Carbon Fabric Reinforced Epoxy Composites Research Articles

Tribological properties of CNT-filled epoxy-carbon fabric composites: Optimization and modelling by machine learning

Polymer matrix composites reinforced with fibers/fillers are extensively used in several tribological components of automotive and boating applications. The mechanical performance of polymer composites improves by incorporating nanofillers as secondary reinforcement. The present research work fabricated carbon fabric-reinforced epoxy composites using the hand layup. The carbon fabric-reinforced polymer composites were fabricated with 0.1 wt%, 0.2 wt%, and 0.5 wt% of carbon nanotubes (CNT) fillers as secondary reinforcement. Tribological properties of carbon fabric-reinforced epoxy composites filled with CNT have been carried out using a pin‐on‐disc method. Adding fillers significantly improves the tribological behaviour of the carbon fabric-reinforced epoxy composites by reducing wear rate and coefficient of friction. The large surface area of interaction due to the higher aspect ratio of CNT shows improved adhesion between epoxy matrix and carbon fabrics. It improves the various mechanical and tribological characteristics of composites—also, an analysis of worn surfaces is carried out to analyze the wear mechanisms using scanning electronic microscopy. The research employs a combination of experimental analyses and machine learning (ML) techniques to explore the wear resistance, hardness, and predictive modeling of volume loss in the composites. The hyperparameter fine-tuning of ML algorithms, including Random Forest (RF), k-Nearest Neighbors (KNN), and XGBoost, demonstrates superior predictive capabilities, particularly with RF. The study bridges material science, ML, and practical applications, contributing valuable insights for developing advanced composite materials.

Investigation of tensile properties, hardness, and morphology of h-BN and MoS 2 filler modified carbon fabric/epoxy composites

The present study aims to improve the tensile and hardness properties of carbon fabric–reinforced epoxy composite (CFEC) by using hexagonal boron nitride (h-BN) and molybdenum disulfide (MoS2) fillers. Magnetic stirring and ultrasonication were used to disperse fillers in epoxy resin. CFEC, h-BN filled CFEC and MoS2 filled CFEC fabricated as per hand layup and vacuum bag technique. The tensile strength of CFEC was remarkably improved up to 6 wt.% h-BN and MoS2 addition separately in the resin matrix. The maximum tensile strength of 486 MPa and Young’s modulus of 44 GPa were noticed in 6 wt.% h-BN incorporated CFEC displaying 59% and 47% improvements, respectively. The maximum toughness is shown by 6 wt.% MoS2 incorporated CFEC indicating 102% improvement. The uniformly dispersed high-performance filler in the epoxy effectively transferred stress, improving tensile properties. However, filler agglomerates, stress-raising spots, and poor filler–matrix interaction beyond 6 wt.% filler reduced the tensile property improvement. The introduction of h-BN and MoS2 in the composite increased hardness, with 6 wt.% h-BN added CFEC recording the highest hardness denoting 23% greater than the neat CFEC.

Influence of hBN and MoS2 fillers on toughness and thermal stability of carbon fabric-epoxy composites

Hexagonal boron nitride (hBN) and molybdenum disulfide (MoS2) fillers of 2 to 8 wt.% influence on toughness, microhardness and thermal stability of carbon fabric-reinforced epoxy composite (CFREC) reported. Mode-I, mixed-mode I/II toughness and microhardness of CFREC improved due to the addition of hBN and MoS2 separately upto 6 wt.% filler loading. The epoxy matrix in CFREC modified by hBN and MoS2 strengthens the matrix, deflects the crack path and resists delamination. Toughness reduced beyond 6 wt.% filler addition due to agglomeration and poor fiber-filler-matrix bonding as revealed by the surface morphology of the fracture specimen. Thermal analysis reveals decomposition temperature at 25% weight loss increased from 395 to 430 °C and 395 to 411 °C due to 4 wt.% MoS2 and 4 wt.% hBN addition to CFREC respectively. Impermeable characteristics of MoS2 and hBN fillers caused tortuous diffusion path for gas molecules and delayed thermal decomposition.

Fracture Toughness of CNT Filled Carbon Fabric Reinforced Epoxy Composites

ABSTRACT In the present investigation, hand layup processed composites and hot-pressed Carbon matrix reinforced composites were manufactured with and without the addition of carbon nanotubes. The fabricated composites were tested for its mechanical and fracture properties using ASTM testing standards. The results showed that the carbon nanotubes reinforced composites have shown improved tensile and fracture properties when compared with carbon fabric reinforced epoxy composites. The main focus of the present investigation is to study the role and effect of CNT filler as a secondary reinforcement to carbon fibre reinforced epoxy composites. The results of these investigations provide insight into of fracture behaviour of CNT filled carbon fibre reinforced epoxy composites under autoclave chamber.

Thermomechanical Properties of Carbon Fabric Reinforced Epoxy Laminates with h-BN and MoS2 Fillers

Abstract This work endeavors to investigate thermomechanical performance of carbon fabric reinforced epoxy composite (CEC) with fillers – hexagonal boron nitride (h-BN) and molybdenum disulfide (MoS2). The filler of 2, 4, 6, and 8 Wt.% was dispersed precisely in the epoxy resin through magnetic stirring and ultrasonication, prepared the filler loaded CEC using vacuum bag technique and studied the composite behavior at an elevated temperature by dynamic mechanical analysis. The 6 Wt.% MoS2-CEC showed 70% enhancement of storage modulus since the filler in the epoxy networks increased the composite stiffness. The increase in G-band intensity of Raman spectra in the filler loaded composites confirmed the improved matrix-fiber stress transfer. The 4 Wt.% BN-CEC revealed the highest glass-transition temperature 92°C. The thermogravimetric analysis of the composite exhibited a two-step thermal decomposition: epoxy matrix (nearby 260°C) and carbon fibers (beyond 420°C). The 4 Wt.% MoS2-CEC showed the maximum degree of crosslinking, twice the neat CEC, the MoS2 restrained the mobility of the epoxy chains and decreased the thermal decomposition. Both the filler loaded composites have comparable thermal stability and are significantly improved than the neat CEC. Thus, the composite containing solid lubricant filler up to 6 Wt.% shall be used for high-temperature applications.

Impact of nano-silicon dioxide on mechanical properties of carbon fabric reinforced epoxy composites

Nanoparticles could improve the mechanical properties of polymer based composites due to synergy of higher filler-matrix interaction and better load transfer from matrix to the fillers. Epoxy resin has high strength and modulus, and good adhesion strength, which makes it attractive for several industrial applications. To improve interfacial bonding between epoxy and silicon dioxide (SiO2), surface treatment of SiO2 is done using acetone and silane coupling agents. To improve SiO2 dispersion in epoxy matrix, the epoxy matrix is modified by mixing with amine containing liquid rubber. Ultrasonication process has been used for uniform mixing of SiO2 in the modified epoxy resin. Carbon fabric reinforced epoxy (CF/Ep) composite with surface treated nano- SiO2 are fabricated using vacuum bagging technique followed by hot press. The effect of silane treated nano- SiO2 with varying filler loadings from 0.5 to 3 wt% on the static mechanical properties such as hardness, tensile, and flexural properties are characterized following ASTM standards. The experimental results show that the inclusion of silane coupling agent increased the interfacial bonding between nano- SiO2 particles and the epoxy resin so that the surface hardness, tensile and flexural properties are improved.

Investigation on cryogenic interlaminar shear properties of carbon fabric/epoxy composites improved by graphene oxide-coated glass fibers

In this work, carbon fabric-reinforced epoxy (CF/EP) composites reinforced by graphene oxide-coated short glass fibers (GO/SGF) were manufactured and characterized. The interlaminar shear strength (ILSS) of CF/EP composites at room temperature (RT) and cryogenic temperature (77K) was compared, and the enhancement mechanism was revealed through the analysis of microstructure. The result shows that bonding via hydrogen bonding with GO improved the compatibility of the SGF in the epoxy matrix. The ILSS of the composite reached the maximum value at the content of 0.4wt% GO/SGF, and increased by 24.3% and 21.3% at RT and 77K, respectively. The improvement on the interlaminar shear performance is attributed to the bearing of transverse shear force by the SGF between the composite layers.

Cryogenic Compression Properties and Failure Mechanism of Lightweight 3D MWK Carbon Fabric Reinforced Epoxy Composites

Lightweight 3D MWK carbon fabric reinforced epoxy composites are fabricated successfully. The compressive experiments on the 3D MWK carbon/epoxy composites with different fiber architecture are performed in three directions (longitudinal, transverse and in-plane) at room and liquid nitrogen temperature (low as -196 °C). Macro-Fracture morphology and SEM micrographs are examined to understand the deformation and failure mechanism. The results show 3D MWK carbon/epoxy composites have extremely compression properties at cryogenic temperature. The stress-strain curves and compression properties at liquid nitrogen temperature are improved significantly than those at room temperature. Meanwhile, the properties decrease with the increase of fiber orientation angle at room and cryogenic temperatures. Moreover, the compression properties are different in the longitudinal, in-plane and transverse direction. The results also show matrix is solidified and fiber/matrix interface adhesion is enhanced at cryogenic temperature and the main failure modes of material behave as fiber layers delaminating, fibers and bulk matrix shear fracture. In addition, the failure mechanism can be significantly affected by the temperature, fiber architecture and load mode.

Role of Metallic Nanofillers on Mechanical and Tribological Behaviour of Carbon Fabric Reinforced Epoxy Composites

In this study, hybrid composites based on carbon fabric and epoxy (C/Ep) were fabricated by hand lay-up method followed by compression moulding. The C/Ep with optimum carbon fiber (60 wt%) was chosen as a reference material, and to it, the metallic nanoparticles like aluminum (Al) and zinc (Zn) of different wt% (0.5 and 1.0) were included as secondary fillers. To understand the synergism effect of these hybrid reinforcements, mechanical properties and tribological behavior of composites were studied. From the test results, it was proved that hybridization improved the mechanical and tribological properties. The C/Ep consisting of 0.5 wt% Zn and Al showed higher tensile properties in comparison with all other fabricated composites. Increase in flexural strength and flexural modulus also observed as the filler content increased in C/Ep composite. Higher impact strength is noted at 1 wt% Zn filled C/Ep composite. Wear test data revealed that 0.5 wt% Zn in C/Ep has got superior wear resistance. Wear mechanisms were discussed using scanning electron micrographs of selected worn surfaces of the composites.

Effects of multi-walled carbon nanotube and nanosilica on tensile properties of woven carbon fabric-reinforced epoxy composites fabricated using VARIM

The effects of multi-walled carbon nanotubes (MWCNTs) and nanosilica on tensile behavior of woven carbon fabric-reinforced epoxy composites have been studied. Multi-scale composites with epoxy matrices modified with different MWCNT and nanosilica contents (0.1, 0.5 and 0.9 wt.%) have been fabricated by vacuum-assisted resin infusion molding (VARIM). The dispersion of the nanoparticles in the epoxy resin has been made using an ultrasound and high-speed shearing method. Incorporation of nanoparticles improved tensile behavior and this effect was more evident in the case of composites reinforced with 0.5 wt.% of MWNCT and nanosilica. Incorporating either of the tow nanoparticles at 0.9 wt.% leads to a decrease in the trend of tensile properties. Examination of fracture surfaces using scanning electron microscopy (SEM) showed that by incorporating 0.9 wt.% of each nanoparticle, there are local MWCNT and nanosilica agglomerations within the composites. These nanoparticle-agglomerates reduced their potential strengthening effect in multi-scale composites containing 0.9 wt.% of nanoparticles. Also, SEM images showed that the MWCNTs and nanosilica enhanced the fiber–matrix interfacial strength and then by toughening the surrounding matrix, improved the strength and stiffness of multi-scale composites.

Friction and Wear Behavior of Carbon Fabric-Reinforced Epoxy Composites

Besides intrinsic material properties, weight/energy savings and wear performance play an important role in the selection of materials for any engineering application. The tribological behavior of carbon fabric-reinforced epoxy composites produced by molding technique was investigated using a reciprocating pin-on-plate configuration. It was shown that the wear rate considerably decreased (by a factor of approx. 8) with the introduction of the reinforcing carbon fabric into the epoxy matrix. It was observed that the wear rate of the tested composites increased with an increase in normal load. Moreover, the coefficient of friction for epoxy/steel and composites/steel tribo-pairs was also determined and decreased with increasing load. By means of scanning electron microscopy of the wear tracks, different wear mechanisms such as matrix wear, matrix fatigue and cracking, matrix debris formation for neat epoxy together with fabric/fiber thinning, fabric breakage and fabric/matrix debonding for the reinforced epoxy could be distinguished.

Investigation of long-term water absorption behavior of carbon fabric reinforced epoxy composites containing hydrophobic nanosilica

hydrophobic filler containing epoxy matrix composites was investigated by keeping them in distilled water for 9 months. Aerosil R812 (8 nm) and Aerosil R972 (12 nm) were utilized at 3{\%} and 5{\%} w/w filler to resin ratio and the resin/filler mixture was combined with 12-ply carbon fabric to get 15 $\times $ 15 cm samples. Samples were molded under a hot press and for each sample 50 test samples obtained by cutting them with a water jet. The obtained samples were characterized by TG, FTIR, and SEM. The effect of water absorption was evaluated by measuring percentage water absorption and flexural strength of samples over 9 months. The results revealed that filler addition lowers the damage created by distilled water a considerable amount and addition of hydrophobic fillers to epoxy matrix composites can be especially beneficial for applications where long-term water exposure is desired.

Erosive Wear Behaviour of Carbon Fiber-reinforced Epoxy Composite

In the present investigation, solid particle erosion behaviour of unfilled and graphite particulate filled carbon fabric reinforced epoxy composites have been evaluated using silica sand particles as the erodent at different impact angles. The influence of filler content and impact angle on erosion rate of carbon epoxy composite is studied. Unfilled and graphite filled carbon epoxy composites exhibited semi-ductile erosive wear behaviour with maximum wear rate observed at 45° impingement angle. Unfilled composite exhibited better erosive wear resistance than the graphite filled ones. Erosive wear weight loss increased from 0 to 4% graphite filled composite; where as it decreased for 6% filled ones. The morphology of eroded surfaces was examined by using Scanning Electron Microscopy. Possible erosion mechanisms are discussed.

Optimization of tribological parameters in abrasive wear mode of carbon-epoxy hybrid composites

Abrasive wear performance of fabric reinforced composites filled with functional fillers is influenced by the properties of the constituents. This work is focused on identifying the factors such as filler type, filler loading, grit size of SiC paper, normal applied load and sliding distance on two-body abrasive wear behaviour of the hybrid composites. Abrasive wear tests were carried on carbon fabric reinforced epoxy composite (C-E) filled with filler alumina (Al2O3) and molybdenum disulphide (MoS2) separately in different proportions, using pin-on-disc apparatus. The experiments were planned according to Taguchi L18 orthogonal array by considering five factors, one at two levels and the remaining at three levels, affecting the abrasion process. Grey relational analysis (GRA) was employed to optimize the tribological parameters having multiple-response. Analysis of variance (ANOVA) was employed to determine the significance of factors influencing wear. Also, the comparative specific wear rates of all the composites under dry sliding and two-body abrasive wear were discussed. The analysis showed that the filler loading, grit size and filler type are the most significant factors in controlling the specific wear rate of the C-E composite. Optimal combination of the process parameters for multi performance characteristics of the composite under study is the set with filler type as MoS2, filler loading of 10wt.%, grit size 320, load of 15N and sliding distance of 30m. Further, the optimal parameter setting for minimum specific wear rate, coefficient of friction and maximum hardness were corroborated with the help of scanning electron micrographs.

Parametric appraisal of erosion behaviour of organo-modified montmorillonite-filled epoxy hybrid composites by Taguchi approach

In the present work, the influence of organo-modified montmorillonite loading on the solid particle erosion of carbon fabric-reinforced epoxy composites was investigated. The development of a multi-component composite system consisting of thermoset epoxy resin reinforced with carbon fabric and organo-modified montmorillonite nanoparticles, the erosion behaviour was studied for various erodent size, impact velocity, loading of organo-modified montmorillonite and for different impingement angles. For this purpose, erosion test rig and the design of experiments approach utilizing Taguchi’s orthogonal arrays were used. Of all the above factors, the erodent size has the greatest effect on the reduction in the erosion wear rate. The erosion wear rate variation was found to be in the range of 1.33 × 10−4–48.02 × 10−4 g/g. The lowest erosion wear rate was found in the case of unfilled carbon fabric-reinforced epoxy composite under erodent size of 600 µm, impact velocity of 30 m/s and erodent time of 1 min. Further, the results showed strong dependence of the erosive wear on the erodent size. The organo-modified montmorillonite filled carbon fabric-reinforced epoxy composite showed brittle erosion behaviour with maximum weight loss at 75° impingement angle. Analysis of variance was performed on the measured data and signal to noise ratios were found. The morphology of eroded surfaces was examined using scanning electron microscopy and damage mechanisms were discussed.

Effect of fiber surface on flexural strength in carbon fabric reinforced epoxy composites

The effect of carbon fiber surface characteristics on flexural properties of structural composites is studied in this work. Two types of intermediate modulus carbon fibers were used: T800HB and IM7. Results revealed that higher mechanical properties are linked with higher interfacial adhesion. Morphologies and chemical compositions of commercial carbon fibers (CF) were characterized by Fourier Transformed Infra Red (FTIR) and Scanning Electronic Microscopy (SEM). Comparing the results, the T800HB apparently has more roughness, since the IM7 seems to be recovered for a polymeric film. On other hand, the IM7 one shows higher interactivity with epoxy resin system Cycom 890 RTM. Composites produced with Resin Transfer Molding (RTM) were tested on a flexural trial. Interfacial adhesion difference was showed with SEM and Dynamic Mechanical Analyses (DMA), justifying the higher flexural behavior of composites made with IM7 fibers.

Mechanical and abrasive wear behavior of carbon fabric reinforced epoxy composite with and without fly ash cenospheres

Carbon fabric reinforced epoxy and carbon fabric reinforced epoxy containing different weight fraction of silane-treated fly ash cenospheres filled composites were cast, sectioned, and subjected to three-body abrasive wear tests for evaluating the abrasive wear behavior. Mechanical characterization was done and a comparison was made between the different samples. Abrasive wear tests were performed on a rubber wheel abrasion tester under different loads, abrading distances using quartz and silica sand as abrasives. The results showed that both unfilled carbon fabric reinforced epoxy and fly ash cenospheres filled carbon fabric reinforced epoxy composites exhibit differing magnitudes of wear volume loss, it being highest for unfilled carbon fabric reinforced epoxy composite. The data trends point to the fact that the wear volume and specific wear rate decreases with increasing fly ash cenospheres loading in carbon fabric reinforced epoxy composites. It was found that silane-treated fly ash cenospheres could effectively reduce the wear rate especially under silica sand as abrasives. To explain these differences, the worn surfaces were examined using scanning electron microscope and the features thus observed were correlated with the selected mechanical properties.

Single-Walled Carbon Nanotube Incorporated Novel Three Phase Carbon/Epoxy Composite with Enhanced Properties

In the present work, single-walled carbon nanotubes were dispersed within the matrix of carbon fabric reinforced epoxy composites in order to develop novel three phase carbon/epoxy/single-walled carbon nanotube composites. A combination of ultrasonication and high speed mechanical stirring at 2000 rpm was used to uniformly disperse carbon nanotubes in the epoxy resin. The state of carbon nanotube dispersion in the epoxy resin and within the nanocomposites was characterized with the help of optical microscopy and atomic force microscopy. Pure carbon/epoxy and three phase composites were characterized for mechanical properties (tensile and compressive) as well as for thermal and electrical conductivity. Fracture surfaces of composites after tensile test were also studied in order to investigate the effect of dispersed carbon nanotubes on the failure behavior of composites. Dispersion of only 0.1 wt% nanotubes in the matrix led to improvements of 95% in Young's modulus, 31% in tensile strength, 76% in compressive modulus and 41% in compressive strength of carbon/epoxy composites. In addition to that, electrical and thermal conductivity also improved significantly with addition of carbon nanotubes.

Development of carbon nanofibre incorporated three phase carbon/epoxy composites with enhanced mechanical, electrical and thermal properties

Vapour-grown carbon nanofibres (CNFs) were dispersed in the matrix of carbon fabric reinforced epoxy composites in order to develop carbon/epoxy/CNF three phase composites. A detailed investigation was carried out on the various techniques for dispersing CNFs in an epoxy resin such as ultrasonication, high speed mechanical stirring and the use of solvent, surfactant and higher temperature. An appropriate dispersion technique was selected based on the extent of CNF dispersion and its effect on the mechanical properties of CNF/epoxy two phase composites. Dispersion of only 0.5 wt.% vapour-grown CNF in the matrix using the optimized dispersion route resulted in significant improvement in the mechanical, thermal and electrical properties of three phase composites.

Dry Sliding Wear Behaviour of Carbon Fabric-Reinforced Epoxy Composite with and without Silicon Carbide

Carbon fabric-reinforced epoxy composites with and without silicon carbide filler were prepared by hand lay-up technique followed by compression moulding. These composites were tested on a pin-on-disc wear tester. The dry sliding wear test conditions include different applied load and sliding velocity. In this study, friction and dry sliding wear behaviour of silicon carbide (SiC)-filled carbon fabric-reinforced epoxy (C-E) composites were investigated. The weight fraction of SiC filler was varied (0, 5 and 10 wt%) so as to obtain composite samples of three different compositions. Sliding wear experiments were conducted using a pin-on-disc wear tester. The tests were conducted at a fixed sliding distance by varying the applied load and sliding velocity. The results show that for increased load and sliding velocity, higher wear loss was recorded. Excellent wear characteristics were obtained with C-E containing SiC as filler. Especially, 10 wt% of SiC in C-E gave a low wear rate. Moreover, the results reveal that 5 and 10 wt% of SiC in C-E showed 21 and 35 percentage of increase, respectively, in the wear resistance as compared with unfilled C-E composite. The wear resistance of the C-E and SiC-filled C-E composites was found to be related to the stability of the transfer film on the counterface. Moreover, incorporation of SiC in C-E showed improved mechanical properties. The results have been supplemented with scanning electron micrographs to help understand the possible wear mechanisms.