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Carbon Fiber Composites (carbon + fiber_composite)
Selected AbstractsProcessing and Tribological Properties of Si3N4/Carbon Short Fiber CompositesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2003Hideki Hyuga Si3N4/carbon fiber composites were fabricated using several types of fiber. All the composites had higher fracture toughness compared with monolithic Si3N4 ceramics. Tribological properties were investigated by a ball-on-disk method under unlubricated conditions. The composite containing fibers with a high orientation of graphite layers and high graphite content indicated a low friction coefficient. It was identified, by Raman spectroscopy, that graphite was transferred from the composite to the Si3N4 ball of the counterbody during the wear test. This transferred layer was effective for producing the low friction behavior of the composite. [source] Comparison of mechanical properties of epoxy composites reinforced with stitched glass and carbon fabrics: Characterization of mechanical anisotropy in composites and investigation on the interaction between fiber and epoxy matrixPOLYMER COMPOSITES, Issue 8 2008Volkan Çeçen The primary purpose of the study is to evaluate and compare the mechanical properties of epoxy-based composites having different fiber reinforcements. Glass and carbon fiber composite laminates were manufactured by vacuum infusion of epoxy resin into two commonly used noncrimp stitched fabric (NCF) types: unidirectional and biaxial fabrics. The effects of geometric variables on composite structural integrity and strength were illustrated. Hence, tensile and three-point bending flexural tests were conducted up to failure on specimens strengthened with different layouts of fibrous plies in NCF. In this article, an important practical problem in fibrous composites, interlaminar shear strength as measured in short beam shear test, is discussed. The fabric composites were tested in three directions: at 0°, 45°, and 90°. In addition to the extensive efforts in elucidating the variation in the mechanical properties of noncrimp glass and carbon fabric reinforced laminates, the work presented here focuses, also, on the type of interactions that are established between fiber and epoxy matrix. The experiments, in conjunction with scanning electron photomicrographs of fractured surfaces of composites, were interpreted in an attempt to explain the failure mechanisms in the composite laminates broken in tension. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers [source] Thermomechanical characteristics of benzoxazine,urethane copolymers and their carbon fiber-reinforced compositesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2009Sarawut Rimdusit Abstract Copolymers of polybenzoxazine (BA-a) and urethane elastomer (PU) with three different structures of isocyanates [i.e., toluene diisocyanate (TDI), diphenylmethane diisocyanate, and isophorone diisocyanate], were examined. The experimental results reveal that the enhancement in glass transition temperature (Tg) of BA-a/PU copolymers was clearly observed [i.e., Tg of the BA-a/PU copolymers in 60 : 40 BA-a : PU system for all isocyanate types (Tg beyond 230°C) was higher than those of the parent resins (165°C for BA-a and ,70°C for PU)]. It was reported that the degradation temperature increased from 321°C to about 330°C with increasing urethane content. Furthermore, the flexural strength synergism was found at the BA-a : PU ratio of 90 : 10 for all types of isocyanates. The effect of urethane prepolymer based on TDI rendered the highest Tg, flexural modulus, and flexural strength of the copolymers among the three isocyanates used. The preferable isocyanate of the binary systems for making high processable carbon fiber composites was based on TDI. The flexural strength of the carbon fiber-reinforced BA-a : PU based on TDI at 80 wt % of the fiber in cross-ply orientation provided relatively high values of about 490 MPa. The flexural modulus slightly decreased from 51 GPa for polybenzoxazine to 48 GPa in the 60 : 40 BA-a : PU system. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Novel polyurethane elastomer continuous carbon fiber composites: Preparation and characterizationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007Borda Abstract Preparation and characterization of novel polyurethane (PUR),carbon fiber (CF) composites are reported. The reinforcement of PUR elastomers was achieved using unidirectional continuous CFs with different coatings (uncoated and epoxy and polyester resin coatings) by applying molding for the preparation of PUR-CF composites. Considerable reinforcement of PUR was attained even at relatively low CF content, e.g., maximum stress and Young's modulus of PUR-CF composite at CF content 3% (m/m) were found to be 3,5 and 4,10 times higher than those of the PUR-matrix, respectively. In addition, a linear relationship between the Young's modulus and the CF content was found as well as linear variation of maximum stress with the CF content was also observed. The adhesion of CF to the PUR-matrix was strong in each case as concluded from the strain,stress and the scanning electron microscopy (SEM) investigations. However, the extent of reinforcement of PUR at a given CF content was found to depend greatly on the coatings of CF, and increased in the following order: epoxy resin < polyester resin < uncoated. The effect of the coating of CF on the reinforcement of PUR is also discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 287,292, 2007 [source] Anomalies, influencing factors, and guidelines for DMA testing of fiber reinforced compositesPOLYMER COMPOSITES, Issue 7 2009Gowthaman Swaminathan This study systematically assessed the measurement of dynamic properties of a range of fiber reinforced composite materials using dynamic mechanical analysis (DMA) instrument. The discrepancy in the moduli from DMA to ASTM tests was investigated. The study showed that proper specimen preparation, maintaining appropriate aspect ratio (span to thickness ratio) to reduce the transverse shear deformation, and sufficient loading are critical to measure correct properties from DMA test. The guidelines on aspect ratio and loading for plastics to high-modulus carbon fiber composites are presented as a design chart and equations, respectively. The study also found that the glass transition temperature (Tg) was independent of specimen aspect ratio and Tg is lower for multidirectional composites when compared with its unidirectional composites. The particle interleaved T800H/3900-2 composite showed two glass transition temperatures (140 and 198°C), the lower value is due to the effect of interleaving by thermoplastic particles, and the higher value is the Tg of its base matrix. This lowering of Tg would have significant effect on the application temperature of the material. This phenomenon was not observed here to fore in the literature. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers [source] Tensile properties of carbon filled liquid crystal polymer composites,POLYMER COMPOSITES, Issue 1 2008Jason M. Keith Electrically and thermally conductive resins can be produced by adding carbon fillers. Mechanical properties such as tensile modulus, ultimate tensile strength, and strain at ultimate tensile strength are vital to the composite performance in fuel cell bipolar plate applications. This research focused on performing compounding runs followed by injection molding and tensile testing of carbon filled Vectra A950RX liquid crystal polymer composites. The four carbon fillers investigated included an electrically conductive carbon black, thermocarb synthetic graphite particles, and two carbon fibers (Fortafil 243 and Panex 30). For each different filler type, resins were produced and tested that contained varying amounts of these single carbon fillers. The carbon fiber samples exhibited superior tensile properties, with a large increase in tensile modulus over the base polymer, and very low drop in the ultimate tensile strength as the filler volume fraction was increased. The strain at the ultimate tensile strength was least affected by the addition of the Panex carbon fiber but was significantly affected by the Fortafil carbon fiber. In general, composites containing synthetic graphite did not perform as well as carbon fiber composites. Carbon black composites exhibited poor tensile properties. POLYM. COMPOS., 29:15,21, 2008. © 2007 Society of Plastics Engineers [source] Impact of in-line atmospheric plasma fluorination of carbon fibers on the performance of unidirectional, carbon fiber-reinforced polyvinylidene fluorideADVANCES IN POLYMER TECHNOLOGY, Issue 2 2010Siti-Ros Shamsuddin Abstract Unidirectional, carbon fiber-reinforced polyvinylidene fluoride (PVDF) composites were manufactured using a powder impregnation process with integrated in-line continuous atmospheric plasma fluorination of carbon fibers to produce unidirectional carbon fiber/PVDF tapes with a fiber volume fraction of 60 ± 2%. Carbon fiber/PVDF tapes were processed into composite laminate test specimens by compression moulding and interface-dominated composite properties were studied. Short-beam shear test results showed an improvement of up to 70% for the composite laminates containing atmospheric plasma-fluorinated T700 carbon fibers with a fluorine content of 3.7 at. %, as determined by X-ray photoelectron spectroscopy. The flexural strength and modulus of the laminated carbon fiber/PVDF composites containing APF-treated T700 carbon fibers also increased by 45% and 38%, respectively. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:86,97, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20175 [source] | ||||||||||