Components Of Composite Materials Research Articles

An Experimental Study on the Performance of Materials for Repairing Cracks in Tunnel Linings under Erosive Environments

Addressing the current lining cracking problem in coastal tunnels, this paper independently introduces a novel type of repair material for tunnel lining cracks—the composite repair material consisting of waterborne epoxy resin and ultrafine cement (referred to as EC composite repair material). Through indoor testing, we have analyzed the change rule of the mass change rate, compressive strength, flexural strength, and chloride ion concentration of the repair material samples in erosive environments, with the dosage of each component in the EC composite repair material being varied. We have also investigated the working performance, mechanical properties, and microstructure of the repair material. The results of this study show that when the proportion of each component of ultrafine cement, waterborne epoxy resin, waterborne epoxy curing agent, waterborne polyurethane, defoamer, and water is 100:50:50:2.5:0.5:30, the performance of the EC composite repair material in a chloride ion-rich environment is optimal in all aspects. When the mixing ratio of each component of the EC composite repair material is as stated above, the repair material exhibits the best performance in a chloride ion erosion environment. With this ratio of components in the EC composite repair material, the fluidity, setting time, compressive strength, flexural strength, and bond strength of the repair material in a chloride ion erosion environment can meet the requirements of relevant specifications, and it is highly effective in repairing tunnel lining cracks. The polymeric film formed by the reaction between the waterborne epoxy resin emulsion and the curing agent fills the pores between the hydration products, resulting in a densely packed internal structure of EC composite repair material with enhanced erosion resistance, making it very suitable for repairing cracks in tunnel linings in erosive environments.

Laboratory Tests on the Possibility of Using Flax Fibers as a Plant-Origin Reinforcement Component in Composite Friction Materials for Vehicle Braking Systems.

Braking systems are extremely important in any vehicle. They convert the kinetic energy of motion into thermal energy that is dissipated into the atmosphere. Different vehicle groups have different nominal and maximum speeds and masses, so the amount of thermal energy that needs to be absorbed by the friction pads and then dissipated can vary significantly. Conventional friction materials are composite materials capable of withstanding high temperatures (in the order of 500-600 °C) and high mechanical loads resulting from braking intensity and vehicle weight. In small vehicles traveling at low speeds, where both the amount of thermal energy and its density are limited, the use of slightly weaker friction materials with better ecological properties can be considered. This work proposes a prototype composite friction material using flax fibers as reinforcement instead of the commonly used aramid. A number of samples were prepared and subjected to laboratory tests. The samples were prepared using components of plant origin, specifically flax fibers. This component acted as reinforcement in the composite friction material, replacing aramid commonly used for this purpose. The main tribological characteristics were determined, such as the values of the coefficients of friction and the coefficients of abrasive wear rate. For this purpose, an authorial method using ball-cratering contact was used. The results were analyzed using statistical methods. It was found that the composite material using flax fibers does not differ significantly in its tribological properties from conventional solutions; so, it can be assumed that it can be used in the vehicle's braking system.

A Visual Measurement Method for Deep Holes in Composite Material Aerospace Components.

The visual measurement of deep holes in composite material workpieces constitutes a critical step in the robotic assembly of aerospace components. The positioning accuracy of assembly holes significantly impacts the assembly quality of components. However, the complex texture of the composite material surface and mutual interference between the imaging of the inlet and outlet edges of deep holes significantly challenge hole detection. A visual measurement method for deep holes in composite materials based on the radial penalty Laplacian operator is proposed to address the issues by suppressing visual noise and enhancing the features of hole edges. Coupled with a novel inflection-point-removal algorithm, this approach enables the accurate detection of holes with a diameter of 10 mm and a depth of 50 mm in composite material components, achieving a measurement precision of 0.03 mm.

Cu1.3Mn1.7O4/LaNi0.6Fe0.4O3 composite with prospects for IT-SOFC/SOEC applications

Composite materials with the composition (100-x)Cu1.3Mn1.7O4/xLaNi0.6Fe0.4O3 (CMxLNF, where: x = 5, 10, 15, 20, 30, 40 and 50 wt%) were evaluated as possible coating materials for SOFC/SOEC metallic interconnects. The introduction of LaNi0.6Fe0.4O3 into spinel matrices improved electrical conductivity compared to pure Cu1.3Mn1.7O4. The measured Seebeck coefficient values indicate that carrier concentration increased with LaNi0.6Fe0.4O3 content, yet the activation energy of the carriers' mobility decreased. Extensive structural and microstructural studies of selected CM/LNF systems showed that composite material components exhibited high stability in relation to one another. Additionally, LaNi0.6Fe0.4O3 significantly improved the chemical stability of Cu1.3Mn1.7O4 in the presence of chromia, as tested after 150 h of exposure to air at 800 °C. Finally, coatings based on selected composite powders were deposited electrophoretically on the steel and were oxidized for 1500 h in air at 750 °C, confirming that CM10LNF can be applied as effective protective-conducting coatings on low-chromium ferritic steel.

Preparation and electromagnetic waves absorption performance of hibiscus-like CuS/SiC NWs@PANI in the GHz band

With the increasing demand for electromagnetic (EM) waves absorbing materials in communication, military, and electronic devices, the exploration of lightweight, wideband, and highly absorptive materials in the GHz frequency range has become urgent. This article presents a successful synthesis of hibiscus-like copper sulfide (CuS)/silicon carbide nanowires (SiC NWs) @polyaniline (PANI) composite material using a combination of hydrothermal and in-situ polymerization techniques. With a filling amount of only 25 wt% of CuS/SiC NWs@PANI in the paraffin transmissive matrix, the material exhibits a minimum reflection loss (RLmin) of −31.6 dB at a thickness of 2.1 mm, while providing an effective absorption bandwidth (EAB) of 4.5 GHz. As the filling amount increases to 35 wt%, the RLmin drastically reduces to −41.38 dB at a thickness of 2.3 mm. The CuS particles exhibit a unique multi-layered asymmetric hibiscus-like structure, which greatly enhances the reflection of EM waves. The conductive polymer PANI, forming a coating layer at the interface with CuS and SiC NWs, effectively enhances the conductive loss. The collaborative interactions among the components in the ternary composite material significantly boost the EM waves absorption performance. This article offers valuable insights into the preparation and real-world application of absorbent materials with distinctive microstructures, thus opening up new avenues for the design of composite absorbing materials.

Synthesis of nano- and ultra-fine refractory carbide powders by low-temperature calcium-carbothermic process and their grain growth during sintering

Metal carbides are widely used in various applications as catalysts, components of composite materials, cutting tools, and abrasive materials where the particle/grain size has a great impact on target properties. Here, we report a facile way to synthesize nano- and ultra-fine carbides of IVb-Vb groups, including high-entropy carbides, which are of interest nowadays due to their superior properties, by the combination of calcium-hydride reduction of metal oxides and the direct reaction of the reduced metals with carbon in one production step. By tailoring the synthesis parameters, it is possible to obtain the carbide powders of a size in the range of 50–1500 nm with high crystallinity. The average particle size is found to be dependent on the homologous synthesis temperature and follows a power law. We have also shown the possibility of obtaining ultrafine-grained bulk carbides (d = 0.24–0.9 μm) via spark-plasma sintering at a temperature of 1500–1650 °C with a relative density >95 % without using additives. The HEC (Ti,Zr,Nb,Hf,Ta)C has a higher activation energy of grain growth (collective recrystallization) compared to binary TaCx (x = 0.8 and 1), which confirms the effect of lattice distortion on diffusion coefficients. The suggested fabrication route can be widely used for nano and ultrafine carbide powder preparation on the industrial scale.

Synthesis and Physicochemical Properties of Functional Biphenyl Derivatives Designed for Anisotropic Nanomaterials

The synthesis and physicochemical properties of anisotropic functional biphenyl derivatives have been investigated. The biphenyl derivatives were obtained from commercially available 4',4-diphenyldicarboxylic acid, 4'-hydroxy-4-biphenylcarboxylic acid, 4'-hydroxy-4-cyanobiphenyl, 4'-pentyl-3'-chloro-4-hydroxybiphenyl using S-(–)-octan-2-ol, L-(–)-2-hydroxypropanoic (lactic) and 6-bromohexanoic acids. It was found that the synthesized compounds are able to interact specifically with nanoparticles and can be successfully used as effective components of anisotropic nanosized composite materials.

Synthesis and Study of the Properties of Corundum-Mullite Ceramic as a Component of Ceramic Composite Materials

Synthesis and Study of the Properties of Corundum-Mullite Ceramic as a Component of Ceramic Composite Materials

Mechanical and dynamic mechanical behavior of 3D printed waste slate particles filled acrylonitrile butadiene styrene composites

This study analyses the feasibility of utilizing waste slate particles as a strengthening component in affordable 3D-printed composite materials to address environmental issues associated with waste management. Composite filaments were created by incorporating waste slate particles (5 %, 10 %, and 15 % by weight) into an acrylonitrile butadiene styrene (ABS) matrix and subsequently evaluated for mechanical properties. A twin-screw extruder obtained the composite filaments, while test samples were produced using a 3D printer by fused deposition modelling. The developed composites have a gradual variation in evaluated properties, about an 8 % increment in hardness, and a 40 % increment in flexural and tensile modulus was noted on the inclusion of 15 wt% of waste slate particles in the ABS matrix. The composites filled with 10 wt% and 5 wt% waste slate particles exhibited the maximum flexural strength (65.24 MPa) and tensile strength (42.11 MPa), respectively. These values were 5 % and 8 % higher than those of unfilled ABS. Furthermore, it was shown that the ABS matrix saw a decrease in elongation and impact strength as the dosage of slate particles increased. The fractured surface morphology indicated that filament breaking, filler pullout, and the creation of voids between neighbouring layers were the primary causes of material failure. The dynamic mechanical analysis (DMA) results show the reinforcing effect of slate particles by an increase of storage modulus with 13 % at 35 °C for the composite with 10 wt% slate particles and 20 % for that with 15 wt% slate particles. DMA results analyzed the composite's adhesion factor, degree of entanglement, reinforcement efficiency factor, and effectiveness factor to clarify the reinforcing mechanism of slate particles. The study determines that the most effective utilization of waste slate particles in an ABS matrix is achieved by including 10 wt%. The results of this study enhance the concept of recycling waste slate powder and reveal the potential for their utilization in several industries, including the aerospace, automotive, healthcare, and architectural sectors of 3D printing.

Design and optimization of the dual-functional lattice-origami metamaterials

This study proposes a multi-scale composite lattice-origami metamaterial (MCLOM) to achieve excellent bandgap characteristics and energy absorption capacities. The MCLOMs are constructed by considering the high impedance mismatch of lattice structures, the spatial deformability of origami structures, and the tunability of the components in multi-scale composite materials. Firstly, elastic wave propagation characteristics are analyzed in the Bloch wave framework, revealing the realization of complete bandgaps and their generation mechanism by mode shape analysis and transmission spectrum. Subsequently, an optimization framework integrating the particle swarm optimization (PSO) algorithm is developed to maximize the first bandgap’s bandwidth by adjusting various component parameters. Under optimal distribution, the proposed metamaterials achieve remarkable improvements of 289% and 271% in the design objectives of two lattice-origami metamaterials with 90∘ dihedral angle compared to the initial distribution. It can be demonstrated that non-uniform distributions of multi-scale composite materials are dramatically effective for broadband wave attenuation. Additionally, while striving to widen the bandgap, the energy absorption capacities of structures are also crucial. The effect of the distribution of multi-scale composite materials with the optimal bandgap on the energy absorption performance is investigated. The results reveal that the optimal distribution of the lattice-origami metamaterials yields notable improvements of 48.26% and 34.86% under low-velocity impact, and 37.41% and 25.19% under medium-velocity impact. This work presents innovative concepts and approaches for devising and implementing novel dual-functional metamaterials, undoubtedly propelling the continual progress of material science and engineering technology in the times ahead.

Torsional Behavior of Concrete-Filled Circular Steel Tubes Strengthened with CFRP.

In order to study the torsional performance of steel tube concrete after reinforcement with a carbon-fiber-reinforced polymer (CFRP), the mechanical properties of 18 specimens were studied from both experimental and finite element perspectives. The T-θ curve and τ-γ curve of the specimen were measured in the experiment, and the failure mode of the specimen was analyzed. Subsequently, a reasonable finite element model was established using ABAQUS software, and the variation in various parameters surrounding the performance of the specimen was analyzed. Based on the experimental and finite element results, a formula for calculating the bearing capacity of the specimen was established. According to both the experimental and numerical results, the torsional bearing capacity of C-CF-CFRP-ST, defined as the torque endured by the specimen with maximum shear strain, was determined to be 15,000 με, together with its corresponding calculation formula. After the test, it was demonstrated that the main components of the concrete-filled CFRP-steel tube composite material-the steel tube and the concrete-could be used as reusable resources.

A Mesostructure Multivariant-Assembly Reinforced Ultratough Biomimicking Superglue.

The imitation of mussels and oysters to create high-performance adhesives is a cutting-edge field. The introduction of inorganic fillers is shown to significantly alter the adhesive's properties, yet the potential of mesoporous materials as fillers in adhesives is overlooked. In this study, the first report on the utilization of mesoporous materials in a biomimetic adhesive system is presented. Incorporating mesoporous silica nanoparticles (MSN) profoundly enhances the adhesion of pyrogallol (PG)-polyethylene imine (PEI) adhesive. As the MSN concentration increases, the adhesion strength to glass substrates undergoes an impressive fivefold improvement, reaching an outstanding 2.5 mPa. The adhesive forms an exceptionally strong bond, to the extent that the glass substrate fractures before joint failure. The comprehensive tests involving various polyphenols, polymers, and fillers reveal an intriguing phenomenon-the molecular structure of polyphenols significantly influences adhesive strength. Steric hindrance emerges as a crucial factor, regulating the balance between π-cation and charge interactions, which significantly impacts the multicomponent assembly of polyphenol-PEI-MSN and, consequently, adhesive strength. This groundbreaking research opens new avenues for the development of novel biomimetic materials.

Emerging Trends in Composite and Advanced Composite Materials Technology for Oil and Gas Industry

Composite and advanced composite materials are new age materials offering multiple benefits such as longer durability, lighter weight, high strength, tailor made properties etc. Lessons have been learnt from successful applications of composite and advanced composite materials and the results indicate that operators, designers and contractors are beginning to take a serious interest in their wide applications in Oil and Gas Industry. The most significant advances in the field of composite materials technology has been the use of glass-reinforced plastics (GRP) for pipelines and piping, structural applications for the top side secondary structures of offshore platforms and onshore installations. The introduction of carbon fibers has opened a new vista for composites applications in oil and gas industry particularly in deepwater operations such as drilling risers, production risers, umbilical, moorings etc. Numerous risers, mooring, pipeline, subsea and topside components made of polyester, titanium, glass/epoxy, and glass/carbon/epoxy materials are in the process of qualification for offshore use. These advanced composite material components have potential to extend capabilities of existing platform concept such as Semi submersibles, TLPs, FPSOs and SPARs. This paper presents the properties and advantages offered by composite and advanced composite materials, their current use and future potential applications in oil and gas industry.

Получение биокомпозитов с полимерной фазой пластифицированных ацетатов целлюлозы с различной степенью ацетилирования

It is anticipated that the creation of wood-polymer composites (WPC) made of naturally renewable polymers and their derivatives (biocomposites) would have a significant practical use due to the rise in prices for synthetic thermoplastic polymers derived from oil and gas. Furthermore, the necessity to replace synthetic polymers such as polyethylene, polypropylene, polyvinyl chloride, and others as components of composite materials is also associated with environmental hazards caused by their low degradation rate in the natural media (soil, water, and air). A further problem for manufacturers of WPC is the legislative requirement for autonomous neutralisation of production waste. One of the potential materials for practical application in the production of WPC are binders based on plasticised cellulose acetates. Russian and foreign scientists have studied the influence of the degree of acetylation of cellulose acetate on the properties of polymeric materials that do not contain lignocellulose fillers. There is no information found concerning the secondary use of cellulose acetate waste for the production of WPC. This article presents the results of an investigation into the hot pressing of biocomposites with a polymer phase of plasticised cellulose acetates of varying degrees of acetylation and fillers: wood flour and waste acetate photographic film. An experimental and statistical dependence of the effect of the degree of acetylation of cellulose acetate and filler content in the biocomposite on its properties was developed, sufficient to exceed a confidence level of 0.9. The experimental specifications included decomposition in activated soil, water absorption, bending strength, Brinell hardness, etc. Some test results showed that the derived biocomposites have the same level of properties as the reference WPC, which consists of a high-density polyethylene phase with a wood flour content of 50 %. The derived dependencies allow us to predict changes in the properties of biocomposites at different degrees of acetylation of plasticised cellulose acetate and filler content. Moreover, they solve the problem of choosing the optimal chemical combination for WPC for manufacturing a specific product by hot pressing. For citation: Shkuro A.E., Glukhikh V.V., Usova K.A., Chirkov D.D., Zakharov P.S., Vurasko A.V. Deriving Biocomposites of Polymer Phase Plasticised Cellulose Acetates with Varying Degrees of Acetylation. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 4, pp. 155–168. (In Russ.). https://doi.org/10.37482/0536-1036-2023-4-155-168

Investigation on mechanical properties of novel natural fiber-epoxy resin hybrid composites for engineering structural applications

Polymers and fibers are the main components of cementitious composite materials to reinforce concrete. The synthetic fibers used in concrete composites typically weigh and also, and they are easily subjected to thermal degradation. To tackle the above issues, researchers developed various natural fiber-based composites. In the paper, the mechanical characteristics of hybrid composites were examined. The hybrid composites were developed using Madar, Gongura, and Hibiscus cannabinus fibers. The polyester resin was the matrix. The fibers were treated chemically using a 5% sodium hydroxide (NaOH) solution. The fibers were then carefully cleaned with distilled water twice and baked for 70 min at 60 °C. For the evaluation of the tensile, flexural, and impact properties of the hybrid composites, specimens were made in accordance with ASTM standards. The treated composite sample (S3) specimen exhibits a tensile strength (TS) of approximately 34.720 N/mm2, flexural strength (FS) of 77.957 MPa, and flexural modulus (FM) of 1548.588 GPa. The average water absorption of the sample is only 2.45%. The hardness and impact strength (IS) of the samples are also superior to those of several other composites studied in the literature. Hence, the proposed hybrid composites could be a potential material for reinforcing the concrete composites to provide a higher service rate and greater durability to the structures.

Flax and hemp composites: Mechanical characterization and numerical modeling

Nowadays, in the global composites industry, an increasing number of companies are studying high-quality innovative and green solutions, in order to achieve the environmental sustainability goals. In this context, the use of a natural fiber reinforced polymer in the design of structural components needs to be validated through experimental mechanical tests. This study provides an overview of the behaviors of flax/epoxy and hemp/epoxy laminates subjected to tensile, four-point bending, and Low-Velocity Impact (LVI) tests, both from an experimental and numerical point of view. For each type of test, finite element models were simulated using the explicit code LS-DYNA in order to characterize the materials, reproduce the load-displacement plots, and analyze the damage evolution of the laminates. Two different types of mesh modeling were investigated for the models: shell and solid elements. In both cases, a proper contact modeling between layers was carried out to account for delamination phenomena of the material. The results obtained show an agreement between the experimental response and the simulated one, highlighting the possibility of designing and manufacturing structural components in composite material reinforced with natural fibers.

Study on the thermal transformation of basic components of wind turbine blade

AbstractTo alleviate the environmental pollution caused by waste wind turbine blades and provide new ideas for recycling, the thermochemical characteristics of four basic components of composite materials commonly used in wind turbine blades were studied in this paper. Thermogravimetric experiments in different atmospheres and heating rates, and thermogravimetric‐infrared combined experiments were carried out. The results show that the reaction of epoxy resin and thermoplastic polyurethane was easy and deep in N2 and CO2. Except for glass fiber, the other three components showed different combustion characteristics in air. The maximum reaction rates and activation energy of resin‐based components in N2 increased with increasing heating rate. The pyrolysis products of the four basic components all contained CO2 and CO, and some aromatic substances could be generated during the thermal transformation of epoxy resin and thermoplastic polyurethane. It can be concluded that the thermal transformation properties of the basic components of the composite material of wind turbine blades can be used to treat the waste blades, making the resin as the matrix material undergo a thermal transformation reaction and recover the fiber. This is to effectively guarantee the green and sustainable development of wind power generation.

Enhancement of Bi-based niobate pyrochlores conductivity with Ru-doping. Structural, optical, and electrical properties

New Ru-doped bismuth-based pyrochlores were synthesized. The effects of Ru-doping in Bi1.5Mg0.375Cu0.375Nb1.5-xRuxO7-δ on the formation of the crystal structure, stability, optical, and electrical properties of the compositions were studied. For compositions up to x = 0.1, only a phase of the pyrochlore type was detected by X-ray diffraction method (XRD) and energy dispersive X-ray analysis (EDX). Small impurities of Bi2Ru2O7, RuO2 and CuO were found for samples with x ≥ 0.25. The lattice parameters of pyrochlores decrease upon doping with Ru. X-ray diffraction modeling revealed the structural stability of the doped compositions and the distribution of Ru4+ cations in the B sites of the A2B2O6O' pyrochlore structure. A decrease in the band gap energy Eg was observed upon doping with Ru: 2.40 (x = 0) – 2.10 eV (x = 0.5) for the direct transition and 1.52 (x = 0) – 0.16 eV (x = 0.5) for indirect transition as a result of optical spectra analysis and DFT-HSE03 calculation. The chemical compatibility of the obtained pyrochlores with the manganite perovskite La0.7Sr0.3MnO3 was studied. The pyrochlores can be considered as a component of cathode composite material for using in intermediate temperature solid oxide fuel cells (IT-SOFC).

Soft interphase volume fraction of composites containing arbitrarily shaped mono−/poly-disperse fillers: Theoretical and numerical investigations

Interphase, a crucial structural component in composite materials connecting the fillers and matrix, typically possesses unique physical properties and plays a crucial role in determining the overall transport and mechanical behaviors of the material system. In this work, we propose a generic theoretical framework to precisely determine the volume fraction fsi of soft interphase around arbitrarily shaped hard fillers, including both convex and concave shapes with arbitrary size dispersity, in three−/two-dimensional (3D/2D) heterogeneous material systems. Specifically, a composite material is regarded as a three-phase structure composed of a homogeneous matrix, hard anisotropic fillers, and their surrounding interpenetrable interphase layers with a constant “thickness” for each filler volume fraction. The seminal hard -core soft-shell (i.e., cherry-pit) model and statistical geometry theories are employed to derive explicit analytical formalism of fsi which is subsequently verified via a series of numerical experiments using Monte Carlo sampling. We systematically investigate the dependence of fsi on the filler characteristics, including filler volume fraction, geometric size factor, fineness, and filler shape and size distributions. Interestingly, we find that filler sphericity can be used as the sole shape descriptor to control the interphase volume fraction for all filler shapes, including those with irregular non-convex morphologies. Our framework provides an efficient and accurate tool for composite design that complements expansive numerical simulations, which is also readily applicable to understanding the effect of fsi on physical properties of composites.

A systematic study on material properties of water retted Sterculia and Bauhinia fiber

Lignocellulose biomass forms an important component of traditional and next generation composite materials. To obtain desired properties, the biomass needs to be chemo‒mechanically processed at different levels. The raw lignocellulose fiber obtained from Sterculia villosa (Roxb.) and Bauhinia vahlii is traditionally believed to have high water stability; and therefore used in rural areas of South Asian regions to secure objects submerged under water. In this research, we systematically studied several material properties of raw Sterculia and Bauhinia fiber samples retted for 0, 20, 30 and 55 days (n=8). Water retting resulted in significant decrease in lignin and extractives content (p<0.05) and increase in cellulose content. Fiber bundle strength of Sterculia fiber increased with retting time (R2= 0.7) but Bauhinia fiber did not show significant change (p>0.05). Interestingly, water retting resulted in increased thermal stability in both fiber types. These findings suggested that the fiber studied have excellent water stability. The observed trend in mechanical and thermal properties could have resulted from crystallinity change and/or nominal fiber damage as supported by XRD and SEM imaging data; respectively. These findings suggested that Sterculia and Bauhinia fiber biomass could be an important component of biodegradable composite materials which are intended for high wetting and/or humid conditions.