including chemical (in n-Hexane) and thermal steps, and 2h sintering at different temperatures. Flow paths in the machinery parts, rheological properties of binding system, fiber content and the fiber orientation have significant effect on the flow behavior of the feedstock, fiber -orientation, -distribution & -length, which are crucial to understand the properties of end-parts like mechanical reinforcement of the fibers. The fibers in the sintered parts are ca. 200 μm in average length. The fibers in the feedstock show different orientations depending on the part-geometry and the green bodies have different densities depending on sintering temperature, amount of dispersant and fiber orientation.
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Gou, Yan Zi, Hao Wang, Ke Jian, Yong Cai Song, and Jun Wang. "Influence of Composition and Microstructure on the Mechanical Properties of SiC Ceramic Fibers." Materials Science Forum 816 (April 2015): 163–68. http://dx.doi.org/10.4028/www.scientific.net/msf.816.163.
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In this work, the influences of composition and microstructure on the mechanical properties and thermal stability of SiC ceramic fibers were investigated. XPS, XRD, SEM, and element analysis were used to analyze the elemental composition and structural morphology. The contents of oxygen and free carbon influence the crystallinity of SiC fibers, which inhibit the grain growth of β-SiC. The reduction of tensile strength of the fibers sintered under temperatures above 1700°C is attributed to the appearance of massive defects on the outer surface of the fibers, which can be overcome by the change of sintering conditions of the pyrolysis fibers.
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Naslain, R., and F. Christin. "SiC-Matrix Composite Materials for Advanced Jet Engines." MRS Bulletin 28, no. 9 (September 2003): 654–58. http://dx.doi.org/10.1557/mrs2003.193.
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AbstractSiC-matrix composites consist of ceramic fibers embedded in a silicon carbide matrix produced by gas-, liquid-, or solid-phase routes, yielding materials that differ in matrix crystallinity, residual porosity, and thermal properties. These composites can be highly engineered in terms of the nature of the reinforcement, the interphase used to control the fiber-matrix bonding, the matrix, and the seal coating used. SiC-matrix composites are refractory ceramics displaying outstanding mechanical and thermal properties at high temperature. Their durability in oxidizing atmospheres and under load exceeds 1000 h at temperatures of up to ∼1200°C. They have been used to fabricate different components of the hot zone of jet engines with significant weight savings and an increase in performance. This article reviews the state of the art in the processing, materials design, and properties of these composites as well as their applications in advanced jet engines.
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White, L. R., T. L. Tompkins, K. C. Hsieh, and D. D. Johnson. "Ceramic Filters for Hot Gas Cleanup." Journal of Engineering for Gas Turbines and Power 115, no. 3 (July 1, 1993): 665–69. http://dx.doi.org/10.1115/1.2906757.
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This paper reviews the properties of high-temperature ceramic fibers and relates why strength, thermal shock resistance, chemical inertness, and high-temperature capability are important properties for high-temperature filter media. The use of candle filters, fabric filters, and composite filters will be discussed for removal of particulates from hot gas streams in electrical power generation systems, metal refining, chemical processing, and Diesel engine exhaust applications.
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Stygienė, Laimutė, Sandra Varnaitė-Žuravliova, Aušra Abraitienė, Sigitas Krauledas, Julija Baltušnikaitė-Guzaitienė, and Ingrida Padleckienė. "Investigation of thermoregulation properties of various ceramic-containing knitted fabric structures." Journal of Industrial Textiles 50, no. 5 (April 16, 2019): 716–39. http://dx.doi.org/10.1177/1528083719842793.
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To ensure the thermal comfort during high physical activity, clothes must have good thermoregulation properties. Textiles containing ceramic additives, which are able to absorb and emit back the thermal energy from the human body, can be used to improve the thermal properties of the fabric. The aim of the research was to investigate the thermal and moisture management properties of different, three-layer knitted fabrics containing fibers impregnated with infrared-emitting ceramic particles. The thermal efficiency of the manufactured knits was characterised by the dynamics of accumulated/released heat generated by infrared rays and expressed as achieved steady-state surface temperature while and after the heating. Thermal resistance and liquid moisture management properties were investigated during the research as well. The elemental analysis of different pure bio-ceramic additives in yarns, used for development of knitted fabrics, was determined by X-ray fluorescence spectroscopy analysis. It was determined that heat accumulation is directly related to the calculated quantity of bio-ceramic additives in the knits. The obvious correlation between accumulated/released heat, thermal resistance, and the quantity of bio-ceramic additives in all investigated knitted structures was also investigated. Taking into account all the results obtained during the study of the thermoregulation properties, the optimal knitted structure, which could be comfortable for wearing next to the skin in cold weather, was selected.
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Jogl, Marcel, Pavel Reiterman, Ondřej Holčapek, Jaroslava Koťátková, and Petr Konvalinka. "RESIDUAL PROPERTIES OF FIBER-REINFORCED REFRACTORY COMPOSITES WITH A FIRECLAY FILLER." Acta Polytechnica 56, no. 1 (February 29, 2016): 27. http://dx.doi.org/10.14311/app.2016.56.0027.
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The aim of our study was to develop a composite material for industrial use that is resistant to the effect of high temperatures. The binder system based on aluminous cement was modified by adding finely-ground ceramic powder and metakaolin to reduce costs and also to reduce adverse effects on the environment due to high energy consumption for cement production. Additives were applied as a partial aluminous cement replacement in doses of 10, 20 and 30% by weight. The composites were evaluated on the basis of their mechanical properties and their bulk density after gradual temperature loading. The influence of basalt fibers and modifications to the binder system were studied at the same time. Basalt fibers were applied in doses of 0.5% and 2.0% by volume. The results confirmed the potential of the mineral additives studied here for practical applications, taking into account the residual mechanical parameters after thermal loading. The addition of ceramic powder reduced the bulk density by 5% for each 10% of cement substitution, but the residual values were very similar. The bulk density and the compressive strength were reduced when basalt fibers were applied, and the flexural strength was significantly increased in proportion to the fiber dosages. Metakaolin seems to be a more suitable additive than the ceramic powder that was applied here, because there was a significant increase in the mechanical parameters and also in the residual values of all properties that were studied.
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Liu, Hao, Xi Tang Wang, Zhou Fu Wang, and Bao Guo Zhang. "Effects of Al2O3 on the Structure and Properties of Calcium-Magnesium-Silicate Glass Fiber." Advanced Materials Research 450-451 (January 2012): 42–45. http://dx.doi.org/10.4028/www.scientific.net/amr.450-451.42.
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Calcium-magnesium-silicate glass fiber is a kind of candidate materials for aluminosilicate ceramic fiber in high temperature resistant field. However, the large thermal shrinkage limits its rapid development and industrial application in high temperature insulation field. It has been known that the shrinkage under high temperatures is mainly affected by the structure and crystallization mechanisms of glass fibers. Thus, Al2O3 was chosen as additive in the chemical composition of glass fiber to investigate the glassy network structure, crystallization and dissolution properties of calcium-magnesium-silicate glass fiber by DTA, XRD and ICP-AES techniques. The results show that with the addition of Al2O3, the glassy network structure was strengthened and the precipitation of crystals was inhibited for heat-treated fibers. As for the dissolution properties in physiological fluids, though the weight losses, changes of pH values and leached ions concentration lowered slightly with the addition of Al2O3 for the intensified network structure, fibers still present high dissolution rates.
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Tonoli, Gustavo Henrique Denzin, Sérgio Francisco dos Santos, José Antonio Rabi, Wilson Nunes dos Santos, and Holmer Savastano Junior. "Thermal performance of sisal fiber-cement roofing tiles for rural constructions." Scientia Agricola 68, no. 1 (February 2011): 1–7. http://dx.doi.org/10.1590/s0103-90162011000100001.
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Roofing provides the main protection against direct solar radiation in animal housing. Appropriate thermal properties of roofing materials tend to improve the thermal comfort in the inner ambient. Nonasbestos fiber-cement roofing components reinforced with cellulose pulp from sisal (Agave sisalana) were produced by slurry and dewatering techniques, with an optional addition of polypropylene fibers. Nonasbestos tiles were evaluated and compared with commercially available asbestos-cement sheets and ceramic tiles (frequently chosen as roofing materials for animal housing). Thermal conductivity and thermal diffusivity of tiles were determined by the parallel hot-wire method, along with the evaluation of the downside surface temperature. Cement-based components reinforced with sisal pulp presented better thermal performance at room temperature (25ºC), while those reinforced with sisal pulp added by polypropylene fibers presented better thermal performance at 60ºC. Non-asbestos cement tiles provided more efficient protection against radiation than asbestos corrugated sheets.
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El Yagoubi, Jalal, Jacques Lamon, and Jean Christophe Batsale. "Multiscale Modelling of the Influence of Damage on the Thermal Properties of Ceramic Matrix Composites." Advances in Science and Technology 73 (October 2010): 65–71. http://dx.doi.org/10.4028/www.scientific.net/ast.73.65.
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Ceramic matrix composites (CMC) are very attractive materials for structural applications at high temperatures. Not only must CMC be damage tolerant, but they must also allow thermal management. For this purpose heat transfers must be controlled even in the presence of damage. Damage consists in multiple cracks that form in the matrix and ultimately in the fibers, when the stresses exceed the proportional limit. Therefore the thermal conductivity dependence on applied load is a factor of primary importance for the design of CMC components. This original approach combines a model of matrix cracking with a model of heat transfer through an elementary cracked volume element containing matrix crack and an interfacial crack. It was applied to 1D composites subject to tensile ant thermal loading parallel to fiber direction in a previous paper. The present paper compares predictions to experimental results.
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Zach, Jiri, Martin Sedlmajer, and Jitka Hroudová. "Development of Building Elements with Thermal Insulation Filler Based on Secondary Raw Materials." Advanced Materials Research 649 (January 2013): 147–50. http://dx.doi.org/10.4028/www.scientific.net/amr.649.147.
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With increasing requirements for properties of envelope design in respect of thermal protection of buildings also requirements for building material properties have been growing. In case of ceramic shaped pieces for peripheral structures the way to further improvement of its thermal insulation properties is quite difficult. Generally thickness of interior groins can be reduced and its geometrical layout changed or the ceramics blocks dimensions increased and thus width of the masonry construction. Use of insulation filler integrated in block cavities is the alternative technology of production of insulation special shapes of high insulation properties. In these cases the ceramic fragment ensures the mechanical stability of the block and integrated insulation layer in smaller or bigger part (depending on its part) the thermal properties and eventually also the acoustic and insulation ones. The paper describes application possibilities of insulation materials based upon waste textile fibres as integrated layer in current masonry ceramic blocks of high utility properties.
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Dimitrijevic, M., M. Posarac, R. Jancic-Heinemman, J. Majstorovic, T. Volkov-Husovic, and B. Matovic. "Thermal shock resistance of ceramic fibre composites characterized by non-destructive methods." Processing and Application of Ceramics 2, no. 2 (2008): 115–19. http://dx.doi.org/10.2298/pac0802115d.
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Alumina based ceramic fibres and alumina based ceramic were used to produce composite material. Behaviour of composite ceramics after thermal shock treatments was investigated. Thermal shock of the samples was evaluated using water quench test. Surface deterioration level of samples was monitored by image analysis before and after a number of quenching cycles. Ultrasonic measurements were done on samples after quench tests. Dynamic Young modulus of elasticity and strength degradation were calculated using measured values of ultrasonic velocities. Strengths deterioration was calculated using the non-destructive measurements and correlated to degradation of surface area and number of quenches. The addition of small amount of ceramic fibres improves the strengths and diminishes the loss of mechanical properties of samples during thermal shock experiments.
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Ichikawa, Hiroshi. "High Performance SiC Fibers from Polycarbosilane for High Temperature Applications." Key Engineering Materials 352 (August 2007): 59–64. http://dx.doi.org/10.4028/www.scientific.net/kem.352.59.
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In recent years, it has been increasing in demand for high performance CMCs for high temperature application. CMCs are most promising materials for high temperature structural materials of gas turbines for aerospace and power generation. Mechanical performances of CMCs are highly dependent on properties of the reinforcement. The oxygen free SiC fiber (Hi-Nicalon) has been commercially produced by an electron beam curing process. And then the SiC fiber (Hi-Nicalon Type S) having stoichiometric SiC composition and high crystallinity was developed. Hi-Nicalon fiber has higher elastic modulus and thermal stability than Nicalon fiber. The Type S fiber has the highest elastic modulus and thermal stability and excellent creep resistance in three types of Nicalon family fibers. Recently, the Type S fibers as industrial products were developed and put on the market. The Type S (industrial version) fibers had a high tensile strength of 2.8 GPa, a high elastic modulus of 390 GPa. The Type S fiber retained a tensile strength of 2.2 GPa and an elastic modulus of 390 GPa after exposure at 1873 K. Moreover, the Type S fiber had outstanding creep resistance; the Type S fiber showed higher stress relaxation ratio than many other ceramic fibers after thermal exposure over 1673 K. The Type S fibers could be the best candidate for the reinforcement of CMCs. The fibers can be supplied about 30 kg per a month at present. Now, the Type S fiber/BN/SiC composites are being developed as the components of gas turbine for aerospace and land based power generation such as shrouds and combustors.
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Cao, Lintao, Xianming Shi, Xuran Liu, and Jianlin Wu. "Laboratory study on the properties of plastering mortar modified by feather fibers." Science and Engineering of Composite Materials 20, no. 3 (August 1, 2013): 293–99. http://dx.doi.org/10.1515/secm-2012-0065.
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AbstractThis laboratory study explores the development of plastering mortar modified by feather fibers, so as to lay the groundwork for utilizing poultry feathers in thermal-insulation materials and removing them from waste streams. The laboratory testing measured the consistency value, porosity, compressive strength and thermal conductivity of various cement mortar mixes as a function of feather fiber dosage. The experimental data were used to determine the appropriate weight fraction of feather fibers in the mortars for thermal insulation. The results indicate that the incorporation of feather fibers decreased the consistency value of fresh mortar and increased the surface roughness and porosity of hardened mortar. Under the investigated conditions, as the content of admixed fiber increased, both the compressive strength and thermal conductivity of hardened mortar decreased remarkably before leveling off. The desirable dosage of feather fibers falls in the range of 0.2–0.7% by mass of dry mixture.
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Ni, Xing Yuan, Ji Chao Wang, Guang Wu Liu, Zhi Hua Zhang, Jun Shen, Bin Zhou, and Guang Ming Wu. "Preparation and Properties of Super Insulation Material SiO2 Aerogel." Advanced Materials Research 516-517 (May 2012): 1531–35. http://dx.doi.org/10.4028/www.scientific.net/amr.516-517.1531.
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Nano-porous monolithic SiO2 aerogel as insulation material was prepared from silicon alkoxide as the precursor materials, followed by ethanol supercritical drying in this paper. In order to improve the mechanical properties of silica aerogel monoliths, the ceramic fibers were mixed in the pure aerogel, or integrating inorganic fiber materials as skeleton materials with low thermal conductivity supporting. Instron 5566, 5500R Material Testing Machine was used to measure the mechanical intensity. SEM was used to characterize the morphology of the silica aerogel monoliths. The thermal properties of the silica aerogels were determined by using the Hot Disk device. The results show that new type composite materials had a low effect on the thermal conductivities of the silica aerogel monoliths, but improved the mechanical intensity clearly. It made a great progress in the practical application of the SiO2 aerogel monoliths.
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Alhijazi, Mohamad, Babak Safaei, Qasim Zeeshan, Mohammed Asmael, Arameh Eyvazian, and Zhaoye Qin. "Recent Developments in Luffa Natural Fiber Composites: Review." Sustainability 12, no. 18 (September 17, 2020): 7683. http://dx.doi.org/10.3390/su12187683.
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Natural fiber composites (NFCs) are an evolving area in polymer sciences. Fibers extracted from natural sources hold a wide set of advantages such as negligible cost, significant mechanical characteristics, low density, high strength-to-weight ratio, environmental friendliness, recyclability, etc. Luffa cylindrica, also termed luffa gourd or luffa sponge, is a natural fiber that has a solid potential to replace synthetic fibers in composite materials in diverse applications like vibration isolation, sound absorption, packaging, etc. Recently, many researches have involved luffa fibers as a reinforcement in the development of NFC, aiming to investigate their performance in selected matrices as well as the behavior of the end NFC. This paper presents a review on recent developments in luffa natural fiber composites. Physical, morphological, mechanical, thermal, electrical, and acoustic properties of luffa NFCs are investigated, categorized, and compared, taking into consideration selected matrices as well as the size, volume fraction, and treatments of fibers. Although luffa natural fiber composites have revealed promising properties, the addition of these natural fibers increases water absorption. Moreover, chemical treatments with different agents such as sodium hydroxide (NaOH) and benzoyl can remarkably enhance the surface area of luffa fibers, remove undesirable impurities, and reduce water uptake, thereby improving their overall characteristics. Hybridization of luffa NFC with other natural or synthetic fibers, e.g., glass, carbon, ceramic, flax, jute, etc., can enhance the properties of the end composite material. However, luffa fibers have exhibited a profuse compatibility with epoxy matrix.
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Gupta, Vijay. "An Evaluation of the Interface Tensile Strength–Toughness Relationship." MRS Bulletin 16, no. 4 (April 1991): 39–45. http://dx.doi.org/10.1557/s0883769400057092.
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Mechanical properties of interfaces between dissimilar or similar materials (e.g., grain boundaries) have become the focal point of research in several fields, including composite materials (metal, ceramic and intermetallic matrix composites), tribology, and solid state devices. This is not surprising because the interfaces between dissimilar materials are sites for mechanical stress concentrations and often nucleate the overall failure process.Interfaces of interest in composite materials exist between fibers and their diffusion barrier coatings or between the fibers and the surrounding matrix material. In the field of tribology, interfaces exist between various types of functional (magnetic, conducting, optical, electrical), protective (thermal barrier, corrosion, wear resistant), or decorative coatings and their underlying substrates. And, finally, metal/ceramic interfaces are of interest in multilayer devices and magnetic disks and head technology. In all the above applications, mechanical properties of the interface (tensile and shear strength, toughness, etc.) often control the overall functionality of the coated part. Therefore, improving the mechanical properties of the interface for a prolonged life of the coated part is of fundamental interest. However, in ceramic and metal matrix composites, where the fiber/coating interface is used to deflect impinging cracks from the matrix, it is often desirable to impair the strength of the interface.
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Shestakov, A. M., N. I. Shvets, and V. A. Rosenenkova. "Study of preceramic compositions based on modified polycarbosilane and polyorganosilazanes." Industrial laboratory. Diagnostics of materials 87, no. 9 (September 24, 2021): 30–37. http://dx.doi.org/10.26896/1028-6861-2021-87-9-30-37.
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Ceramic matrix composites (CMC) exhibit increased crack resistance and resistance to mechanical and thermal shock impacts retaining at the same time the valuable properties of monolithic ceramics. Therefore, they are widely used as parts of heat-loaded elements of aviation and rocket technology, in nuclear power industry, etc. LPI-method (liquid polymer infiltration) of CMC production is based on the impregnation of a skeleton of ceramic fibers with an organosilicon polymer, formation of a preceramic matrix by polymer technology, and subsequent high-temperature pyrolysis resulting in formation of a reinforced ceramic matrix. Ceramics obtained from polymer precursors have a predominantly amorphous structure which determines its high thermal stability. Moreover, introduction of the nanosized particles of carbides, borides and nitrides of refractory metals (Zr, Ti, Hf) into the matrix of a ceramic composite stabilizes its amorphous structure up to temperatures of 1500 - 1600°C. We present the results of studying the preceramic compositions based on polycarbosilane and polyorganosilazanes modified with Hf and Ta atoms. It is shown that introduction of the modifying additives Hf and Ta into the polyorganosilazane composition shifts the curing interval of the compositions towards lower temperatures. The yield of the gel fraction is 73.3 and 82.7 wt.%, respectively. The weight loss of pyrolysate samples heated to 1400°C in air does not exceed 0.5%. The physical and mechanical properties, as well as the thermal oxidative stability of novel ceramic composite materials obtained on the base of the studied compositions and carbon reinforcing filler are analyzed. It is shown that the density of CMC samples increases by 1.5 times with an increase in the number of impregnation cycles and reaches the maximum value of 1950 kg/m3 with five impregnation cycles of the filler with a composition based on polyorganosilazane modified with Ta. The results obtained can be used in the development of new CMCs.
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Dimitrijevic, Marija, Djordje Veljovic, Milica Posarac-Markovic, Radmila Jancic-Heinemann, Tatjana Volkov-Husovic, and Milorad Zrilic. "Mechanical properties correlation to processing parameters for advanced alumina based refractories." Science of Sintering 44, no. 1 (2012): 25–33. http://dx.doi.org/10.2298/sos1201025d.
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Alumina based refractories are usually used in metallurgical furnaces and their thermal shock resistance is of great importance. In order to improve thermal shock resistance and mechanical properties of alumina based refractories short ceramic fibers were added to the material. SEM technique was used to compare the microstructure of specimens and the observed images gave the porosity and morphological characteristics of pores in the specimens. Standard compression test was used to determine the modulus of elasticity and compression strength. Results obtained from thermal shock testing and mechanical properties measurements were used to establish regression models that correlated specimen properties to process parameters.
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Xiong, Xiaoshuang, Shirley Z. Shen, Lin Hua, Jefferson Z. Liu, Xiang Li, Xiaojin Wan, and Menghe Miao. "Finite element models of natural fibers and their composites: A review." Journal of Reinforced Plastics and Composites 37, no. 9 (February 6, 2018): 617–35. http://dx.doi.org/10.1177/0731684418755552.
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Finite element method has been widely applied in modeling natural fibers and natural fiber reinforced composites. This paper is a comprehensive review of finite element models of natural fibers and natural fiber reinforced composites, focusing on the micromechanical properties (strength, deformation, failure, and damage), thermal properties (thermal conductivity), and macro shape deformation (stress–strain and fracture). Representative volume element model is the most popular homogenization-based multi-scale constitutive method used in the finite element method to investigate the effect of microstructures on the mechanical and thermal properties of natural fibers and natural fiber reinforced composites. The representative volume element models of natural fibers and natural fiber reinforced composites at various length scales are discussed, including two types of geometrical modeling methods, the computer-based modeling method and the image-based modeling method. Their modeling efficiency and accuracy are also discussed.
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Abas, Falak O., and Raghad Usama Abass. "Study thermo-mechanical properties of polyester composite reinforced by ceramic particles, SiC." MATEC Web of Conferences 225 (2018): 01021. http://dx.doi.org/10.1051/matecconf/201822501021.
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Development of the Polymer Composites with natural fibers and fillers as a sustainable alternative material for some engineering applications, particularly in aerospace applications and automobile applications are being investigated. Lightweight and biodegradability and low cost Polyester composites are synthesised with an addition of Silicon carbide (SiC) particles by varying weight percentage (0, 3, 6, 10, 13, and 16 wt. %) respectively by using hand- layup technique followed by cold moulding. The prepared specimens were cut according to ASTM standard to determine hardness, impact strength, bending distortion and thermal conductivity properties. Afterward, the thermal and mechanical properties of all the unfilled and particulate filled composites are also evaluated for structural applications, i.e., hardness, impact strength, bending distortion, are determined with the change in filler content to notice the behaviour of composite material subjected to loading in addition to thermal conductivity property. Thermo-mechanical properties of the material are measured with the help of testing machines above according to their ASTM. It is found that the strength properties are greatly influenced by addition of this ceramic filler. Also shows that the thermal and mechanical properties of SiC-filled polyester composites are better than unfilled base composites
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Fatma, Naiiri, Lamis Allègue, Mehdi Salem, Redouane Zitoune, and Mondher Zidi. "The effect of doum palm fibers on the mechanical and thermal properties of gypsum mortar." Journal of Composite Materials 53, no. 19 (March 26, 2019): 2641–59. http://dx.doi.org/10.1177/0021998319838319.
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The main objective of this paper is the evaluation of the possibility of using a gypsum mortar reinforced with doum palm fibers as thermal insulators in building material. Several composite configurations with three sizes and five-weight ratios (from 0.5% to 2.5%) of doum palm fiber were prepared for mechanical and thermo-physical characterization. Generally, natural fibers are affected by the alkali environment of gypsum mortar. To overcome this problem, doum palm fibers were treated with a NaOH solution of 1% concentration to enhance their resistance against chemical degradation. Chemical treatment of fiber removes some hemicellulose and lignin and tends to make the fiber more homogenous, which enhances fiber–matrix interfacial properties. In addition, the mechanical properties of the specimens were tested after 7 days, 28 days and 1 year of curing in normal conditions. The obtained results show an improvement in the mechanical performance of composites reinforced with treated fibers. In fact, better results were obtained for gypsum mortar reinforced with treated reinforcement seive2 for the value of 1% of fibers. It was also noticed that NaOH treatment has an influence on the thermal conductivities. In fact, the use of treated doum palm fibers as reinforcement in gypsum mortar seems to be an alternative natural material to be used as a thermal insulator material.
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HE, YEDONG, KUN ZHANG, LIANGJIAN LI, and DEREN WANG. "NANO-/MICRO-COMPOSITE CERAMIC COATINGS PREPARED BY THERMAL PRESSURE FILTRATION OF SOL-GEL PAINTS." International Journal of Modern Physics B 20, no. 25n27 (October 30, 2006): 4649–54. http://dx.doi.org/10.1142/s0217979206041835.
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A novel coating technique, thermal pressure filtration of sol-gel paints (TPFSP), has been developed to prepare nano-/micro-composite ceramic coatings with controllable thickness, structure, and excellent high temperature properties. In this paper, the fabrication of two typical coatings, nano-/micro- Al 2 O 3- Y 2 O 3 composite coating and Al 2 O 3· SiO 2 fibers reinforced nano- ZrO 2-8wt.% Y 2 O 3 composite coating was demonstrated and their structures and properties were studied.
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Ji, Ru, Xi Dong Wang, Zuo Tai Zhang, and Li Li Liu. "Performance Test and Research of Ceramic Fiberboard." Applied Mechanics and Materials 488-489 (January 2014): 36–39. http://dx.doi.org/10.4028/www.scientific.net/amm.488-489.36.
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Ceramic fiber has great refractory and insulating ability. The coefficient of thermal conductivity is a significant characteristic of the fiber insulation materials, and shows the material thermal capacity. This paper not only research basic properties of ceramic fiberboard, but also focus on the influence factors of the effective thermal conductivity which include bulk density, temperature and moisture content.
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Gadow, Rainer, and Patrick Weichand. "SiOC Composite Structures for Intermediate Service Temperatures with Increased Friction Properties." Advances in Science and Technology 88 (October 2014): 15–20. http://dx.doi.org/10.4028/www.scientific.net/ast.88.15.
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Polymer Matrix Composites (PMC) are often used in lightweight applications due to their excellent mechanical properties combined with a low density. The manufacturing technologies are fully developed and raw materials are cheap. The limiting factor of these reinforced polymers is the maximum service temperature. Ceramic Matrix Composites (CMC) are suitable for service temperatures up to 1500 °C and more. These composites are composed of ceramic matrices combined with ceramic fibers based on alumina or silicon carbide. This class of composites is handicapped by the high cost of processing and raw materials and therefore only attractive for applications in astronautics and military aviation. Composite materials, bridging the gap between PMC and CMC, are manufactured by the use of polysiloxanes, carbon-and basalt fibers. Such competitive free formable Hybrid-composites are capable for service temperatures up to 800 °C in oxidative atmosphere. In order to make the material attractive also for series applications, manufacturing technologies like filament wet winding, Resin Transfer Moulding (RTM) or pressing techniques are employed. Beside the improved thermal resistivity in comparison to reinforced polymers and light metals, a major benefit of SiOC composites is investigated in the field of friction materials. The excellent properties in wear resistance and an adjustable coefficient of friction make it an interesting alternative for CFC and CMC.
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Lin, Wan-Qing, Yu-Xuan Zhang, and Hui Wang. "Thermal conductivity of unidirectional composites consisting of randomly dispersed glass fibers and temperature-dependent polyethylene matrix." Science and Engineering of Composite Materials 26, no. 1 (January 28, 2019): 412–22. http://dx.doi.org/10.1515/secm-2019-0024.
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AbstractThis extensive study investigated the influence of microstructure on the effective transverse thermal conductivity of unidirectional glass fiber reinforced composites, in which the fibers are randomly dispersed and the thermal conductivity of polyethylene matrix is a function of test temperature. The microstructure is characterized by parameters such as the number of fibers, fiber volume fraction, fiber size, fiber arrangement and thermal property contrast. Firstly, a simple algorithm is developed to automatically generate closest-to-real random array of fibers in unit cell to reconstruct the composite microstructure. Then, the established two-dimensional random two-component composite unit cell is solved using finite element simulation and the obtained effective thermal conductivities are compared with the theoretical predictions and the experimental results. Subsequently, the effects of microstructure parameters and test temperature are investigated, respectively. It is found that the finite element predicted properties are in very good agreement with the experimental predictions, while they are always lower than the analytically predicted properties. These results can find applications in the design of composite materials taking into account the fiber distribution morphology.
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Alikhani, Hossein, Fatemeh Sharifzadeh, and Hadi Khoramishad. "The mechanical and physical properties of nylon 6/glass fiber-reinforced hybrid composites manufactured by thermal and ultraviolet-cured pultrusion methods." Journal of Composite Materials 54, no. 21 (February 13, 2020): 2899–912. http://dx.doi.org/10.1177/0021998320906007.
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In this study, the effect of hybridizing glass fiber-reinforced polymer composites with nylon 6 fibers on the physical and mechanical properties of composites was investigated experimentally. The ultraviolet-cured and thermal pultrusion methods were employed for manufacturing the glass fiber-reinforced polymer and hybrid composite rods containing different volume percentages of nylon 6 fibers at low and high temperatures. The effects of the nylon 6 fibers and the pultrusion methods were investigated on the curing degree, the void content, the diameter expansion, the surface characteristics, and the quasi-static tensile and Charpy impact properties of the composite rods. The ultraviolet-cured hybrid composites showed superior mechanical properties than the thermally cured samples indicating the sensitivity of nylon 6 fibers to high-temperature curing. Moreover, the curing speed of ultraviolet-cured pultrusion was significantly higher than the thermal pultrusion. Delamination and fiber pull-out were the dominant damage mechanisms in the hybrid composites due to the low interfacial strength between the nylon 6 fibers and matrix.
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Li, Weiwei, Lei Liu, and Bin Shen. "The fabrication and properties of short carbon fiber reinforced copper matrix composites." Journal of Composite Materials 45, no. 24 (April 26, 2011): 2567–71. http://dx.doi.org/10.1177/0021998311401108.
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Short carbon fibers (SCFs) reinforced copper matrix composites, fiber volume fraction of which ranged from 10% to 30%, were prepared by electroless copper plating plus cold press and sintering technique. SCFs were copperized directly by electroless plating using hypophosphite as reducing agent. The effects of SCFs volume fraction on mechanical, thermal, and electrical properties of the composites were discussed. The results indicated that the microhardness and thermal expansion property of Cu/SCFs composites increased with increasing fibers content, owing to the high strength of SCF. However, thermal conductivity and electrical conductivity reversed, it was attributed to the performance of carbon fiber itself; furthermore, more defects and interfaces in the matrix acted as barriers to heat and electronic transfer.
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Duo, Yi, Sophie Costil, Pierre Pfeiffer, and Bruno Serio. "Embedding properties of optical fibers integrated into ceramic coatings obtained by wire flame thermal spray." Smart Materials and Structures 24, no. 3 (February 19, 2015): 035027. http://dx.doi.org/10.1088/0964-1726/24/3/035027.
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Ishikawa, Toshihiro. "SA-Tyrannohex-Based Composite for High Temperature Applications." Advances in Science and Technology 71 (October 2010): 118–26. http://dx.doi.org/10.4028/www.scientific.net/ast.71.118.
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To modify the relatively low fracture toughness of monolithic ceramics, the incorporation of long ceramic fibre within a matrix material has been extensively performed. In this case, as cracks form in the matrix material and approach the fibres, they will be deflected at the interface between the fibre and the matrix. We developed another approach toward improving the toughness of ceramics involving the creation of a textured internal structure within the ceramic itself, similar in some respects to the fibrous structure of wood. Actually, we developed a tough ceramic, which consists of a highly ordered, close-packed structure of very fine hexagonal columnar fibres with a thin interfacial carbon layer between fibres. The interior of the fibre element was composed of sintered beta-silicon carbide crystal. This concept is fundamentally different from that described previously, in that it is extremely difficult to distinguish separate “fibre” and “matrix” phases in the traditional composite sense. The toughness of the material in this case derives from the tremendous amount of interface area created within the internal structure through the close packing of the hexagonal columnar fibres. Furthermore, this ceramic also achieved the excellent high temperature properties, high thermal conductivity and low density. These properties will make it very attractive for replacement of heavy metal super alloy components.
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Yi, Li-Fu, Takashi Yamamoto, Tetsuhiko Onda, and Zhong-Chun Chen. "Microstructure and thermal properties of nickel-coated carbon fibers/aluminum composites." Journal of Composite Materials 54, no. 19 (January 10, 2020): 2539–48. http://dx.doi.org/10.1177/0021998319899154.
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Electroless nickel-coated carbon fibers/aluminum composites were prepared by spark plasma sintering, and the effect of nickel coating on microstructure and thermal properties of the composites has been investigated. Nickel coating on carbon fibers resulted in more homogeneous distributions of carbon fibers in aluminum matrix, higher relative density of carbon fibers/aluminum composites, and stronger interfacial bonding between carbon fibers and aluminum. Microstructural observations exhibited that the majority of carbon fibers were randomly distributed on the sections (X-Y direction) perpendicular to spark plasma sintering pressing direction (Z direction), thus leading to an anisotropic behavior in thermal conductivity of the composites. The thermal conductivity values in the X-Y direction of the carbon fibers/aluminum composites were much higher than those in the Z direction. As a result, the nickel-coated carbon fibers/aluminum composites with a nickel-coating thickness of ∼0.2 µm showed higher thermal conductivity and lower coefficient of thermal expansion values in comparison with those of the uncoated carbon fibers/aluminum samples.
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Panicker, Arun M., Rose Maria, KA Rajesh, and TO Varghese. "Bit coir fiber and sugarcane bagasse fiber reinforced eco-friendly polypropylene composites: Development and property evaluation thereof." Journal of Thermoplastic Composite Materials 33, no. 9 (January 10, 2019): 1175–95. http://dx.doi.org/10.1177/0892705718820403.
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Waste natural fibers, bit coir fiber residue of traditional coir industries, and sugarcane bagasse fibers were subjected to chemical modifications via alkaline steam explosion treatments toward the extraction of reinforcing fibers with better compatibility and reinforcing characteristics in the polymer matrix. The treated fibers were utilized in the fabrication of composites with polypropylene (PP) as the base polymer with the aid of maleic anhydride–grafted PP as the compatibilizer. Percent composition of fiber in the composites was decided to facilitate maximum replacement of the matrix and further applicability in large-scale continuous polymeric production processes. Mechanical, thermal, and morphological characterization of the composites reveals the best composition to be of 30% composition, in the added view of maximum replacement of polymer matrix with the reinforcing filler, retention of requisite properties, reduced cost of manufacture and inventory, and reduction in the carbon footprint per unit dimensions in comparison with the wholly polymer component. The thermal properties of coir fiber-reinforced composites showed good improvement up to 134.5°C increase in onset degradation temperature while retaining matrix properties for sugarcane bagasse-reinforced composites.
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Hu, Wei, Minh-Tan Ton-That, Johanne Denault, and Christian Belanger. "Characterization of polypropylene composites reinforced with flax fibers treated by mechanical and alkali methods." Science and Engineering of Composite Materials 18, no. 1-2 (June 1, 2011): 79–85. http://dx.doi.org/10.1515/secm.2011.011.
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AbstractFlax is a type of natural fiber widely used as reinforcing materials for polymer composites. The commercially available flax fibers in Canada consist of a significant amount of shive and other impurities, which could act as stress concentration regions to negatively affect the mechanical property of composites. In this study, the shive was manually removed from the commercial flax fibers by screening and combing to obtain different shive contents from 0 to 30 wt%. By contrast, the obtained flax fibers were further treated with alkaline solution. The fibers obtained from mechanical and alkali treatment were compared on their thermal and mechanical properties. As expected, it was found that the thermal stability and mechanical properties of the flax reinforced polypropylene composites increased significantly with the removal of the shive content. However, the alkali treatment on flax fiber did not further improve the composites properties. The possible reason was that the proper mechanical treatment (screening and combing) prior to alkaline treatment effectively loosened the fiber bundles for better single fiber separation in matrix and significantly removed the impurities, thus the effect of alkaline treatment did not become obvious.
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Farsani, Reza Eslami, and Ali Shokuhfar. "Carbon Fiber-Reinforced Composites in Automotive Engine." Defect and Diffusion Forum 312-315 (April 2011): 341–45. http://dx.doi.org/10.4028/www.scientific.net/ddf.312-315.341.
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In this article the last findings of composites with polymer, metal and ceramic matrices containing carbon fibers and their applications in internal combustion engines in the world beside their advantages and superiorities in comparison with common industrial materials are investigated. Afterwards, the position of these materials in automotive engines in Iran is analyzed. Researches show that carbon fibers-reinforced composites due to unique properties (including high specific strength and specific modulus, low thermal expansion coefficient, high fatigue strength, and high thermal stability) can replace common structural materials in different engine parts (such as, casing, different components, cylinder lining, and etc.). Applying these composites will result in weight reduction and consequently fuel consumption reduction, less pollution, better function and efficiency, and more lifetimes. Of course one should consider that there is a vast potential for application and development of composites in automotive engine, which will become in practice by complementary researches through time. Due to novelty of this technology in the world and also the lack of carbon fibers production and insufficient knowledge of production and application of carbon fiber composites in Iran, this issue has not been seriously investigated.
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Baranowska, Agata, Magdalena Leśniak, Marcin Kochanowicz, Jacek Żmojda, Piotr Miluski, and Dominik Dorosz. "Crystallization Kinetics and Structural Properties of the 45S5 Bioactive Glass and Glass-Ceramic Fiber Doped with Eu3+." Materials 13, no. 6 (March 12, 2020): 1281. http://dx.doi.org/10.3390/ma13061281.
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An investigation of the crystallization kinetics of 45S5 Bioglass® using differential scanning calorimetry is presented in this paper. Thermal analysis was performed using the Friedman method. The activation energy and the Avrami index were calculated. The glass samples were subjected to additional controlled heat treatment at 620 °C in order to obtain bioactive glass-ceramics with enhanced mechanical properties. X-ray powder diffraction (XRD) measurements indicated the formation of the glass-ceramic structures of three cyclosilicates: Na4Ca4(Si6O18) or Na6Ca3(Si6O18) or Na16Ca4(Si12O36). Based on middle infrared region (MIR) results, it can be concluded that the crystalline phase present in the tested materials was Na6Ca3(Si6O18) (combeite). Material was doped with Eu3+ ions, which act as a spectroscopic probe for monitoring the structural changes in the glass matrix. The decreasing value of the fluorescence intensity radio parameter indicated symmetry around the europium ions and, thus, the arrangement of the glass structure. The bioactive properties of the examined glass-ceramics were also determined. The bioactive glass fibers doped with Eu3+ were manufactured using two different methods. Its structural and luminescent properties were examined.