Fabrication Of Composite Materials Research Articles

Epoxy Composites with Reduced Graphene Oxide-Cellulose Nanofiber Hybrid Filler and Their Application in Concrete Strain and Crack Monitoring.

Advances in nanotechnology have provided approaches for the fabrication of new composite materials for sensing. Flexible sensors can make up for the shortcomings of traditional strain sensors in monitoring the surface strain and cracks of concrete structures. Using reduced graphene oxide (RGO) as a conductive filler, cellulose nanofiber (CNF) as a dispersant and structural skeleton, and waterborne epoxy (WEP) as a polymer matrix, a flexible composite material with piezoresistive effect was prepared by the solution blending and solvent evaporation method. The mechanical, electrical, and electromechanical properties of the composite were investigated. The results show that CNF can significantly improve the dispersion of RGO in the WEP matrix and help to form stable reinforcing and conductive networks, leading to great changes in the mechanical properties and resistivity of the composite. The composite film can withstand large deformations (>55% strain), and the resistance change rate demonstrates a high sensitivity to mechanical strain with a gauge factor of 34–71. Within a 4% strain range, the piezoresistive property of the composite is stable with good linearity and repeatability. The performance of the flexible film sensor made of the composite is tested and it can monitor the strain and crack of the concrete surface well.

Fabrication of durable and roughness-regeneration superhydrophobic composite materials by hot pressing

The practical applications of superhydrophobic materials are still limited due to the fragile micro-nano scale rough structures. Here a novel preparation method based on a new roughness-regeneration model is reported to fabricate durable and non-fluorinated superhydrophobic materials, through combining organosilicon functionalized Al2O3 (SiF–Al2O3) microparticles and low-cost bakelite powder (solid-resin). The effect of the blend ratio of SiF–Al2O3/solid-resin on superhydrophobic properties of composite material was investigated in this paper. The material surface can retain superhydrophobicity after a series of rigorous durability testing, such as broken area test, sandstorm test, sandpaper abrasion test, knife scratch test and cold-resistant test. Even if the fine sandpaper (5000 Cw) is applied, a higher surface roughness can still be maintained (Sa = 2.1 μm) and the superhydrophobicity (WCA = 151°) of the surface is reserved.

Aluminum-Matrix Natural Composite Material Based on the Al–Ca–Ni–La–Fe System

The primary crystallization concentration region of the aluminum solid solution (Al) is refined using computational analysis in the Thermo-Calc program, including the construction of liquidus surfaces and polythermal sections of the Al–Ca–Ni–La–Fe system, as well as experimental microstructural analysis using scanning electron microscopy. This region can be considered promising for the formation of new aluminum-matrix natural eutectic-type composite materials containing above 20 vol % of intermetallic particles in the structure. The investigation into the microstructure of a promising composition with the formula, wt %, Al–4Ca–2Ni–1La–0.6Fe revealed that it contains up to 23 vol % of Al4Ca and Al9FeNi intermetallic phases of a eutectic nature according to the calculation. Separate crystals of these phases in the eutectic composition have submicron sizes, notably, a length of 250–400 nm and a thickness of 100–200 nm. It is also established that no formation of the Al4La intermetallic phase predicted by the thermodynamic calculation is observed, while lanthanum itself is completely dissolved in the Al4Ca calcium-containing phase. An analysis of the microstructure and hardness during stepped annealing has shown that codoping of the Al–4Ca–2Ni–1La–0.6Fe alloy by zirconium and scandium (0.2% Zr and 0.1% Sc) leads to precipitation hardening due to the decomposition of the (Al) solid solution and further formation of coherent nanoparticles of the L12 phase—Al3(Zr, Sc) up to 20 nm in size. The results of studying the mechanical properties under uniaxial tension testing of cylindrical castings of the Al–4Ca–2Ni–1La–0.6Fe–0.2Zr–0.1Sc alloy show a relatively high level of strength characteristics (σв of 265 MPa and σ0.2 of 177 MPa) with the conservation of the elongation acceptable for the composite material (~2%). Thus, it is shown based on these results that the Al–Ca–Ni–La–Fe system is promising for the fabrication of new aluminum-matrix natural composite materials.

Optimization of drilling parameters of untreated JFRP PU foam sandwich by Taguchi method

Many researchers have studied the fabrication of composite materials and their mechanical and thermomechanical properties and applications. In contrast, limited work in the field of machining of composite materials has been reported in the literature. The aim of this work is to optimize the drilling parameters such as speed, feed rate and drill diameter using a high-speed steel (HSS) twist drill and a titanium aluminum nitrate (TAN)-coated carbide twist with a drill angle of 118°. The present experimental work has been carried out using Taguchi design analysis of L27 orthogonal array on jute-fiber-reinforced plastic polyurethane (JFRP PU) foam sandwich composites. A coordinate measuring machine was used to measure the drilled hole diameter to optimize the quality of the drilled hole with the combination of drilling parameters. Minitab 16 was used to investigate the variance (analysis of variance) of the test, which led to determining the significance of each parameter on drilling. The results clearly show that the HSS-twist-drilled hole exhibited a minimum thrust force of 90 N at a 3 mm dia. hole with a feed of 80 mm/min, a speed of 1500 revolutions per minute (rpm) and a torque of 0·14 N m. In contrast, the TAN-coated-carbide-drilled hole exhibited a thrust force of 88 N at a 3 mm dia. hole with a feed rate of 80 mm/min, a speed of 1500 rpm and a torque of 0·13 N m. Regression analysis evidently showed that drill diameter has the most significant effect, feed rate has a marginally significant effect and speed does not have any significant effect on minimizing the thrust force for both HSS- and TAN-drilled holes. However, the influence of torque has a marginally smaller variation for TAN compared to that for HSS. Speed and drill diameter have the most significant effect on delamination of both entrance and exit holes using the HSS tool, whereas, for delamination of both the TAN-twist-drilled entrance and exit holes, drill diameter is a more significant factor compared to speed and feed.

Research of strength and conducting properties of composite material modified by carbon nanotubes

The article studies the fabrication mechanism of semiconducting composite polymer material based on methyl methacrylate, butyl methacrylate and methacrylic acid co-polymer doped with carbon nanotubes (CNT). A mechanism for fabrication of composite polymer material modified with carbon nanotubes has been developed, and experimental studies of the strength, electrical and physical characteristics of the materials obtained have been carried out.

Tribological and mechanical properties of AA6061 reinforced with SiC and graphite for automobile applications

Abstract The main objective of this work to reduce the wear rate of the brake drum material used for braking purpose. Aluminium alloy of AA6061 is reinforced with the reinforcement materials of Silicon Carbide and Graphite in the various proportions to study the Tribological Properties and Mechanical properties for the application of Automobiles. After the fabrication of composite material for the brake drum is tested by using pin-on disc equipment for friction wear and hardness is measured by using Impact test. SEM analysis is carried out to view the image of mixing of Proportions evenly in the fabricated material.

Facile Synthesis of Magnetic Activated Carbon Composite for Arsenic Adsorption

Porous activated carbon (AC) and magnetic iron oxide nanoparticles (NPs) are widely used for the removal of arsenic from water body. Fabrication of composite material of iron oxide NPs on the surface of porous AC can further enhance this activity for commercial application. In this research, a magnetic AC composite for arsenic adsorption was prepared by facile hydrothermal treatment of aqueous solution containing activated carbon obtained from lapsi seed stone, iron(II) chloride, polyvinylpyrrolidone (PVP) and ethanol. Several analytical techniques such as scanning electron microscopy (SEM), energy dispersive x-ray (EDX), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirmed the formation of magnetite (Fe3O4) nanoparticles on the surface of porous AC. The prepared materials were accessed for their arsenic adsorption capacity using arsenic (III) trioxide solution and found that composite Fe2O3/AC can remove the arsenic from water far more effectively than activated carbon alone. For 0.5 g/ltr loading of composite sample with contract time of 5 hours, the arsenic content was significantly reduced, which shows that as-fabricated composite can be used potentially for water treatment.

Influence of Flyash & Silicon Nitride on Mechanical & Tribological Properties of Aa 7075 Hybrid Composite

The main objective of this research work is to study the effect of Silicon Nitride (Si3N4) and Flyash on the mechanical and tribological properties of AA 7075 hybrid composite. The Stir casting technique has been used for the fabrication of composite material. sAA 7075 were reinforced with 2 wt. % of Silicon Nitride and 2.5, 5, 7.5 wt. % of Flyash. Pin-on-disc equipment is used to evaluate the wear rate of the base alloy and hybrid composite. Dry sliding wear test were performed with the contact load which is varied by 10, 20 & 30 N. Sliding velocity is varied by 1, 1.5 and 2 m/s. Sliding distance is kept constant at 1000 m. The Scanning Electron Microscope (SEM), Energy Dispersive X Ray Spectroscopy (EDAX) and X-ray diffraction (XRD) were used for the characterization of the composites. The maximum hardness of 173 HV is achieved for 5 wt% Flyash and 2 wt% of Silicon Nitride addition. The percentage increase in hardness is 155 % above the base metal. AA 7075 with the 5 wt % reinforcement of Flyash shows the minimum wear rate. With respect to the base the wear rate is reduced by 59 %.

Analysis of mechanical vibrations applied on a LPGFS smart composite polymer material

The response of a Long Period Grating Fibre Sensor embedded into polymer matrix of a smart composite material to applied mechanical vibrations is analysed by observing the spectral shifts, broadenings and splitting of the resonance absorption bands appearing into resulting transmission spectrum. The developed model aims to improve the engineering of smart composite material fabrication and the design of its applications in aeronautics, industry, medicine and defence. The Long Period Grating Fibre Sensor simulation model is developed considering the role of optical fibre micro-bending effects caused by mechanical vibrations applied to polymer matrix. The sensor is operated as the smart composite material feedback loop which provides the input signal for automation systems and/or for smart material monitoring. The results of the performed simulations are compared to experimental results reported in literature observing a good agreement.

Real-time Particle Size Analysis Using the Focused Beam Reflectance Measurement Probe for In Situ Fabrication of Polyacrylamide\u2013Filler Composite Materials

Real-time particle size analysis, using an engineered focused beam reflectance measurement (FBRM), was studied for the fabrication of chemical composite materials, applying various (inorganic/organic/biological) filler powders with polyacrylamide via the in situ polymerization production process at 80 °C for 24 h. The measured diameter dimensions, differential distribution functions and growth during reactive compound manufacturing technology were monitored by determining quantitative chord length, this being the altering scale use of FBRM technique. Materials characterizations such as formulation part-, scanning electron microscopy-, substance elemental- and complex Fourier-transform infrared spectroscopy analyses, supported well the successful structural preparation of differing-property constituent compositions. In addition, it was also observed that operations such as granulation, coating and filling, were involved in the design of stronger polymer–reinforcement components. A comparison of the surface area variation of montmorillonite (245 m2/g), alumina (236 m2/g) and residual biomass (0.8 m2/g) with their corresponding formed composites (112, 84 and 0.1 m2/g, respectively) revealed that the presence of thermoset plastic matrix results in a drop in interface due to a defined multiple step formation processing. Furthermore, thermal characterization of alumina and the developed nanocomposite materials confirmed, as expected, the interaction of the nanocomposite precursors.

Investigation of Impact Strength and Hardness of UHMW Polyethylene Composites Reinforced with Nano-Hydroxyapatite Particles Fabricated by Friction Stir Processing.

The impact strength and surface properties of polymeric materials are of critical importance in various engineering applications. Friction stir processing (FSP) is a novel method for the fabrication of composite materials with superior mechanical properties. The main objective of this study is to investigate the impact strength and Rockwell hardness of UHMW polyethylene composites reinforced with nano-hydroxyapatite particles fabricated through FSP. The spindle speed (ω), tool traverse speed (f), volume fraction (v) of strengthening material and shoulder temperature (T) were key processing parameters. The analysis of variance (ANOVA) indicated that the selected processing parameters were significant. Microscopic investigations unveiled that high levels of (v, f) and low levels of (T, ω) caused agglomeration of the reinforcing particles and induced voids and channels, which consequently reduced the impact strength and hardness of the manufactured composite. However, medium conditions of processing parameters exhibited better distribution of particles with minimum defects, and hence resulted in better mechanical properties. Finally, the models to predict the impact strength and hardness are proposed and verified. Sets of process parameters favorable to maximize the impact strength and Rockwell hardness were worked out, which were believed to increase the impact strength, Rockwell hardness number, and ultimate tensile strength by 27.3%, 5.7%, and 11.2%, respectively.

Evaluation of Wear Properties of Heat-treated Al 7075/Graphite Powder/Bagasse ash Hybrid Metal Matrix Composites

This research work investigated the in?uence of graphite powder on the wear behavior of Al 7075/Graphite Powder (Gr)/Bagasse ash (BA) hybrid composite. The investigation reveals the effectiveness of incorporation of graphite powder in the composite for gaining wear reduction. The Al 7075 (Aluminium alloy 7075) reinforced with graphite powder and Bagasse ash were investigated. The conventional liquid casting technique was used for the fabrication of composite material and subjected to T6 heat treatment. The reinforcement content was chosen as 1, 3, and 5wt. % of graphite powder to identify its potential for self-lubricating property under dry sliding conditions. Hybrid composite is processed at 1wt% of Gr with 2, 4 and 6wt% of BA. The effect of load on dry sliding wear rate and coefficient of friction performance of Al 7075 casting alloy and its composites was evaluated by using a pin-on-disc with two different loads with constant speed at room temperature. Wear tests were conducted by using pin on disc apparatus to evaluate the tribological behaviour of the composite and to determine the optimum content of graphite powder for its minimum wear rate. The wear rate decreases with addition of graphite powder content and reaches its minimum at 5wt. % graphite. The coefficient of friction decreases with addition of graphite content and was found to be minimum at wt. 5% graphite. The wear properties of the hybrid composites containing graphite exhibited the superior wear-resistance properties.

MXene/Co3O4 composite material: Stable synthesis and its enhanced broadband microwave absorption

Abstract Microwave absorbers serve the purpose to ensure the transmission efficiency and accuracy in 5G telecommunications. Two-dimensional MXene has great potential in absorbing microwave. In this study, MXene(Ti3C2Tx)/Co3O4 composites are successfully fabricated by a facile and stable hydrothermal treatment in concentrated strong base and Argon environment, followed by a one-step annealing process. Phase composition, chemical state of elements, morphology and structure of the new composite materials are studied by systematical characterization. It is revealed that adsorbed Na+ ions and terminations, which are generated at the interface during hydrothermal treatment in concentrated NaOH solution, can protect the Ti3C2Tx from being decomposed. The synthesis mechanism is also proposed for stable fabrication of other MXene-based composite materials. The MXene/Co3O4 composite is able to perform single-band absorption, multiband absorption and even broadband absorption in 2–18 GHz band by tuning its composition and thickness. Particularly, better than 90% absorption in a wide range of 10.8–17 GHz can be achieved with a thickness of just 2 mm. Enhanced wideband absorption originates from the multilayer structure, the surface defects, the conductivity of Ti3C2Tx and the capacitance structure of Co3O4. Ultrathin and broadband high absorption features make the material a promising candidate for future application.

Polyluminol Modified Carbon Nanotube Electrodes for Electrochemical Capacitors

Luminol exhibits electrochemical redox activity when electropolymerized on various substrates, and has been used for electrocatalysis and biosensors [1, 2]. This electrochemical behavior is due to the presence of different amine functional groups within the polymer structure. Recent studies have shown that introducing amine groups on a carbon surface improves the charge storage capacity and the conductivity of the obtained material [3]. Our work aims to leverage the electrochemical properties of polyluminol (Plum) for electrochemical capacitors (ECs). Firstly, the Plum was synthesized using a chemical approach and characterized using spectroscopic methods and electrochemical analyses. Secondly, the polymer was deposited on carbon nanotubes (CNT) to enhance the charge storage capacity for ECs. The chemical composition of the polymer was found to be a mixture of benzoid and quinoid segments, bonded via secondary (NH) or tertiary amine (=N-) groups, respectively. Such functionalities facilitated chemical, thermal, and electrochemical stability of the polymer. The composite electrode material was obtained by in-situ chemical polymerization of Plum on CNT. Morphological analyses of CNT confirmed the increase of the Plum thickness on CNT with polymerization time, reaching a saturation point of 6.5 nm. In addition, a 4x increase of charge storage capacity with good electrode stability was observed compared to bare CNT over a potential window of 1.2 V as seen in figure 1. Study of the redox reaction kinetics revealed a mostly capacitive contribution of the polymer on CNT. This work showed the successful surface modification and engineering of CNT using a simple and effective fabrication method, which is suitable for large-scale fabrication of composite electrode materials for ECs. G.-F. Zhang and H.-Y. Chen, Analytica Chimica Acta, 419, 25 (2000).A. Sassolas, L. J. Blum and B. D. Leca-Bouvier, Sensors and Actuators B: Chemical, 139, 214 (2009).N. Phattharasupakun, J. Wutthiprom, P. Suktha, N. Ma and M. Sawangphruk, Journal of The Electrochemical Society, 165, A609 (2018). Figure 1

Room-temperature fabrication of TiO2-PHEA nanocomposite coating with high transmittance and durable superhydrophilicity

Coatings with high transmittance and superhydrophilicity play an outstanding role in many practical applications such as antifogging, antifouling, self-cleaning, etc. The durability greatly affects their applications. In the current work, TiO2 organic nanocomposite coating with high transmittance and durable superhydrophilicity was prepared via the homogeneous compositing of modified anatase TiO2 nanoparticles (NPs) and hydroxyethyl acrylate (HEA) without any solvent. The curing process of coating and the formation of nanometer rough structure were carried out simultaneously under ultraviolet (UV) irradiation at room temperature. The composite coating exhibited an excellent intrinsic superhydrophilicity (water contact angle less than 3° in 0.45 s), high transmittance (above 90% in the visible wavelength), mechanical robustness, photocatalytic activity, anti-fogging and anti-fouling properties. The superhydrophilicity of the as-prepared nanocomposite coating could last for 330 days in the laboratory environment, which was quite a long time for maintaining the superhydrophilicity of TiO2 coatings in the literature reports. The durable superhydrophilicity is attributed to the enhancement of intrinsic hydrophilicity and the increase of surface roughness. The superhydrophilic TiO2-PHEA nanocomposite coating has a wide application prospect in solar cells, building and automobile antifogging glass, antifogging lens and other fields. The methodology proposed in this work can be applied to the fabrication of new superhydrophilic TiO2-polymeric composite materials using a low-cost, efficient and simple methodology.

An electrochemical outlook upon the gaseous ethanol sensing by graphene oxide-SnO2 hybrid materials

Breakthroughs in the synthesis of hybrid materials have led to the development of a plethora of chemiresistors that could operate at lower and lower temperatures. Herein, we report the fabrication of novel composite materials (SnO2-GO 4:1, 8:1 and 16:1) based on graphene oxide (GO) sheets decorated with tin dioxide nanoparticles, through a controlled chemical growth. We succeeded in obtaining widely spaced isles of the metal oxide on the carbonaceous material, thus enhancing the electron transfer process (i.e. favored convergent diffusion, as investigated through cyclic voltammetric analysis), which plays a pivotal role for the final sensing behavior. Indeed, only with SnO2-GO 16:1 sample, superior responses towards gaseous ethanol were observed both at 150 °C and at RT (by exploiting the UV light), with respect to pristine SnO2 and mechanically prepared SnO2(16)@GO material. Particularly, an improvement of the sensitivity (down to 10 ppb), response and recovery times (about of 60–70 s) was assessed. Besides, all the powders were finely characterized on structural (XRPD, FTIR and Raman spectroscopies), surface (active surface area, pores volume, XPS), morphological (SEM, TEM) and electrochemical (cyclic voltammetries) points of view, confirming the effective growth of SnO2 nanoparticles on the GO sheets.

Cryogels of carboxyalkylchitosans as a universal platform for the fabrication of composite materials

Here we report a new simple method for fabrication of supermacroporous beads and monoliths via cross-linking of carboxyalkylated chitosan derivatives with hexamethylene diisocyanate in aqueous solution at subzero temperature. These materials provide high filtration rate and good mass-transfer that in combination with high binding capacity toward metal ions allows their application as a universal platform for fabrication of composite catalysts, sorbents, and metal-affine chromatography stationary phases. Using N-(2-carboxyethyl)chitosan (CEC), we have demonstrated that optimum chitosan carboxylation degree for cryogels synthesis is close to 1.0. Cu(II)-chelated CEC cryogels have shown high efficiency as metal-affinity sorbents for ciprofloxacin recovery. Co(II)-chelated CEC cryogels have been used for fabrication of Co(II) ferrocyanide-containing composite with the distribution coefficient for 137Cs of 140,000 ml/g and the adsorption capacity of ˜1 mmol/g. Composite Pd-catalysts supported on CEC cryogel provided tenfold higher reaction rate in 4-nitrophenol reduction in comparison with Pd-catalyst supported on chitosan beads.

MECHANICAL CHARACTERIZATION OF GFRP/CFRP/NATURAL FIBER LAMINATED IN EPOXY RESIN COMPOSITE

Abstract The composite consisting of an epoxy resin matrix reinforce with E-type glass fiber, Carbon fiber, Natural Fiber are used due to their high strength, light weight and free from corrosion. This research work will describe the fabrication of nano composite materials. The fabrications of Epoxy/GFRP/CFRP/Natural Fiber by hand layup technique. To study the characterization of properties such as Mechanical properties and Morphological properties of Epoxy/GFRP/CFRP/Natural Fiber.

Fabrication and characterization of S glass hybrid composites for Tie rods of aircraft

Abstract This paper explains the fabrication of S-Glass epoxy composite hybrid composite materials from a combination of 7-mill glass fabric, ceramic paper as intermediate and carbon fabric. The ceramic papers which acted as intermediate layers are treated with a mixture of short carbon fibers and carbon powder along with epoxy, epoxy terminated butadiene acrylonitrile (ETBN) and room temperature hardener. The composites are fabricated using Hand lay-up process and solidification of material is obtained through high temperature oven. Further these composite materials are machined to obtain required dimensions as per the design of shield for Tie-rod and splitter rod by considering Radar Cross Section calculation. Flexural and Inter Laminar Shear Strength (ILSS) tests were performed on S-Glass epoxy composite before and after machining. Flexural and Inter Laminar Shear Strength (ILSS) tests were considered in fabrication of Radom structures. Deviations observed in ILSS are around 3% to 18% and deviations observed in Flexural tests are 16% to 23%. In Flexural tests, the samples after machining have positive affect. Whereas, in ILSS tests, the machined samples have least effect. The tests obtained in S-Glass epoxy composite before and after machining were in allowable deviations.

Fabrication and Mechanical Properties of Hybrid Composites between Pineapple fiber/Styrofoam Particle/Paper Tissue

Abstract In this research work, the fabrication and mechanical properties of hybrid composite materials between pineapple fiber/ styrofoam particle and paper tissue were studied. The local natural fiber, pineapple fiber was used with the recycle styrofoam particles to play role of dispersed phase whereas the recycle of paper tissue was used as matrix phase. The composites samples were fabricated via hand lay-up technique and examined the mechanical properties for example, tensile strength, compressive strength and bending. From the results, it could be seen that the sample of 25wt% and 30wt% loading exhibited the best mechanical properties whereas the 40wt% loading showed the exellent sound properties which very closed to commercial products.