Mechanical Properties Of Carbon Fibers Research Articles

Mechanical and Tribological Properties of Carbon Fiber Reinforced POM Composite Filled With Maleamidic Acid Treated Carbon Nanotube

ABSTRACTIn order to attain improved mechanical properties of the carbon fiber (CF) reinforced polyoxymethylene (POM) composite, maleamidic acid treated carbon nanotube (CNT) was deposited on carbon fiber. The mechanical properties of composites have been investigated. The tensile strength values of the treated CF/POM composites at all CNT mixing ratios are found to be higher than that of untreated one. The surface morphologies of the fractured surfaces of the composites were recorded using scanning electron microscopy (SEM) to gain information about the fiber–matrix interfacial adhesion in the composites. The friction coefficient of all the CF/POM/CNT composites decrease as the load increases from 10 to 20 N under the same sliding speed of 1000 r/min. XPS results showed that the formation of C–O, C=O, and O–C=O based species give rise to chemical bonds of the CF and the POM.

High-throughput in-situ mechanical evaluation and parameter optimization for 3D printing of continuous carbon fiber composites

The mechanical properties of carbon fiber reinforced thermoplastic (CFRTP) molded parts produced by thermal fusion lamination 3D printing vary with printing conditions. This study assesses the influence of the 3D printing parameters on the mechanical properties of resulting CFRTP products through parameter evaluation testing. An in-situ three-point bending test mechanism was developed to enhance the efficiency of these tests, allowing the same 3D printer to handle all processes from printing multiple CFRTP specimens simultaneously to conducting a bending test, reducing manual handling time to about one minute. Using this modified 3D printer, 700 specimens with varying printing conditions were produced, and their flexural strength was measured semi-automatically. Results revealed that the flexural strength of the 3D-printed CFRTP object varied with nozzle temperature, printing pitch, and stacking pitch, but not with printing speed. Machine learning was then employed to predict the maximum flexural strength and determine optimal printing parameters using the collected data as training data.

Effects of argon plasma treatment on carbon fiber surface characteric and its reinforcing polyimide composites interfacial properties at room and elevated temperatures

In high temperature conditions, this can cause considerable changes in the mechanical properties of the composite. In order to determine the structural and mechanical property changes that occur in composite materials at elevated temperatures, to elucidate the damage mechanisms at elevated temperatures, and to improve the stability and durability of the materials. This paper studies how plasma treatment time affects the surface polarity, roughness, wettability and mechanical properties of carbon fibers. The results showed that the best wettability was attained after 10 min of plasma treatment, and new oxygen-containing functional groups (COO- and -C=O) developed on the fiber surface. The fundamental explanation is that during plasma surface treatment, the CH group in the bisphenol A part chain segment present in the epoxy resin sizing agent's composition is oxidized, forming an organic oxide layer. In this paper, the plasma modification technology was utilized to improve the interfacial compatibility of carbon fiber and Polyimide (PI) resin, and the interlaminar shear strength reached 103.98 MPa, up 10.49 %, and the strength retention rate was 84.3 % at 300 °C. In this paper, the plasma modification technique was employed to increase the interfacial compatibility of carbon fiber and PI resin. It was found that the Inductively Coupled Plasma (ICP) treated carbon fiber surfaces underwent physical and chemical changes that effectively enhanced the interfacial compatibility with the resin. However, the chemical groups and physically etched regions on the surface of the plasma-modified fibers are able to impede the relative motion of the resin to a certain extent, thus improving the interfacial strength.

Artificial intelligence and machine learning for additive manufacturing composites toward enriching Metaverse technology

<p class="Abstract">As a result of the growing significance and application of technology across a wide range of fields, digital environments such as Metaverse started to take shape over the span of the previous decade. This study aims to discover an area of engineering that could benefit from this new technology by developing an artificial intelligence (AI)—based approach to analyzing and predicting the mechanical properties of carbon fiber reinforced syntactic thermoset composites that are made through additive manufacturing (AM). These composites are intended to be utilized as a tool for metaverse technology in a variety of domains—as the presence of the limitations in the currently experimental methods. The metaverse allows for the generation of simulations through the application of artificial intelligence (AI) and machine learning (ML). Consequently, this paves the way for individuals to investigate various design possibilities and view the virtual manifestation of those possibilities. This is made possible by the use of machine learning algorithms, which allow for the monitoring and evaluation of user performance, as well as the provision of individualized feedback and suggestions for improvement. As a consequence of this, it is feasible that professionals will be able to get education and training that are both more efficient and effective. Consequently, this work aims to introduce an Adaptive Neuro-Fuzzy Inference System (ANFIS)—based model, which is able to effectively anticipate the behavior of mechanical systems in a variety of settings without the need for significant measurements. The validity of the ANFIS model was determined through the utilization of flexure and compression testing. The approach that was used to improve the technical assessment of the manufactured composites—is verified by the model’s near-realistic predictions. Moreover, this method is superb for lowering weight, enhancing mechanical qualities, and minimizing product complexity.</p>

Enhancing interfacial locking of the CF and PBPESK resin by in-situ electrochemical deposition of MOF nanoparticles

The interfacial bonding of carbon fiber reinforced polymer composites plays a critical role in the overall performance of the composites. Poor interfacial bonding leads to catastrophic damage of composites when subjected to external loads. In this study, three-dimensional (3D) NH2-UiO-66 nanoparticles in-situ synthesis on the carbon fiber (CF) surface using an electrochemical method was achieved facilely and efficiently to enhance the interfacial adhesion of CF/PBPESK composites. The influence of incorporating 3D NH2-UiO-66 nanoparticles into the interphase on the interfacial and mechanical properties of carbon fiber reinforced composites was systematically investigated. The NH2-UiO-66 nanoparticles significantly increased the carbon fibers surface energy. The flexural, interlaminar shear and interfacial shear strength of the N–CF–6min/PBPESK composite were improved by 19 %, 31 %, and 93 %, respectively, compared to the D-CF/PBPESK composite. Furthermore, the interfacial failure mechanism of the composites was investigated. This approach offered a simple and efficient strategy for the in-situ synthesis of interfacial phase characterized by robust mechanical locking effects.

Effect of tungsten carbide interface decoration on thermal and mechanical properties of carbon fiber reinforced copper matrix composites

The use of carbon fiber (CF)/copper (Cu) composites as thermal management materials shows significant promise. However, inadequate interface bonding hinders their thermal properties. This study introduces a novel method to create tungsten carbide–coated CFs (CF(WC)) using the molten salt method. These coated fibers are then used to develop a CF(WC)/Cu composite through vacuum hot-pressing sintering. Results reveal that the WC coating, formed at 1100 ℃ for 60min with a tungsten trioxide/CF molar ratio of 1/10, is continuous, crack-free, and has an appropriate thickness. The WC coating facilitates excellent interface bonding between Cu and CF, thus effectively improving the initial poor interface bonding. With similar 50% fiber content, the CF(WC)/Cu composite exhibits better thermal and mechanical properties than the CF/Cu composite. The in-plane direction thermal conductivity and bending strength of the CF(WC)/Cu composite are 398.7 ± 8.1Wm−1 K−1 and 195.3 ± 6.2MPa, which are 35.3% and 90.4% higher, respectively, than those of the CF/Cu composite. Additionally, the in-plane direction coefficient of thermal expansion is 6.5 ± 0.3 × 10−6 K−1, representing a notable reduction of 37.5%. These exceptional properties, coupled with the simplicity and efficacy of the preparation process, offer valuable insights for the advancement of carbon/Cu thermal management materials.

Synchronously Repairing Core/Surface Defects of Carbon Fibers by In Situ Growth of ZIF-8 and Uniquely Matched High-Energy Irradiation.

Currently, the actual mechanical properties of carbon fibers (CF) differ significantly from the theoretical values. This is primarily attributed to significant limitations imposed by structural defects, greatly hindering the widespread application of CF. To solve this problem, we used in situ growth of zeolitic imidazolate framework-8 (ZIF-8) and γ rays to modulate the core-shell of CF in this study. For the surface structure of CF during the process of γ irradiation, the organic structure within ZIF-8 gradually degrades and forms a cross-linking structure with the surface defects of the CF. This process significantly enhances the binding strength between inorganic material from the postdecomposition of ZIF-8 and the carbon layer on the surface of CF, repairing the surface defects. For the internal structure of CF, γ irradiation can improve the orientation of the internal micropores of CF and increase the degree of internal graphitization of CF. In this paper, an in-depth analysis of CF before and after repair was conducted by using characterization techniques such as nanoindentation and ultrasmall angle X-ray scattering (USAXS). Compared to unmodified CF, its mechanical properties improved by approximately 19.99%, which exceeds that in approximately 95% of similar works in the field.

CFRTP single-lap adhesive bonding and its mechanical performance enhanced by laser surface treatment: Finite element simulation and experimental validation

The outstanding mechanical properties of carbon fiber reinforced thermoplastic polymer (CFRTP) have led to its widespread application in many industrial sectors. In response to the engineering challenge of repairing large non-critical CFRTP structural components in situ, an infrared fiber laser surface cleaning technology is proposed to treat the bonding interface and enhance the tensile strength of polypropylene (PP)-based CFRTP single-lap bonded joints. Specifically, through single-factor and orthogonal experiments, the impact of different process parameters on the properties of the bonded joints was identified first. Then, online temperature monitoring was performed to elucidate the laser treatment mechanism of the CFRTP sample interface. Surface morphology of the laser-treated samples further indicates that when the temperature of the sample surface surpasses the resin decomposition temperature with extended holding time, the resin could be removed from the surface more thoroughly. Additionally, a novel three-dimensional woven finite element (FE) model, accounting for anisotropic heat transfer, was established to predict the surface temperature and cleaning quality of CFRTP. The FE model incorporates the anisotropic heat transfer characteristics of carbon fibers, thus accurately simulating the heat transfer behaviors between carbon fibers and the resin matrix. The laser ablation mechanism is elucidated by examining the surface ablation morphologies and peak surface temperatures. A comparison between experimental results and FE simulations demonstrated a notable coherence in the trend of surface morphology variations, with discrepancies in peak surface temperatures ranging from 3.29 % to 24.63 %. The experimental tests proved that the shear strength of single-lap bonded joints reaches its maximum value when the laser power is 35 W, the scanning speed is 2500 mm/s, and the number of scans is four. The enhancement of the mechanical properties of bonded joints can be attributed to the improved wettability and higher surface free energy of the laser-treated samples.

Comprehensive evaluation of interfacial interactions optimization for CF reinforced high-performance thermoplastic composites by electrochemical deposition of conjugated polymers

The mechanical properties of carbon fiber (CF) reinforced high-performance thermoplastic composites are significantly compromised due to inadequate interface bonding between CF and matrix. In this study, electrochemical polymerization techniques were employed to modify CFs with polypyrrole (PPy), poly-aniline (PANI), and poly-o-phenylenediamine (PoPd), to systematically investigate the impact of conjugated polymers on the interfacial properties of CF/copoly (phthalazinone ether sulfone ketone)s (PPESK) composites through a combination of experimental and molecular dynamics (MD) approaches. The findings revealed distinct differences among these conjugated polymers in terms of their effects on both IFSS and ILSS for CF/PPESK composites. Among all tested laminates, PoPd@CF-60s/PPESK exhibited the highest IFSS, ILSS and flexural strength values of 39.8 MPa, 75.6 MPa, and 1494 MPa, respectively, 94.1 %, 20.6 %, and 47.6 % higher than those of CF-desized/PPESK, without compromising CFs strength and thermal resistance of CF/PPESK composites. MD simulations combined with fracture morphology analysis confirmed that compatibility between conjugated polymers and matrix played a pivotal role in enhancing interface properties for CF/PPESK composites. Furthermore, the AFM outcomes demonstrated that the PoPd layer could serve as the modulus transition layer between the CF phase and the PPESK phase, which effectively enhancing the load transfer efficiency between the two phases under external forces. To summarize, this work presents a straightforward yet non-destructive approach that effectively enhances the interface strength within advanced CF reinforced high performance thermoplastic polymer composites (CFRHPTPs).

Effect of fiber surface treatment with silane coupling agents and carbon nanotubes on mechanical properties of carbon fiber reinforced polyamide 6 composites

Effect of fiber surface treatment with silane coupling agents and carbon nanotubes on mechanical properties of carbon fiber reinforced polyamide 6 composites

Enhanced mechanical property, high-temperature oxidation and ablation resistance of carbon fiber/phenolic composites reinforced by attapulgite

To meet the thermal protection and load-bearing requirements of ultra-high-speed vehicles, it is urgent to improve the ablation resistance, high-temperature oxidation resistance and mechanical properties of carbon fiber/ boron phenolic resin (CF/BPR) composites simultaneously. Herein, polyhedral oligomeric silsesquioxane-modified attapulgite (ASP) with abundant porous structure was successfully introduced into the CF/BPR (CF/ASPBPR). The co-effect of ceramization, high infrared emissivity, and low thermal conductivity endowed the CF/ASPBPR with desirable ablation resistance, where the linear ablation rate and mass ablation rate reduced to 0.038 mm/s and 0.035 g/s, respectively. Meanwhile, due to the high thermal stability and energy dissipation of ASP, the CF/ASPBPR also presented the interlaminar shear strength of 35.40 and 9.79 MPa before and after high-temperature treatment, which were 24 % and 63 % higher than that of CF/BPR, respectively. This study provides a promising pathway for preparing advanced thermal protection materials that can adapt to severe mechanical spalling and thermochemical erosion environments.

Increasing softening point of isotropic spinnable asphalt by two-step preparation from ethylene tar residue modified with bio tar residue

Carbon fiber prepared from asphalt may be a critical type of low-weight chemical material of excellent mechanical performances. Here, an isotropic spinnable asphalt (EBA) was prepared from ethylene tar residue (ETR) by a two-step method of bio tar residue (BTR) through co-polymerization-air blowing, and isotropic asphalt carbon fibers were prepared from the product asphalt. The main types of molecules contained in the two feedstocks were determined by 1H NMR and LDI-TOF MS analyses. The co-polymerization behavior and thermal stability of the asphalt blends were analyzed using polarized light microscopy and thermogravimetric analyzer, respectively. Finally, the morphology and mechanical properties of carbon fibers made from EBA were evaluated by scanning electron microscope and universal testing machine. The results show that BTR contains much more oxygen-containing functional groups and unique long-chain sawtooth molecular structure; the former can promote the reactivity of the co-polymerization reaction, and the latter can limit the formation of large-plane cyclic aromatic hydrocarbon polymers due to the spatial resistance effect to greatly reduce the content of the mesophase. The softening point of the product asphalt shows a tendency of increasing and then decreasing with the increase of the proportion of BTR in the raw material mixture, and a reaction mechanism based on linear and bulky molecules is proposed to explain it by analogy with the structure of macromolecules. Consequently, the EBA made from a mixture of ETR and BTR at ideal moderate proportions has excellent performance in terms of softening point and mesophase content than ETRO made from ETR alone, and the carbon fiber made has a high tensile strength of 1.82 GPa with an elastic modulus of 38.9 GPa, which has reached the level of high tensile strength carbon fiber. Therefore, the use of inexpensive renewable energy bio-asphalt in the modification of heavy oil to obtain high softening point isotropic asphalt for preparing isotropic carbon fiber with excellent properties is achievable.

Development of a novel characterization model for innovative bionic helical carbon fiber tows

The design of bionic helical structures significantly enhances load-bearing capacity and impact resistance, demonstrating great potential for mechanical property improvement. However, there is still a lack of precise characterization models for the helical structures of carbon fibers, which constrains their potential in engineering applications. This paper successfully fabricated helical carbon fiber tows using a carbon fiber twisting technique and introduced a novel intersecting circular cross-section model to thoroughly investigate the influence of the helical structure on the mechanical properties of carbon fiber tows. Tensile test results show that at a twist angle of 5°, the helical structure increases the tensile strength and fracture toughness of carbon fiber tows by 13.6% and 34.3%, respectively. Additionally, the introduction of complex structures such as helices significantly influences the material’s modulus, and precise modulus prediction is crucial for material optimization and practical application. Based on the newly proposed model, a modulus prediction model is developed, demonstrating higher predictive accuracy than traditional models with a prediction error of 2.8%. Finite element simulations further validate the practicality and superiority of the intersecting circular cross-section model. Compared to traditional models, the predictions of the novel model are closer to experimental data, with a prediction error below 2%, emphasizing the significant impact of microstructures on macroscopic properties and offering a new perspective for modeling complex material systems. These findings provide crucial theoretical and methodological support for the design and performance optimization of carbon fiber materials.

Simulation analysis of cryogenic mechanical properties of carbon fiber reinforced silicon-containing epoxy resin composite

The use of carbon fiber-reinforced resin matrix composites instead of metals to manufacture cryogenic propellant tanks for spacecrafts is a development trend in the world aerospace industry. Cryogenic mechanical properties of the composites should be investigated in detail due to that the ultra-low temperature environment may cause micro cracks in the composites, leading to propellant leakage. In the present study, cryogenic tensile properties of a carbon fiber reinforced silicon-containing epoxy resin aomposite are investigated using experimental and numerical simulation methods. A silicon-containing epoxy resin with excellent cryogenic mechanical properties is developed by introducing a synthesized organic silicon polymer epoxidized polysiloxane and Nano-SiO2 into bisphenol F type epoxy resin. The tensile strength and modulus of the silicon-containing epoxy resin at −180 °C are 202.63 MPa and 7.81 GPa, which are 16.71% and 3.03% higher than those of bisphenol F type epoxy resin. The tensile strength of the silicon-containing epoxy resin at −180 °C is increased by 107.7% compared to that at room temperature, and the modulus at −180 °C is nearly twice that at room temperature. The carbon fiber reinforced silicon-containing epoxy resin composite is prepared by vacuum injection molding. The finite element model for the representative volume element of the composite unidirectional plate is established. The random sequence expansion method is used to randomly distribute the carbon fibers and simulate the thermal residual stress, the elastic performance, and the damage of the composite at cryogenic environments. Through comparison, it is found that the simulation results are in good agreement with the experimental results. The simulation reliability for cryogenic mechanical properties of carbon fiber reinforced resin matrix composites is verified. It is expected to provide a reference for the analysis and evaluation of cryogenic mechanical properties of composite tanks.

Mechanical Properties of Carbon Fiber Reinforced Materials for 3D Printing of Ankle Foot Orthoses

Mechanical Properties of Carbon Fiber Reinforced Materials for 3D Printing of Ankle Foot Orthoses

Optimized mechanical properties of carbon fiber reinforced thermoplastics by tuning polymer chain length based on quad‐screw extrusion

Optimized mechanical properties of carbon fiber reinforced thermoplastics by tuning polymer chain length based on quad‐screw extrusion

Boosting mechanical properties of carbon fibers by gas-liquid dual-effect approach

The tensile strength and tensile modulus of existing carbon fibers (CFs) are 3 %–5 % of the theoretical values, which greatly limits the performance of CFs when used alone or as a reinforcing material. To increase the chemical reaction activity and roughness of the surface of CFs based on the enhancement of their mechanical properties, a comprehensive treatment of CFs was carried out by the gas-liquid dual-effect method. CFs were oxidized at high temperatures after immersion treatment using cobalt nitrate solution, and the effects of cobalt nitrate solution concentration, oxidation time, and calcination temperature on the surface morphology, functional groups, structural defects, and mechanical properties of CFs were investigated by the controlled-variable method. The results showed that when the concentration of cobalt nitrate solution was 0.2 molL-1, the calcination temperature was 200 °C, and the oxidation time was 4 h, the modification effect was the best. At this time, the tensile strength of CF is 6104.50 MPa, which is 40.35 % higher than that of the pure CF, and the tensile modulus is 378.56 GPa, which is 13.27 % higher than that of the pure CF, with a significant enhancement effect. It can offer feasible ideas for further research and development of CF composites, and provide an effective way to promote the industrialization of modified CFs for application.

Tensile properties of helical carbon fiber tows

The carbon fiber used in the load-bearing structural components often exhibits a relatively low toughness and a limited elongation at the point of failure within its carbon fiber tows. To address this challenge, we introduced a bionic helical structure as an innovative alternative to the conventional straight carbon fiber tows, resulting in a novel material characterized by enhanced strength and toughness. Pioneering a theoretical model, we delved into the effects of the helical angle on the tensile mechanical properties of helical carbon fiber tows for the first time. Subsequently, we conducted experimental trials to validate our theoretical findings and identified an optimal range for the helical angle. The optimized helical angle enhances additional lateral interactions, improving the bonding between the fibers and the resin. The characteristics of the helical structure increase the overall fracture elongation of the fiber tows. Tensile tests revealed a remarkable 10.8 % increase in maximum tensile strength and a significant 46 % enhancement in toughness when the tows were fully impregnated with epoxy resin using this optimal helical angle. Incorporating the helical structures at this optimized angle represents a breakthrough in improving the mechanical properties of carbon fiber tows, offering a unique solution to strike a balance between strength and toughness in carbon fiber composites.

Synergistic effect of spinning drawing and preoxidation stretching on the orientation structure of mesophase pitch carbon fibers

Mesophase pitch carbon fiber has shown remarkable prospects in specialty carbon material. The mechanical properties of mesophase pitch carbon fiber (CF) cannot be precisely controlled because of the difficulty of forming process regulation. The early forming of carbon fiber (precursor fiber (PF) and pre-oxidation fiber (OF)) is difficult to regulate, such as carbon microcrystal and carbon layer texture, while cause the irreversible growth of carbonization process. Herein, a synergy strategy of spinning drawing and preoxidation stretching is developed to optimize orientation structure, eliminate morphology defects and improve mechanical properties. A synergistic effect of superior spinning drawing and suitable preoxidation stretching is beneficial to adjust the more order rearrangement of carbon microcrystals. The tensile strength of carbon fibers with spinning drawing and preoxidation stretching is increased by 1.7 times, and their defects are reduced by 40%. The results show that the excellent mechanical property of carbon fiber is contributed by the extrusion stress caused by high oxidation crosslinked surface layer under tension, and the micro-flow and rearrangement of carbon microcrystals induced by extrusion stress. A mechanical strengthening mechanism of carbon fiber is proposed, which provides guidance for high-performance mesophase pitch carbon fiber.

Comparison of dynamic mechanical properties of carbon fiber and graphene oxide grafted carbon fiber modified concrete

Graphene oxide grafted carbon fiber (CF-GO) is successfully prepared by the chemical grafting method of “grafting to”. The physical properties, mechanical properties and dispersion effects of carbon fiber and graphene oxide are comparatively studied. Carbon fiber modified concrete (CFMC) and graphene oxide grafted carbon fiber modified concrete (CF-GOMC) are prepared, and the dynamic mechanical properties and fiber/concrete matrix interfaces of CFMC and CF-GOMC are comparatively studied. The results show that the physical and mechanical properties of CF-GO are improved compared with carbon fiber, and the dispersion effect of CF-GO in concrete matrix is better than that of carbon fiber. When the fiber content is the same, the dynamic mechanical properties of CF-GOMC are better than that of CFMC, and the strain rate effect of dynamic mechanical properties indicatoes is stronger than that of CFMC. The strengthening and toughening effect of CF-GO on concrete is better than that of carbon fiber. The carbon fiber/concrete matrix interface exhibits a relatively large porosity, while the CF-GO/concrete matrix interface is well bonded. The graphene oxide on the surface of CF-GO exerts an “expansion bolt” effect, attracting the deposition of hydration product crystals and regulating their crystal structure.