3D printing has emerged as an advanced manufacturing technique for carbon fiber reinforced composites and relevant structures that endure significant dynamic loads in engineering applications.The dynamic behavior of t...3D printing has emerged as an advanced manufacturing technique for carbon fiber reinforced composites and relevant structures that endure significant dynamic loads in engineering applications.The dynamic behavior of these materials,primarily influenced by the dynamic fiber pullout interface strength necessitates investigation into the rate-dependent fiber/matrix interfacial strength.This study modifies a Hopkinson tension bar to conduct dynamic pullout tests on a single fiber bundle,utilizing a low-impedance bar and an in-situ calibrated semiconductor strain gauge to capture weak stress signals.Stress equilibrium analyses are performed to validate the transient dynamic loading on single fiber bundle specimens.The results reveal that the fiber/matrix interfacial strength is rate-dependent,increasing with the loading rate,while remaining unaffected by the embedded length.Fracture microstructural analyses show minimal fiber pullout due to high interfacial stresses induced by longer embedded lengths.Lastly,suggestions are made for the efficient design of fiber pullout experiments.展开更多
Piezoelectric materials are capable of actuation and sensing and have been used in a wide variety of smart devices and structures.Active fiber composite and macro fiber composite are newly developed types of piezoelec...Piezoelectric materials are capable of actuation and sensing and have been used in a wide variety of smart devices and structures.Active fiber composite and macro fiber composite are newly developed types of piezoelectric composites,and show superior properties to monolithic piezoelectric wafer due to their distinctive structures.Numerous work has focused on the performance prediction of the composites by evaluation of structural parameters and properties of the constituent materials with analytical and numerical methods.Various applications have been explored for the piezoelectric fiber composites,including vibration and noise control,health monitoring,morphing of structures and energy harvesting,in which the composites play key role and demonstrate the necessity for further development.展开更多
The morphological structure of various epoxies toughened with a special amorphous thermoplastic PEK-C and their carbon fiber composites were studied by using SEM. For both cases, phase separation and inversion took pl...The morphological structure of various epoxies toughened with a special amorphous thermoplastic PEK-C and their carbon fiber composites were studied by using SEM. For both cases, phase separation and inversion took place to form fine epoxy-rich globules dispersing in the PEK-C matrix, in which the epoxy-rich phase had the absolutely higher volume fraction. The phase structure and the interfacial properties were also studied by means of FTIR, DSC, and DMTA as well. An accompanying mechanical determination revealed that an improved toughness was achieved both in the blend casts and in the carbon fiber composites. A composite structural model was hence suggested.展开更多
The emerging biomass-based epoxy vitrimers hold great potential to fulfill the requirements for sustainable development of society.Since the existence of dynamic chemical bonds in vitrimers often reduces both the ther...The emerging biomass-based epoxy vitrimers hold great potential to fulfill the requirements for sustainable development of society.Since the existence of dynamic chemical bonds in vitrimers often reduces both the thermal and mechanical properties of epoxy resins, it is challenging to produce recyclable epoxy vitrimers with both excellent mechanical properties and good thermal stability. Herein, a monomer 4-(((5-(hydroxymethyl)furan-2-yl)methylene)amino)phenol(FCN) containing furan ring with potential to form high density of hydrogen bonding among repeating units is designed and copolymerized with glycerol triglycidyl ether to yield epoxy resin(FCN-GTE), which intrinsically has dual hydrogen bond networks, dynamic imine structure and resultant high performance. Importantly, as compared to the BPA-GTE, the FCN-GTE exhibits significantly improved mechanical properties owing to the increased density of hydrogen bond network and physical crosslinking interaction. Furthermore, density functional theory(DFT) calculation and in situ FTIR analysis is conducted to decipher the formation mechanism of hydrogen bond network. In addition, the FCN-GTE possesses superior UV shielding, chemical degradation, and recyclability because of the existence of abundant imine bonds. Notably, the FCN-GTE-based carbon fiber composites could be completely recycled in an amine solution.This study provides a facile strategy for synthesizing recyclable biomass-based high-performance epoxy vitrimers and carbon fiber composites.展开更多
The woven basalt fiber composites(WBFC) and the unidirectional [0°/90°/45°/-45°]s basalt fiber composites(UBFC) were prepared by hot-pressing.Three-point bending test,low velocity impact test,and b...The woven basalt fiber composites(WBFC) and the unidirectional [0°/90°/45°/-45°]s basalt fiber composites(UBFC) were prepared by hot-pressing.Three-point bending test,low velocity impact test,and ballistic test were performed to the prepared composites.After the tests,the specimens were recovered and analyzed for micromorphology.Three-point bending tests show that both the bending strength and stiffness of the WBFC surpass those of the UBFC.Low velocity impact test results show that the low velocity impact resistance to hemispherical impactor of the UBFC is higher than that of the WBFC,but the low velocity impact resistance to sharp impactor of the UBFC is lower than that of the WBFC.For the ballistic test,it can be found that the ballistic property of the UBFC is higher than that of the WBFC. After the tests,microscopic analysis of the specimens was applied,and their failure mechanism was discussed.The main failure modes of the UBFC are delamination and fibers breakage under the above loading conditions while the main failure mode of the WBFC is fibers breakage.Although delamination damage can be found in the WBFC under the above loading conditions,the degree of delamination is far less than that of the UBFC.展开更多
Natural rubber grafted maleic anhydride （NR-g-MAH） was synthesized by mixing maleic anhydride （MAH） and natural rubber （NR） in solid state in a torque rheometer using dicurnyl peroxide （DCP） as initiator. Then...Natural rubber grafted maleic anhydride （NR-g-MAH） was synthesized by mixing maleic anhydride （MAH） and natural rubber （NR） in solid state in a torque rheometer using dicurnyl peroxide （DCP） as initiator. Then the self-prepared NR-g-MAH was used as a compatibilizer in the natural rubber/short nylon fiber composites. Both the fimctionalization of NR with MAH and the reaction between the modified rubber and the nylon fiber were confirmed by Fourier transform infrared spectroscopy （FTIR）. Composites with different nylon short fiber loadings （0, 5, 10, 15 and 20 phr） were compounded on a two-roll mill, and the effects of the NR-g-MAH on the tensile and thermal properties, fiber-rubber interaction, as well as the morphology of the natural rubber/short nylon fiber composites were investigated. At equal fiber loading, the NR-g-MAH compatibilized NR/short nylon fiber composites showed improved tensile properties, especially the tensile modulus at 100% strain which was about 1.5 times that of the corresponding un-compatibilized ones. The equilibrium swelling tests proved that the incorporation of NR-g-MAH increased the interaction between the nylon fibers and the NR matrix. The crosslink density measured with NMR techniques showed that the NR-g-MAH compatiblized composites had lower total crosslink density. The glass transition temperatures of the compatibilized composites were about 1 K higher than that of the corresponding un-compabilized ones. Morphology analysis of the NR/short nylon fiber composites confirmed NR-g-MAH improved interfacial bonding between the NR matrix and the nylon fibers. All these results signified that the NR-g-MAH could act as a good compatilizer of NR/short nylon fiber composites and had a potential for wide use considering its easy to be prepared and compounded with the composites.展开更多
Carbon fiber(C_(f))reinforced pyrolytic carbon(PyC)composites simultaneously possessing robust mechanical strength,excellent friction performances and outstanding anti-ablation properties are demanded for advanced aer...Carbon fiber(C_(f))reinforced pyrolytic carbon(PyC)composites simultaneously possessing robust mechanical strength,excellent friction performances and outstanding anti-ablation properties are demanded for advanced aerospace applications.Efficient architecture design and optimization of composites are promi-nent yet remain high challenging for realizing the above requirements.Herein,binary reinforcements of networked silicon nitride nanowires(Si_(3)N_(4) nws)and interconnected graphene(GE)have been successfully constructed into C f/PyC by precursor impregnation-pyrolysis and chemical vapor deposition.Notably,net-worked Si_(3)N_(4) nws are uniformly distributed among the carbon fibers,while interconnected GE is firmly rooted on the surface of both networked Si_(3)N_(4) nws and carbon fibers.In the networked Si_(3)N_(4) nws and interconnected GE reinforced C_(f)/PyC,networked Si_(3)N_(4) nws significantly boost the cohesion strength of PyC,while GE markedly improves the interface bonding of both Si_(3)N_(4) nws/PyC and fiber/PyC.Benefiting from the synergistic reinforcement effect of networked Si_(3)N_(4) nws and interconnected GE,the C_(f)/PyC have a prominent enhancement in mechanical(shear and compressive strengths increased by 119.9% and 52.84%,respectively)and friction(friction coefficient and wear rate reduced by 25.40% and 60.10%,respectively)as well as anti-ablation(mass ablation rate and linear ablation rate decreased by 71.25% and 63.01%,respectively).This present strategy for networked Si_(3)N_(4) nws and interconnected GE reinforced C_(f)/PyC provides a dominant route to produce mechanically robust,frictionally resisting and ablatively resistant materials for use in advanced aerospace applications.展开更多
In this work, a flame-retardant polypropylene（PP）/ramie fiber（RF） composite was prepared. The ramie fibers were wrapped chemically by a phosphorus- and nitrogen-containing flame retardant（FR） produced via in sit...In this work, a flame-retardant polypropylene（PP）/ramie fiber（RF） composite was prepared. The ramie fibers were wrapped chemically by a phosphorus- and nitrogen-containing flame retardant（FR） produced via in situ condensation reaction so as to suppress their candlewick effect. Fourier transform infrared spectroscopy（FTIR）, X-ray photoelectron spectroscopy（XPS） and scanning electron microscopy（SEM） demonstrated that the ramie fibers wrapped chemically by FR（FR-RF） were obtained successfully. Thermogravimatric test showed that the PP/FR-RF composite had more residue and better thermal stability at high temperatures than the PP/RF composite. Cone calorimeter（CC） results indicated that the peak of heat release rate（PHRR） and total heat release（THR） correspondingly decreased by 23.4% and 12.5% compared with the values of neat PP/RF. The PP/FR-RF composite created a continuous and compact char layer after the combustion. Combining FTIR analysis of char residue after CC test with heat conduction coefficient results, it could be concluded that the charring of FR on RF greatly weakened the candlewick effect of RF, and more char residue in the RF domain facilitated the formation of more continuous and compact char layer in the whole combustion zone, consequently protected PP composites during combustion, resulting in the better flame retardancy of PP/FR-RF composite than that of PP/RF composite.展开更多
A constitutive model is constructed to consider the resin matrix post-yield softening and progressive hardening behaviors. A user-defined material mechanical behavior （UMAT） subroutine is created, then the non-linea...A constitutive model is constructed to consider the resin matrix post-yield softening and progressive hardening behaviors. A user-defined material mechanical behavior （UMAT） subroutine is created, then the non-linear three-dimensional finite element analysis on the tensile processes of multi-fiber composites is conducted. The approximate 45° shear bands emanating from the matrix crack tip are found, being coincided with the experimental observations. The shear stress on the adjacent intact fiber/matrix interface is strongly influenced by the shear band and thus the stress concentration factor （SCF） changes obviously in the adjacent fibers. The distinct stress redistribution in the adjacent intact fibers implies the significant effect of the shear bands on the progressive fiber fracture initiation. As the inter-fiber spacing increases, the peak value of the SCF in the adjacent intact fiber decreases, whereas the overload zone becomes wider. The research has provided a helpful tool to evaluate the failure of fiber composites and optimize the composite performance through the proper selection of resin matrix properties and fiber volume fraction.展开更多
In order to explore the bonding failure mechanism of high modulus carbon fiber composite materials,the tensile experiment and finite element numerical simulation for single-lap and bevel-lap joints of unidirectional l...In order to explore the bonding failure mechanism of high modulus carbon fiber composite materials,the tensile experiment and finite element numerical simulation for single-lap and bevel-lap joints of unidirectional laminates are carried out,and the stress distributions,the failure modes,and the damage contours are analyzed. The analysis shows that the main reason for the failure of the single-lap joint is that the stress concentration of the ply adjacent to the adhesive layer is serious owing to the modulus difference,and the stress cannot be effectively transmitted along the thickness direction of the laminate. When the tensile stress of the ply exceeds its ultimate strength in the loading process,the surface fiber will fail. Compared with the single-lap joint,the bevel-lap joint optimizes the stress transfer path along the thickness direction,allows each layer of the laminate to share the load,avoids the stress concentration of the surface layer,and improves the bearing capacity of the bevel-lap joint. The improved bearing capacity of the bevellap joint is twice as much as that of the single-lap joint. The research in this paper provides a new idea for the subsequent study of mechanical properties of adhesively bonded composite materials.展开更多
In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in har...In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in harsh seawater conditions is a concern. Researchers address this by exploring three approaches: coating fiber surfaces, hybridizing fibers and matrices with or without nanofillers, and interply rearrangement. This study focuses on evaluating the synergistic effects of interply rearrangement of glass/carbon fibers and hybrid nanofillers, specifically Multi-walled carbon nanotubes (MWCNT) and Halloysite nanotubes (HNT). The aim is to enhance impact properties by minimizing moisture absorption. Hybrid nanocomposites with equal-weight proportions of two nanofillers: 0 wt.%, 1 wt.%, and 2 wt.% were exposed to seawater for 90 days. Experimental data was subjected to modelling through the application of Predictive Fick’s Law. The study found that the hybrid composite containing 2 wt.% hybrid nanofillers exhibited a 22.10% increase in impact performance compared to non-modified counterparts. After 90 days of seawater aging, the material exhibited enhanced resistance to moisture absorption (15.74%) and minimal reduction in impact strength (8.52%) compared to its dry strength, with lower diffusion coefficients.展开更多
Insufficient interfacial activity and poor wettability between fibers and matrix are the two main factors limiting the improvement of mechanical properties of Carbon Fiber Reinforced Plastics(CFRP).Owl feathers are kn...Insufficient interfacial activity and poor wettability between fibers and matrix are the two main factors limiting the improvement of mechanical properties of Carbon Fiber Reinforced Plastics(CFRP).Owl feathers are known for their unique compact structure;they are not only lightweight but also strong.In this study,an in-depth look at owl feathers was made and it found that owl feathers not only have the macro branches structure between feather shafts and branches but also have fine feather structures on the branches.The presence of these fine feather structures increases the specific surface area of the plume branches and allows neighboring plume branches to hook up with each other,forming an effective mechanical interlocking structure.These structures bring owl feathers excellent mechanical properties.Inspired by the natural structure of owl feathers,a weaving technique and a sizing process were combined to prepare bionic Carbon Fiber(CF)fabrics and then to fabricate the bionic CFRP with structural characteristics similar to owl feathers.To evaluate the effect of the fine feather structure on the mechanical properties of CFRP,a mechanical property study on CFRP with and without the fine feather imitation structure were conducted.The experimental results show that the introduction of the fine feather branch structure enhance the mechanical properties of CFRP significantly.Specifically,the tensile strength of the composites increased by 6.42%and 13.06%and the flexural strength increased by 8.02%and 16.87%in the 0°and 90°sample directions,respectively.These results provide a new design idea for the improvement of the mechanical properties of the CFRP,promoting the application of CFRP in engineering fields,such as automotive transportation,rail transit,aerospace,and construction.展开更多
Hypersonic vehicles are subjected to critical aerodynamic heating during flight,which poses a substantial challenge for the design of thermal protection systems(TPSs).Carbon-bonded carbon fiber(CBCF)composites are hig...Hypersonic vehicles are subjected to critical aerodynamic heating during flight,which poses a substantial challenge for the design of thermal protection systems(TPSs).Carbon-bonded carbon fiber(CBCF)composites are highly valuable materials for TPS in aerospace and military applications because of their lightweight structure and exceptional dimensional stability at elevated temperatures.However,these methods are constrained by a limited capacity for in-plane heat dissipation,which restricts their application under extreme thermal gradients.Therefore,incorporating enhanced in-plane directional heat-leading capabilities into CBCF composite designs represents a highly innovative approach that is expected to alleviate local thermal stress and achieve efficient thermal management.Herein,we propose a multifunctional design strategy involving the fabrication of SiBCN-modified carbon-bonded carbon fiber(CBCF/SiBCN)composites through the integration of high-efficiency in-plane heat conduction pathways with anisotropic thermal insulation structures.The preparation process,microscopic morphology,mechanical response and thermal performance of the CBCF/SiBCN composites were systematically investigated.The fabricated samples exhibited the compressive strength of 4.05-4.36 MPa in the in-plane direction and 1.30-1.36 MPa in the through-the-thickness direction,while maintaining the low density of 0.48-0.49 g·cm^(-3).Notably,the in-plane thermal conductivity of CBCF/SiBCN reached 60.9-61.5 W·m^(−1)·K^(−1)while remaining at 0.08 W·m^(−1)·K^(−1)in the direction of thermal insulation,demonstrating typical anisotropy and indicating significant potential for effective thermal management.This paper introduces an innovative design that focuses on the development of inplane directional heat-leading properties for thermally insulating composites,which potentially meet the critical requirements for thermal protection in aerospace applications.展开更多
Embedding optical fiber sensors into composite materials offers the advantage of real-time structural monitoring.However,there is an order-of-magnitude difference in diameter between optical fibers and reinforcing fib...Embedding optical fiber sensors into composite materials offers the advantage of real-time structural monitoring.However,there is an order-of-magnitude difference in diameter between optical fibers and reinforcing fibers,and the detailed mechanism of how embedded optical fibers affect the micromechanical behavior and damage failure processes within composite materials remains unclear.This paper presents a micromechanical simulation analysis of composite materials embedded with optical fibers.By constructing representative volume elements(RVEs)with randomly distributed reinforcing fibers,the optical fiber,the matrix,and the interface phase,the micromechanical behavior and damage evolution under transverse tensile and compressive loads are explored.The study finds that the presence of embedded optical fibers significantly influences the initiation and propagation of microscopic damage within the composites.Under transverse tension,the fiber-matrix interface cracks first,followed by plastic cracking in the matrix surrounding the fibers,forming micro-cracks.Eventually,these cracks connect with the debonded areas at the fiber-matrix interface to form a dominant crack that spans the entire model.Under transverse compression,plastic cracking first occurs in the resin surrounding the optical fibers,connecting with the interface debonding areas between the optical fibers and the matrix to form two parallel shear bands.Additionally,it is observed that the strength of the interface between the optical fiber and the matrix critically affects the simulation results.The simulated damage morphologies align closely with those observed using scanning electron microscopy(SEM).These findings offer theoretical insights that can inform the design and fabrication of smart composite materials with embedded optical fiber sensors for advanced structural health monitoring.展开更多
This research explores the water uptake behavior of glass fiber/epoxy composites filled with nanoclay and establishes an Artificial Neural Network(ANN)to predict water uptake percentage fromexperimental parameters.Com...This research explores the water uptake behavior of glass fiber/epoxy composites filled with nanoclay and establishes an Artificial Neural Network(ANN)to predict water uptake percentage fromexperimental parameters.Composite laminates are fabricated with varying glass fiber(40-60 wt.%)and nanoclay(0-4 wt.%)contents.Water absorption is evaluated for 70 days of immersion following ASTM D570-98 standards.The inclusion of nanoclay reduces water uptake by creating a tortuous path for moisture diffusion due to its high aspect ratio and platelet morphology,thereby enhancing the composite’s barrier properties.The ANN model is developed with a 3-4-1 feedforward structure and learned through the Levenberg-Marquardt algorithm with soaking time(7 to 70 days),fiber content(40,50,and 60 wt.%)and nanoclay content(0,2,and 4 wt.%)as input parameters.The model’s output is the water uptake percentage.The model has high prediction efficiency,with a correlation coefficient(R)of 0.998 and a mean squared error of 1.38×10^(-4).Experimental and predicted values are in excellent agreement,ensuring the reliability of the ANN for the simulation of nonlinear water absorption behavior.The results identify the synergistic capability of nanoclay and fiber concentration to reduce water absorption and prove the feasibility of ANN as a substitute for time-consuming testing in composite durability estimation.展开更多
The poor surface antibacterial properties are one of the important factors limiting the application of Carbon Fibers Reinforced Polyetheretherketone (CFR-P) composites as artificial bone replace materials. Some of the...The poor surface antibacterial properties are one of the important factors limiting the application of Carbon Fibers Reinforced Polyetheretherketone (CFR-P) composites as artificial bone replace materials. Some of the Two-Dimensional (2D) nanomaterials with unique lamellar structures and biological properties have been demonstrated to have excellent antibacterial properties. Antibacterial properties can be improved by feasible chemical strategies for preparing 2D nanomaterials coating on the surface of CFR-P. In this work, Black Phosphorus (BP) coating was prepared on the originally chemically inert CFR-P surface based on wet chemical pretreatment. The physical and chemical properties, including surface microstructure, chemical composition and state, roughness and hydrophilicity were characterized. The antibacterial ratios against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Streptococcus mutans (S. mutans) were evaluated. The results indicated that hydrophilicity of BP coating on CFR-P was significantly higher compared to that of the pure CFR-P. Wet chemical pretreatment using mixed acid reagents (concentrated sulfuric acid and concentrated nitric acid) introduced hydroxyl, carboxyl and nitro groups on CFR-P. The BP coating exhibited the antibacterial rate of over 98% against both S. aureus and E. coli. In addition, the antibacterial rate of BP coating against the main pathogenic bacteria of dental caries, Streptococcus mutans, reached 45%.展开更多
Carbon fiber/phenolic resin composites have great potential application in the field of electronic information,where excellent structural-functional integration is required.In this work,the establishment of interfacia...Carbon fiber/phenolic resin composites have great potential application in the field of electronic information,where excellent structural-functional integration is required.In this work,the establishment of interfacial structures consisting of carbon nanotubes with different morphologies at the fiber/matrix interface is conducive to the further modulation of the mechanical,tribological,electromagnetic interference(EMI)shielding and thermal conductivity properties of carbon fiber/phenolic resin composites.Specially,array carbon nanotubes can deep into the resin matrix,effectively hindering crack extension,and constructing an electrically and thermally conductive network.Compared with the carbon fiber/phenolic composites,the tensile strength and modulus of elasticity(163.86±9.60 MPa,5.06±0.25 GPa)of the array carbon nanotubes reinforced carbon fiber/phenolic composites were enhanced by 57.09%and 22.22%.The average friction coefficient and wear rate(0.20±0.02,1.11×10^(-13)±0.13×10^(-13)m^(3)N^(−1)m^(−1))were reduced by 39.39%and 74.31%.EMI shielding effectiveness up to 40 dB in the X-band at 0.4 mm sample thickness,diffusion coefficient(0.39±0.003 mm^(2)/s)and thermal conductivity(0.54±0.004 W/(m K))were enhanced by up to 14.37%and 50.42%.This study reveals the beneficial effects of morphological changes of carbon nanotubes on the design of interfacial structure,proposes the reinforcement mechanism of array carbon nanotubes,and opens up the prospect of carbon fiber/phenolic composites for electronic applications.展开更多
Fiber reinforced ceramic matrix composites(FRCMCs)are the preferred materials for safety critical components in the fields of aerospace,nuclear engineering,and transportation,with broad market and application prospect...Fiber reinforced ceramic matrix composites(FRCMCs)are the preferred materials for safety critical components in the fields of aerospace,nuclear engineering,and transportation,with broad market and application prospects.However,due to the characteristics of multiphase,heterogeneity,and anisotropy,key issues such as poor adhesion,high porosity,and crack propagation urgently need to be addressed in the fabrication and machining of FRCMCs.With the increasing demand for FRCMCs parts,high-quality and reliable design and fabrication,performance evaluation,and precision manufacturing have become a series of hot issues.There is a lack of systematic review in capturing the current research status and development direction of FRCMCs fabrication and machining.This research aims to comprehensively review and critically evaluate the existing understanding of the fabrication and machining of FRCMCs.This study can provide scientists with a deeper understanding of the shape control mechanism of FRCMCs fabrication and machining,the theoretical basis of material synchronous removal,machining performance,and development direction.Firstly,the basic characteristics and application background of FRCMCs are introduced.Secondly,by comparing and analyzing the typical fabrication process of FRCMCs,the advantages,disadvantages,and performance evaluation of different processes are comprehensively evaluated.Thirdly,the material removal mechanisms and machining performance evaluation standards of traditional mechanical machining technologies(drilling,milling,grinding)and non-traditional mechanical machining technologies(ultrasonic,laser,water jet,discharge,wire saw,and multi-field hybrid machining)are discussed and analyzed.Finally,the challenges,development trends,and prospects faced by FRCMCs in the fields of fabrication,machining,and application are analyzed.This study not only elucidates the basic processes and key difficulties in the fabrication of FRCMCs,but also provides valuable insights for low-damage machining.展开更多
Carbon fiber reinforced ultra-high temperature ceramic （UHTC） composites, consisting of carbon fibers embedded in a UHTC-matrix or a C-SiC-UHTC-matrix, are deemed as the most viable class of materials that can overc...Carbon fiber reinforced ultra-high temperature ceramic （UHTC） composites, consisting of carbon fibers embedded in a UHTC-matrix or a C-SiC-UHTC-matrix, are deemed as the most viable class of materials that can overcome the poor fracture toughness and thermal shock resistance of monolithic UHTC ma- terials, and also improve the oxidation resistance and ablation resistance of C/C and C/SiC composites at ultra-high temperatures. In this review, we summarize the different processing routes of the compos- ites based on the UHTC introducing methods, including chemical vapor infiltration/deposition （CVI/D）, precursor infiltration and pyrolysis （PIP）, reactive melt infiltration （RMI）, slurry infiltration （SI）. in-sito reaction, hot pressing （HP）, etc; and the advantages and drawbacks of each method are briefly dis- cussed. The carbon fiber reinforced UHTC composites can be highly tailorable materials in terms of fiber. interface, and matrix. From the perspective of service environmental applications for engine propul- sions anti hypersonic vehicles, the material designs （mainly focusing on the composition, quantity, structure of matrix, as well as the architecture of carbon fibers, UHTCs and pores）, their relevant processing routes and properties （emphasizing on the mechanical and ablation properties） are discussed in this paper. In addition, we propose a material architecture to realize the multi-function through changing the distri- bution of carbon fibers, UHTCs and pores, which will be an important issue for future development of carbon fiber reinforced UHTC composites.展开更多
The achievement of both robust fire-safety and mechanical properties is of vital requirement for carbon fiber(CF)composites.To this end,a facile interracial strategy for fabricating flame-retardant carbon fibers decor...The achievement of both robust fire-safety and mechanical properties is of vital requirement for carbon fiber(CF)composites.To this end,a facile interracial strategy for fabricating flame-retardant carbon fibers decorated by bio-based polyelectrolyte complexes(PEC)consisting of chitosan(CH)and ammonium polyphosphate(APP)was developed,and its corresponding fire-retarded epoxy resin composites(EP/(PEC@CF))without any other additional flame retardants were prepared.The decorated CFs were characterized by SEM-EDX,XPS and XRD,indicating that the flame-retardant PEC coating was successfully constructed on the surface of CF.Thanks to the nitrogen-and phosphorous-containing PEC,the resulting composites exhibited excellent flame retardancy as the limiting oxygen index(LOI)increased from 31.0%of EP/CF to 40.5%and UL-94 V-0 rating was achieved with only 8.1 wt%PEC.EP/(PEC8.1@CF)also performed well in cone calorimetry with the decrease of peak-heat release rate(PHRR)and smoke production rate(SPR)by 50.0%and 30.4%,respectively,and the value of fire growth rate(FIGRA)was also reduced to 3.41 kW·m-2-s-1 from 4.84 kW·m-2·s-1,suggesting a considerably enhanced fire safety.Furthermore,SEM images of the burning residues revealed that the PEC coating exhibited the dominant flame-retardant activity in condensed phase via the formation of compact phosphorus-rich char.In addition,the impact strength of the composite was improved,together with no obvious deterioration of flexural properties and glass transition temperature.Taking advantage of the features,the PEC-decorated carbon fibers and the relevant composites fabricated by the cost-effective and facile strategy would bring more chances for widespread applications.展开更多
基金supported by the Key Research and Development Plan of Shaanxi Province(No.2023-GHZD-12)the Chinese Aeronautical Establishment Aeronautical Science Foundation(No.20230041053006)the National Natural Science Foundation of China(Nos.12472392 and 12172304).
文摘3D printing has emerged as an advanced manufacturing technique for carbon fiber reinforced composites and relevant structures that endure significant dynamic loads in engineering applications.The dynamic behavior of these materials,primarily influenced by the dynamic fiber pullout interface strength necessitates investigation into the rate-dependent fiber/matrix interfacial strength.This study modifies a Hopkinson tension bar to conduct dynamic pullout tests on a single fiber bundle,utilizing a low-impedance bar and an in-situ calibrated semiconductor strain gauge to capture weak stress signals.Stress equilibrium analyses are performed to validate the transient dynamic loading on single fiber bundle specimens.The results reveal that the fiber/matrix interfacial strength is rate-dependent,increasing with the loading rate,while remaining unaffected by the embedded length.Fracture microstructural analyses show minimal fiber pullout due to high interfacial stresses induced by longer embedded lengths.Lastly,suggestions are made for the efficient design of fiber pullout experiments.
基金Project(51072235) supported by the National Natural Science Foundation of ChinaProject(11JJ1008) supported by the Natural Science Foundation of Hunan Province,China+2 种基金Project(20110162110044) supported by the PhD Program Foundation of Ministry of Education of ChinaProject(7433001207) supported by Hunan Provincial Innovation Foundation for Postgraduate,ChinaProject(2001JF3215) supported by Hunan Provincial Science and Technology Plan,China
文摘Piezoelectric materials are capable of actuation and sensing and have been used in a wide variety of smart devices and structures.Active fiber composite and macro fiber composite are newly developed types of piezoelectric composites,and show superior properties to monolithic piezoelectric wafer due to their distinctive structures.Numerous work has focused on the performance prediction of the composites by evaluation of structural parameters and properties of the constituent materials with analytical and numerical methods.Various applications have been explored for the piezoelectric fiber composites,including vibration and noise control,health monitoring,morphing of structures and energy harvesting,in which the composites play key role and demonstrate the necessity for further development.
文摘The morphological structure of various epoxies toughened with a special amorphous thermoplastic PEK-C and their carbon fiber composites were studied by using SEM. For both cases, phase separation and inversion took place to form fine epoxy-rich globules dispersing in the PEK-C matrix, in which the epoxy-rich phase had the absolutely higher volume fraction. The phase structure and the interfacial properties were also studied by means of FTIR, DSC, and DMTA as well. An accompanying mechanical determination revealed that an improved toughness was achieved both in the blend casts and in the carbon fiber composites. A composite structural model was hence suggested.
基金financially supported by the National Natural Science Foundation of China (Nos.51973118, 22175121,52003160 and 22001175)Key-Area Research and Development Program of Guangdong Province (Nos.2019B010941001 and2019B010929002)+7 种基金the Natural Science Foundation of Guangdong Province (No.2020A1515010644)the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(No.2019ZT08C642)Shenzhen Science and Technology Program (Nos.JCYJ20220818095810022, JSGGZD20220822095201003 and JCYJ20210324095412035)the start-up fund of Shenzhen University (No.000002110820)the Guangdong Natural Science Foundation (Nos.2022A1515011781 and2021A1515110086)Science and Technology Innovation Commission of Shenzhen,China (Nos.RCBS20200714114910141 and JCYJ20210324132816039)the Start-up Grant at Harbin Institute of Technology (Shenzhen),China (Nos.HA45001108 and HA11409049)Shenzhen Key Laboratory of Advanced Functional Carbon Materials Research and Comprehensive Application (No.ZDSYS20220527171407017)。
文摘The emerging biomass-based epoxy vitrimers hold great potential to fulfill the requirements for sustainable development of society.Since the existence of dynamic chemical bonds in vitrimers often reduces both the thermal and mechanical properties of epoxy resins, it is challenging to produce recyclable epoxy vitrimers with both excellent mechanical properties and good thermal stability. Herein, a monomer 4-(((5-(hydroxymethyl)furan-2-yl)methylene)amino)phenol(FCN) containing furan ring with potential to form high density of hydrogen bonding among repeating units is designed and copolymerized with glycerol triglycidyl ether to yield epoxy resin(FCN-GTE), which intrinsically has dual hydrogen bond networks, dynamic imine structure and resultant high performance. Importantly, as compared to the BPA-GTE, the FCN-GTE exhibits significantly improved mechanical properties owing to the increased density of hydrogen bond network and physical crosslinking interaction. Furthermore, density functional theory(DFT) calculation and in situ FTIR analysis is conducted to decipher the formation mechanism of hydrogen bond network. In addition, the FCN-GTE possesses superior UV shielding, chemical degradation, and recyclability because of the existence of abundant imine bonds. Notably, the FCN-GTE-based carbon fiber composites could be completely recycled in an amine solution.This study provides a facile strategy for synthesizing recyclable biomass-based high-performance epoxy vitrimers and carbon fiber composites.
基金supported by the National Science Foundation of China(No.51571033)supported in part by the National Natural Science Foundation of China under Grant No.11521062。
文摘The woven basalt fiber composites(WBFC) and the unidirectional [0°/90°/45°/-45°]s basalt fiber composites(UBFC) were prepared by hot-pressing.Three-point bending test,low velocity impact test,and ballistic test were performed to the prepared composites.After the tests,the specimens were recovered and analyzed for micromorphology.Three-point bending tests show that both the bending strength and stiffness of the WBFC surpass those of the UBFC.Low velocity impact test results show that the low velocity impact resistance to hemispherical impactor of the UBFC is higher than that of the WBFC,but the low velocity impact resistance to sharp impactor of the UBFC is lower than that of the WBFC.For the ballistic test,it can be found that the ballistic property of the UBFC is higher than that of the WBFC. After the tests,microscopic analysis of the specimens was applied,and their failure mechanism was discussed.The main failure modes of the UBFC are delamination and fibers breakage under the above loading conditions while the main failure mode of the WBFC is fibers breakage.Although delamination damage can be found in the WBFC under the above loading conditions,the degree of delamination is far less than that of the UBFC.
基金financially supported by the Joint Funds of the National Natural Science Foundation of China and Guangdong Province(No.U1134005)
文摘Natural rubber grafted maleic anhydride （NR-g-MAH） was synthesized by mixing maleic anhydride （MAH） and natural rubber （NR） in solid state in a torque rheometer using dicurnyl peroxide （DCP） as initiator. Then the self-prepared NR-g-MAH was used as a compatibilizer in the natural rubber/short nylon fiber composites. Both the fimctionalization of NR with MAH and the reaction between the modified rubber and the nylon fiber were confirmed by Fourier transform infrared spectroscopy （FTIR）. Composites with different nylon short fiber loadings （0, 5, 10, 15 and 20 phr） were compounded on a two-roll mill, and the effects of the NR-g-MAH on the tensile and thermal properties, fiber-rubber interaction, as well as the morphology of the natural rubber/short nylon fiber composites were investigated. At equal fiber loading, the NR-g-MAH compatibilized NR/short nylon fiber composites showed improved tensile properties, especially the tensile modulus at 100% strain which was about 1.5 times that of the corresponding un-compatibilized ones. The equilibrium swelling tests proved that the incorporation of NR-g-MAH increased the interaction between the nylon fibers and the NR matrix. The crosslink density measured with NMR techniques showed that the NR-g-MAH compatiblized composites had lower total crosslink density. The glass transition temperatures of the compatibilized composites were about 1 K higher than that of the corresponding un-compabilized ones. Morphology analysis of the NR/short nylon fiber composites confirmed NR-g-MAH improved interfacial bonding between the NR matrix and the nylon fibers. All these results signified that the NR-g-MAH could act as a good compatilizer of NR/short nylon fiber composites and had a potential for wide use considering its easy to be prepared and compounded with the composites.
基金financially supported by the National Natural Science Foundation of China(No.51872232)the Research Fund of the State Key Laboratory of Solidification Processing(NWPU),China(No.136-QP-2015)+4 种基金the“111”project of China(No.B08040)the National Training Program of Innovation and Entrepreneurship for Undergraduates(No.S202010699336)the Joint Funds of the National Natural Science Foundation of China(No.U21B2067)the Key Scientific and Technological Innovation Research Team of Shaanxi Province(No.2022TD-31)the Key R&D Program of Shaanxi Province(No.2021ZDLGY14-04).
文摘Carbon fiber(C_(f))reinforced pyrolytic carbon(PyC)composites simultaneously possessing robust mechanical strength,excellent friction performances and outstanding anti-ablation properties are demanded for advanced aerospace applications.Efficient architecture design and optimization of composites are promi-nent yet remain high challenging for realizing the above requirements.Herein,binary reinforcements of networked silicon nitride nanowires(Si_(3)N_(4) nws)and interconnected graphene(GE)have been successfully constructed into C f/PyC by precursor impregnation-pyrolysis and chemical vapor deposition.Notably,net-worked Si_(3)N_(4) nws are uniformly distributed among the carbon fibers,while interconnected GE is firmly rooted on the surface of both networked Si_(3)N_(4) nws and carbon fibers.In the networked Si_(3)N_(4) nws and interconnected GE reinforced C_(f)/PyC,networked Si_(3)N_(4) nws significantly boost the cohesion strength of PyC,while GE markedly improves the interface bonding of both Si_(3)N_(4) nws/PyC and fiber/PyC.Benefiting from the synergistic reinforcement effect of networked Si_(3)N_(4) nws and interconnected GE,the C_(f)/PyC have a prominent enhancement in mechanical(shear and compressive strengths increased by 119.9% and 52.84%,respectively)and friction(friction coefficient and wear rate reduced by 25.40% and 60.10%,respectively)as well as anti-ablation(mass ablation rate and linear ablation rate decreased by 71.25% and 63.01%,respectively).This present strategy for networked Si_(3)N_(4) nws and interconnected GE reinforced C_(f)/PyC provides a dominant route to produce mechanically robust,frictionally resisting and ablatively resistant materials for use in advanced aerospace applications.
基金financially supported by the National Natural Science Foundation of China(Nos.50933005 and 51121001)the Program for Changjiang Scholars and Innovative Research Team in Universities(IRT1026)
文摘In this work, a flame-retardant polypropylene（PP）/ramie fiber（RF） composite was prepared. The ramie fibers were wrapped chemically by a phosphorus- and nitrogen-containing flame retardant（FR） produced via in situ condensation reaction so as to suppress their candlewick effect. Fourier transform infrared spectroscopy（FTIR）, X-ray photoelectron spectroscopy（XPS） and scanning electron microscopy（SEM） demonstrated that the ramie fibers wrapped chemically by FR（FR-RF） were obtained successfully. Thermogravimatric test showed that the PP/FR-RF composite had more residue and better thermal stability at high temperatures than the PP/RF composite. Cone calorimeter（CC） results indicated that the peak of heat release rate（PHRR） and total heat release（THR） correspondingly decreased by 23.4% and 12.5% compared with the values of neat PP/RF. The PP/FR-RF composite created a continuous and compact char layer after the combustion. Combining FTIR analysis of char residue after CC test with heat conduction coefficient results, it could be concluded that the charring of FR on RF greatly weakened the candlewick effect of RF, and more char residue in the RF domain facilitated the formation of more continuous and compact char layer in the whole combustion zone, consequently protected PP composites during combustion, resulting in the better flame retardancy of PP/FR-RF composite than that of PP/RF composite.
基金financially supported by the National Key Basic Research Program of China(No.2010CB631102)the National Natural Science Foundation of China(Nos.51173100 and 51373090)the Natural Science Foundation of Shandong Province(No.JQ201016)
文摘A constitutive model is constructed to consider the resin matrix post-yield softening and progressive hardening behaviors. A user-defined material mechanical behavior （UMAT） subroutine is created, then the non-linear three-dimensional finite element analysis on the tensile processes of multi-fiber composites is conducted. The approximate 45° shear bands emanating from the matrix crack tip are found, being coincided with the experimental observations. The shear stress on the adjacent intact fiber/matrix interface is strongly influenced by the shear band and thus the stress concentration factor （SCF） changes obviously in the adjacent fibers. The distinct stress redistribution in the adjacent intact fibers implies the significant effect of the shear bands on the progressive fiber fracture initiation. As the inter-fiber spacing increases, the peak value of the SCF in the adjacent intact fiber decreases, whereas the overload zone becomes wider. The research has provided a helpful tool to evaluate the failure of fiber composites and optimize the composite performance through the proper selection of resin matrix properties and fiber volume fraction.
文摘In order to explore the bonding failure mechanism of high modulus carbon fiber composite materials,the tensile experiment and finite element numerical simulation for single-lap and bevel-lap joints of unidirectional laminates are carried out,and the stress distributions,the failure modes,and the damage contours are analyzed. The analysis shows that the main reason for the failure of the single-lap joint is that the stress concentration of the ply adjacent to the adhesive layer is serious owing to the modulus difference,and the stress cannot be effectively transmitted along the thickness direction of the laminate. When the tensile stress of the ply exceeds its ultimate strength in the loading process,the surface fiber will fail. Compared with the single-lap joint,the bevel-lap joint optimizes the stress transfer path along the thickness direction,allows each layer of the laminate to share the load,avoids the stress concentration of the surface layer,and improves the bearing capacity of the bevel-lap joint. The improved bearing capacity of the bevellap joint is twice as much as that of the single-lap joint. The research in this paper provides a new idea for the subsequent study of mechanical properties of adhesively bonded composite materials.
文摘In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in harsh seawater conditions is a concern. Researchers address this by exploring three approaches: coating fiber surfaces, hybridizing fibers and matrices with or without nanofillers, and interply rearrangement. This study focuses on evaluating the synergistic effects of interply rearrangement of glass/carbon fibers and hybrid nanofillers, specifically Multi-walled carbon nanotubes (MWCNT) and Halloysite nanotubes (HNT). The aim is to enhance impact properties by minimizing moisture absorption. Hybrid nanocomposites with equal-weight proportions of two nanofillers: 0 wt.%, 1 wt.%, and 2 wt.% were exposed to seawater for 90 days. Experimental data was subjected to modelling through the application of Predictive Fick’s Law. The study found that the hybrid composite containing 2 wt.% hybrid nanofillers exhibited a 22.10% increase in impact performance compared to non-modified counterparts. After 90 days of seawater aging, the material exhibited enhanced resistance to moisture absorption (15.74%) and minimal reduction in impact strength (8.52%) compared to its dry strength, with lower diffusion coefficients.
基金supported by the Science and Technology Development Program of Jilin Province(No.20240101122JC)and(No.20240101143JC)the Key Scientific and Technological Research and Development Projects of Jilin Provincial Science and Technology Department(Grant Number 20230201108GX)。
文摘Insufficient interfacial activity and poor wettability between fibers and matrix are the two main factors limiting the improvement of mechanical properties of Carbon Fiber Reinforced Plastics(CFRP).Owl feathers are known for their unique compact structure;they are not only lightweight but also strong.In this study,an in-depth look at owl feathers was made and it found that owl feathers not only have the macro branches structure between feather shafts and branches but also have fine feather structures on the branches.The presence of these fine feather structures increases the specific surface area of the plume branches and allows neighboring plume branches to hook up with each other,forming an effective mechanical interlocking structure.These structures bring owl feathers excellent mechanical properties.Inspired by the natural structure of owl feathers,a weaving technique and a sizing process were combined to prepare bionic Carbon Fiber(CF)fabrics and then to fabricate the bionic CFRP with structural characteristics similar to owl feathers.To evaluate the effect of the fine feather structure on the mechanical properties of CFRP,a mechanical property study on CFRP with and without the fine feather imitation structure were conducted.The experimental results show that the introduction of the fine feather branch structure enhance the mechanical properties of CFRP significantly.Specifically,the tensile strength of the composites increased by 6.42%and 13.06%and the flexural strength increased by 8.02%and 16.87%in the 0°and 90°sample directions,respectively.These results provide a new design idea for the improvement of the mechanical properties of the CFRP,promoting the application of CFRP in engineering fields,such as automotive transportation,rail transit,aerospace,and construction.
基金supported by the National Natural Science Foundation of China(Nos.52472063 and 12090031)supported by the Fundamental Research Funds for the Central Universities.
文摘Hypersonic vehicles are subjected to critical aerodynamic heating during flight,which poses a substantial challenge for the design of thermal protection systems(TPSs).Carbon-bonded carbon fiber(CBCF)composites are highly valuable materials for TPS in aerospace and military applications because of their lightweight structure and exceptional dimensional stability at elevated temperatures.However,these methods are constrained by a limited capacity for in-plane heat dissipation,which restricts their application under extreme thermal gradients.Therefore,incorporating enhanced in-plane directional heat-leading capabilities into CBCF composite designs represents a highly innovative approach that is expected to alleviate local thermal stress and achieve efficient thermal management.Herein,we propose a multifunctional design strategy involving the fabrication of SiBCN-modified carbon-bonded carbon fiber(CBCF/SiBCN)composites through the integration of high-efficiency in-plane heat conduction pathways with anisotropic thermal insulation structures.The preparation process,microscopic morphology,mechanical response and thermal performance of the CBCF/SiBCN composites were systematically investigated.The fabricated samples exhibited the compressive strength of 4.05-4.36 MPa in the in-plane direction and 1.30-1.36 MPa in the through-the-thickness direction,while maintaining the low density of 0.48-0.49 g·cm^(-3).Notably,the in-plane thermal conductivity of CBCF/SiBCN reached 60.9-61.5 W·m^(−1)·K^(−1)while remaining at 0.08 W·m^(−1)·K^(−1)in the direction of thermal insulation,demonstrating typical anisotropy and indicating significant potential for effective thermal management.This paper introduces an innovative design that focuses on the development of inplane directional heat-leading properties for thermally insulating composites,which potentially meet the critical requirements for thermal protection in aerospace applications.
基金funded by the National Key Research and Development Program of China(Grant No.2022YFB3402500)the National Natural Science Foundation of China(Grant No.12372129).
文摘Embedding optical fiber sensors into composite materials offers the advantage of real-time structural monitoring.However,there is an order-of-magnitude difference in diameter between optical fibers and reinforcing fibers,and the detailed mechanism of how embedded optical fibers affect the micromechanical behavior and damage failure processes within composite materials remains unclear.This paper presents a micromechanical simulation analysis of composite materials embedded with optical fibers.By constructing representative volume elements(RVEs)with randomly distributed reinforcing fibers,the optical fiber,the matrix,and the interface phase,the micromechanical behavior and damage evolution under transverse tensile and compressive loads are explored.The study finds that the presence of embedded optical fibers significantly influences the initiation and propagation of microscopic damage within the composites.Under transverse tension,the fiber-matrix interface cracks first,followed by plastic cracking in the matrix surrounding the fibers,forming micro-cracks.Eventually,these cracks connect with the debonded areas at the fiber-matrix interface to form a dominant crack that spans the entire model.Under transverse compression,plastic cracking first occurs in the resin surrounding the optical fibers,connecting with the interface debonding areas between the optical fibers and the matrix to form two parallel shear bands.Additionally,it is observed that the strength of the interface between the optical fiber and the matrix critically affects the simulation results.The simulated damage morphologies align closely with those observed using scanning electron microscopy(SEM).These findings offer theoretical insights that can inform the design and fabrication of smart composite materials with embedded optical fiber sensors for advanced structural health monitoring.
文摘This research explores the water uptake behavior of glass fiber/epoxy composites filled with nanoclay and establishes an Artificial Neural Network(ANN)to predict water uptake percentage fromexperimental parameters.Composite laminates are fabricated with varying glass fiber(40-60 wt.%)and nanoclay(0-4 wt.%)contents.Water absorption is evaluated for 70 days of immersion following ASTM D570-98 standards.The inclusion of nanoclay reduces water uptake by creating a tortuous path for moisture diffusion due to its high aspect ratio and platelet morphology,thereby enhancing the composite’s barrier properties.The ANN model is developed with a 3-4-1 feedforward structure and learned through the Levenberg-Marquardt algorithm with soaking time(7 to 70 days),fiber content(40,50,and 60 wt.%)and nanoclay content(0,2,and 4 wt.%)as input parameters.The model’s output is the water uptake percentage.The model has high prediction efficiency,with a correlation coefficient(R)of 0.998 and a mean squared error of 1.38×10^(-4).Experimental and predicted values are in excellent agreement,ensuring the reliability of the ANN for the simulation of nonlinear water absorption behavior.The results identify the synergistic capability of nanoclay and fiber concentration to reduce water absorption and prove the feasibility of ANN as a substitute for time-consuming testing in composite durability estimation.
基金support of the National Natural Science Foundation of China(61971301)In part by the Central Guidance on Local Science and Technology Development Fund of Shanxi Province under Grant YDZJSX2021A018+1 种基金Shanxi Province Higher Education Science and Technology Innovation Plan Project(2022L060)the Fundamental Research Program of Shanxi Province(Nos.202203021212227,202303021212082).
文摘The poor surface antibacterial properties are one of the important factors limiting the application of Carbon Fibers Reinforced Polyetheretherketone (CFR-P) composites as artificial bone replace materials. Some of the Two-Dimensional (2D) nanomaterials with unique lamellar structures and biological properties have been demonstrated to have excellent antibacterial properties. Antibacterial properties can be improved by feasible chemical strategies for preparing 2D nanomaterials coating on the surface of CFR-P. In this work, Black Phosphorus (BP) coating was prepared on the originally chemically inert CFR-P surface based on wet chemical pretreatment. The physical and chemical properties, including surface microstructure, chemical composition and state, roughness and hydrophilicity were characterized. The antibacterial ratios against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Streptococcus mutans (S. mutans) were evaluated. The results indicated that hydrophilicity of BP coating on CFR-P was significantly higher compared to that of the pure CFR-P. Wet chemical pretreatment using mixed acid reagents (concentrated sulfuric acid and concentrated nitric acid) introduced hydroxyl, carboxyl and nitro groups on CFR-P. The BP coating exhibited the antibacterial rate of over 98% against both S. aureus and E. coli. In addition, the antibacterial rate of BP coating against the main pathogenic bacteria of dental caries, Streptococcus mutans, reached 45%.
基金supported by the National Natural Science Foundation of China(No.51872232)the Key Scientific and Technological Innovation Research Team of Shaanxi Province(No.2022TD-31)the Key R&D Program of Shaanxi Province(No.2021ZDLGY14-04).
文摘Carbon fiber/phenolic resin composites have great potential application in the field of electronic information,where excellent structural-functional integration is required.In this work,the establishment of interfacial structures consisting of carbon nanotubes with different morphologies at the fiber/matrix interface is conducive to the further modulation of the mechanical,tribological,electromagnetic interference(EMI)shielding and thermal conductivity properties of carbon fiber/phenolic resin composites.Specially,array carbon nanotubes can deep into the resin matrix,effectively hindering crack extension,and constructing an electrically and thermally conductive network.Compared with the carbon fiber/phenolic composites,the tensile strength and modulus of elasticity(163.86±9.60 MPa,5.06±0.25 GPa)of the array carbon nanotubes reinforced carbon fiber/phenolic composites were enhanced by 57.09%and 22.22%.The average friction coefficient and wear rate(0.20±0.02,1.11×10^(-13)±0.13×10^(-13)m^(3)N^(−1)m^(−1))were reduced by 39.39%and 74.31%.EMI shielding effectiveness up to 40 dB in the X-band at 0.4 mm sample thickness,diffusion coefficient(0.39±0.003 mm^(2)/s)and thermal conductivity(0.54±0.004 W/(m K))were enhanced by up to 14.37%and 50.42%.This study reveals the beneficial effects of morphological changes of carbon nanotubes on the design of interfacial structure,proposes the reinforcement mechanism of array carbon nanotubes,and opens up the prospect of carbon fiber/phenolic composites for electronic applications.
基金supported by Key Laboratory of Higheffciency and Clean Mechanical Manufacture at Shandong University,Ministry of Education,the National Natural Science Foundation of China(Nos.52305484,52305475,and U23A20632)the China Postdoctoral Science Foundation(No.2024M761876)+7 种基金the Youth Innovation Team Program of Universities in Shandong Province(No.2024KJH166)the National Key Research and Development Program of China(No.2023YFC2413301)the Taishan Scholars Program(No.tsqn202408242)the Shandong Provincial Natural Science Foundation(Nos.ZR2022QE053 and ZR2022QE159)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515111124)the Major Scientific and Technological Innovation Project of Shandong Province(No.2023CXGC010207)the Major Basic Research of Shandong Provincial Natural Science Foundation(No.ZR2023ZD34)the talent research project for the pilot project of integrating science,education,and industries of Qilu University of Technology(Shandong Academy of Sciences)(No.2024RCKY009)。
文摘Fiber reinforced ceramic matrix composites(FRCMCs)are the preferred materials for safety critical components in the fields of aerospace,nuclear engineering,and transportation,with broad market and application prospects.However,due to the characteristics of multiphase,heterogeneity,and anisotropy,key issues such as poor adhesion,high porosity,and crack propagation urgently need to be addressed in the fabrication and machining of FRCMCs.With the increasing demand for FRCMCs parts,high-quality and reliable design and fabrication,performance evaluation,and precision manufacturing have become a series of hot issues.There is a lack of systematic review in capturing the current research status and development direction of FRCMCs fabrication and machining.This research aims to comprehensively review and critically evaluate the existing understanding of the fabrication and machining of FRCMCs.This study can provide scientists with a deeper understanding of the shape control mechanism of FRCMCs fabrication and machining,the theoretical basis of material synchronous removal,machining performance,and development direction.Firstly,the basic characteristics and application background of FRCMCs are introduced.Secondly,by comparing and analyzing the typical fabrication process of FRCMCs,the advantages,disadvantages,and performance evaluation of different processes are comprehensively evaluated.Thirdly,the material removal mechanisms and machining performance evaluation standards of traditional mechanical machining technologies(drilling,milling,grinding)and non-traditional mechanical machining technologies(ultrasonic,laser,water jet,discharge,wire saw,and multi-field hybrid machining)are discussed and analyzed.Finally,the challenges,development trends,and prospects faced by FRCMCs in the fields of fabrication,machining,and application are analyzed.This study not only elucidates the basic processes and key difficulties in the fabrication of FRCMCs,but also provides valuable insights for low-damage machining.
基金supported by the Major Program of Aerospace Advanced Manufacturing Technology Research Foundation NSFC and CASC, China (Grant No. U1537204)the Research Fund of Youth Innovation Promotion Association CAS, China (Grant No. 2014171)
文摘Carbon fiber reinforced ultra-high temperature ceramic （UHTC） composites, consisting of carbon fibers embedded in a UHTC-matrix or a C-SiC-UHTC-matrix, are deemed as the most viable class of materials that can overcome the poor fracture toughness and thermal shock resistance of monolithic UHTC ma- terials, and also improve the oxidation resistance and ablation resistance of C/C and C/SiC composites at ultra-high temperatures. In this review, we summarize the different processing routes of the compos- ites based on the UHTC introducing methods, including chemical vapor infiltration/deposition （CVI/D）, precursor infiltration and pyrolysis （PIP）, reactive melt infiltration （RMI）, slurry infiltration （SI）. in-sito reaction, hot pressing （HP）, etc; and the advantages and drawbacks of each method are briefly dis- cussed. The carbon fiber reinforced UHTC composites can be highly tailorable materials in terms of fiber. interface, and matrix. From the perspective of service environmental applications for engine propul- sions anti hypersonic vehicles, the material designs （mainly focusing on the composition, quantity, structure of matrix, as well as the architecture of carbon fibers, UHTCs and pores）, their relevant processing routes and properties （emphasizing on the mechanical and ablation properties） are discussed in this paper. In addition, we propose a material architecture to realize the multi-function through changing the distri- bution of carbon fibers, UHTCs and pores, which will be an important issue for future development of carbon fiber reinforced UHTC composites.
基金Financial supports by the National Natural Science Foundation of China(Nos.51773137 and 51721091)the Sichuan Province Youth Science and Technology Innovation Team(No.2017TD0006)
文摘The achievement of both robust fire-safety and mechanical properties is of vital requirement for carbon fiber(CF)composites.To this end,a facile interracial strategy for fabricating flame-retardant carbon fibers decorated by bio-based polyelectrolyte complexes(PEC)consisting of chitosan(CH)and ammonium polyphosphate(APP)was developed,and its corresponding fire-retarded epoxy resin composites(EP/(PEC@CF))without any other additional flame retardants were prepared.The decorated CFs were characterized by SEM-EDX,XPS and XRD,indicating that the flame-retardant PEC coating was successfully constructed on the surface of CF.Thanks to the nitrogen-and phosphorous-containing PEC,the resulting composites exhibited excellent flame retardancy as the limiting oxygen index(LOI)increased from 31.0%of EP/CF to 40.5%and UL-94 V-0 rating was achieved with only 8.1 wt%PEC.EP/(PEC8.1@CF)also performed well in cone calorimetry with the decrease of peak-heat release rate(PHRR)and smoke production rate(SPR)by 50.0%and 30.4%,respectively,and the value of fire growth rate(FIGRA)was also reduced to 3.41 kW·m-2-s-1 from 4.84 kW·m-2·s-1,suggesting a considerably enhanced fire safety.Furthermore,SEM images of the burning residues revealed that the PEC coating exhibited the dominant flame-retardant activity in condensed phase via the formation of compact phosphorus-rich char.In addition,the impact strength of the composite was improved,together with no obvious deterioration of flexural properties and glass transition temperature.Taking advantage of the features,the PEC-decorated carbon fibers and the relevant composites fabricated by the cost-effective and facile strategy would bring more chances for widespread applications.
