Papers by Keyword: Carbon Fiber

Abstract: A curing system has been developed for obtaining high-strength compositions matrix, which is used in the production of composites based on reinforced carbon fiber using prepreg technology with a curing temperature of . A technology has been developed for combining an epoxy oligomer with a curing agent and modifier. The pot life of the prepared prepregs is at least 15 days.

Abstract: The paper investigates the processes of carbon fiber surface treatment and their influence on the properties of polyetheretherketone composites. It has been shown that preliminary thermal activation of carbon fiber followed by treatment with a dressing agent - polyhydroxyether makes it possible to create polyetheretherketone composite carbon-filled materials with an increased level of physical and mechanical properties.

Abstract: The study of the properties of PEEK blends with different melt flow rate (MFR) and carbon-filled composites based on them was carried out. It was found that with an increase in the relative difference in the MFR of the blended PEEKs, there is an increase in the deviation of the experimental MFR values from the additive ones. Up to a relative difference in the MFR of the components equal to 60%, the blends obey the additivity rule. It is shown that the achievement of a certain MFR value by blending polymers with different viscosities leads to the production of materials with similar properties. Carbon-filled composites based on PEEK blends also demonstrate very similar rheological, mechanical and thermal properties, which indicates the effectiveness of the method of blending PEEKs with different viscosities to achieve the required rheological properties.

Abstract: The relevance of the search for scientifically grounded tools, with the help of which it is possible to ensure the growth of crack resistance and strength of foam concrete, is noted. The systemic need of the building complex for energy-and resource-saving operationally reliable building materials is emphasized. The positive influence of the surface energy potential of the fibrous fiber of polymer and carbon composition on the possibility of forming an improved structure of the cement stone in the composition of the interpore partitions of foam concrete has been scientifically substantiated. The article provides information on the foam mixtures formulation and the timing of their hardening. The scans of the investigated materials’ X-ray diffraction patterns and the identification table of the detected hydration neoplasms of the cement stone are presented. The scientific substantiation reliability is experimentally confirmed by the results of the analysis performed, from which it follows that all foam concretes contain quartz, portlandite, hydro-aluminates and calcium hydro-silicates. It has been established that the introduction of fiber into the foam mixture formulation creates the prerequisites for the appearance of such varieties of the hydrated silicate phase as nekoite, which has a fibrous structure at the nanoscale, and foshagite, which has an acicular structure of crystals with increased hardness. The listed mineral hydrated new formations of cement stone, due to their individual properties, should contribute to the foam concrete operational properties’ improvement.

Abstract: Solutions with various concentrations of TiO₂ were obtained and studied. The morphology of the carbon fiber with TiO₂ coatings was investigated. The TiO₂ concentration significantly effects on viscosity and coatings formed on carbon fibers. The relationship between TiO₂ sol concentration and the mass oxide on the surface of carbon fibers was studied.

Abstract: In this article we investigated properties of elementary carbon fibers after their activation and subsequent deposition of thin layers of metal coatings on their surface. For deposition we used copper, titanium and stainless steel. We investigated influence of various technologies of preliminary processing of the fiber surface on the value of the adhesion strength of the metal coating to the carbon tape and on the mechanical properties of elementary fibers. We established that the strength of carbon plastics at interlayer shear increases by 10-30% when using carbon tapes and fabrics with a metal coating.

Abstract: This paper studies deployable elements which are used in satellites and different terrestrial antenna devices. Many deployable elements are made from steel or thermoset polymer composite materials and have the following disadvantages like length limitation of deployable elements, labour intensity of manufacturing process of deployable elements etc. For this purpose a deployable tube boom element was chosen and a forming method for manufacturing deployable tube element from thermoplastic polymer composite material was developed.

Abstract: Experimental studies of bending deformation of carbon - and fiberglass samples after 8-month exposure in full-scale conditions were performed and the modulus of transverse elasticity was determined. It was found that the influence of the external environment on fiberglass samples is more significant. For carbon fiber, there was an average decrease of 7.1%, and for fiberglass-by 14%. Modification of samples in ultrahigh frequencies (UHF) electromagnetic field reduces the negative influence of the environment: the values of the transverse elastic modulus of carbon fiber and fiberglass samples are reduced by 5% and 11%, respectively. It is shown that the UHF electromagnetic field in rational modes can increase the modulus of transverse elasticity of carbon fiber by (27-30)%, fiberglass – by (20.8-25.6)% with a significant increase in the uniformity of this parameter. Experimental studies of the bending deformation of carbon-and fiberglass specimens after 8-month exposure in natural conditions have been carried out, and the shear elastic modulus has been determined. It has been established that the influence of the external environment on fiberglass samples is more significant. For carbon fiber reinforced plastic, a decrease was noted on average by 7.1%, for fiberglass - by 14%. Modification of samples in a microwave electromagnetic field helps to reduce the negative influence of the external environment: the values ​​of the shear modulus of the prototypes of carbon fiber reinforced plastic and fiberglass are reduced by 5% and 11%, respectively. It is shown that the microwave electromagnetic field in rational modes allows increasing the transverse elastic modulus of carbon fiber reinforced plastic by (27-30)%, fiberglass - by (20.8-25.6)% with a significant increase in the uniformity of this parameter.

Abstract: To prepare a kind of Fe-Cu-based friction material with good friction performance and wear resistance, and apply it to the brake structure of automobile machinery, the powder metallurgy method is used to prepare the friction materials in the standard with 4% Ni, 4% Mo and 2% Sn as the auxiliary material, SiC, Al₂O₃, and zircon sand as the basic friction material, 8% graphite and 3% MoS₂ as the lubricating component. Meanwhile, 50% Fe and 20% Cu is used for the preparation of friction materials. The friction and wear resistance can be increased by increasing the carbon fiber content of 0-8% concentration of the material. The results show that the friction coefficient of the Fe-Cu-based friction material is relatively gentle after the addition of 2% carbon fiber, and the compactness peaks, reaching 93.3%. Its shear strength and impact strength peak, which are 37.42Mpa and 6.7J/cm² respectively. 4% carbon fiber material with a hardness of 120.2 HV is the hardest one, followed by 2% carbon fiber material with a hardness of 118.1 HV. Added with 2% carbon fiber, the abrasion amount of the friction-based material is 0.0027 g at room temperature and-0.0008 g at 400°C after 60 minutes respectively. With all indicators considered, the result shows that the friction performance and wear resistance of Fe-Cu-based friction materials can be increased by adding 2% carbon fiber during the preparation of basic friction materials.

Abstract: This study is to explore the changes in the performance of sports equipment under the action of carbon fiber reinforced epoxy composites. This paper studies the effects of carbon fiber reinforced epoxy composites in pole vault, bicycle, and tennis. The research results show that the performance of sports equipment based on carbon fiber reinforced epoxy composite materials has been greatly improved, with outstanding effects in terms of thermal properties, interface properties, mechanical properties, and fatigue resistance. Carbon fiber reinforced epoxy composite material damage expansion is divided into five stages: matrix cracking, interfacial degumming, delamination, fiber fracture, fracture. Therefore, carbon fiber reinforced epoxy composite materials are comprehensive for the improvement of sports equipment, which has greatly promoted the further development of sports. Carbon fiber reinforced epoxy composite materials can be promoted in other fields, thereby obtaining greater progress with help of high technology. The study of carbon fiber reinforced epoxy composites in this paper has a positive effect on subsequent research.