Nanoparticle-reinforced Composites Research Articles

Performance analysis of wind turbine blades using E-Glass fiber and SiO2- Al2O3-TiO2 MMT nanocomposite with AW 106 epoxy

ABSTRACT In a wind turbine, blades are an essential component. In recognition of their remarkable qualities, nanoparticle-reinforced composites (also known as nanocomposites) are becoming increasingly popular among academics and companies. In preceding investigations of wind turbine blades, it was discovered that manufacturing issues, such as cracks in the supporting airfoil transition area, fiberglass, and hardener, were brought on by insufficient resin availability. For the effective investigation of wind turbine blades, a unique e-glass fiber and nanocomposite using AW 106 epoxy have been presented. The primary purpose of this research is on the viability of nanocomposites based on montmorillonite, specifically for use in wind turbine blades. The production and in-depth investigation of nano SiO2-Al2O3-TiO2 montmorillonite dispersed E-glass fiber/AW 106 epoxy composites are the subjects of the investigation of proposed method. The experimental findings were confirmed by GRA and SEM analysis in ANSYS to predict wind turbine blade failures, evaluate the blades’ hardness, and test the edge and flap loading conditions. As the result, demonstrated that nanocomposite has a tensile strength of Al2O3with 1% high with a value of 106 MPa, Al2O3with 1% withstands the highest number of failure cycles with 273, Rockwell number is 43, and the maximum value of Al2O3is 0.992 in GRA with various materials.

Steigmann-Ogden interface effect on the effective elastic properties of nanoparticle-reinforced composites: From nanocomposites to nanoparticles

Closed-form bound and estimate solutions to the effective elastic properties of nanoparticle-reinforced composites with Steigmann-Ogden interface effect are obtained based on composite sphere assemblage and generalized self-consistent method respectively. Compared with Maxwell-type approximation in the literature, the closed-form estimate solution to the effective shear modulus in this work is validated to fall inside the bound solutions. When the nanocomposite becomes the nanoparticle as the particle volume fraction is extremely high, the bounds of the effective shear modulus of the nanoparticle are unexpected to be distinct as a non-neutral inclusion. However, by properly adjusting the stretching and bending stiffness of the interface, it is found that the neutrality condition of the nanoparticle could be achieved which is generally impossible under transverse shear boundary conditions.

A novel numerical method for stochastic study of fiber-reinforced composites with nanoparticles under impact loading

Nanoparticle-reinforced composites have caught attention due to their enhanced properties and wide potential use. However, the uncertainty in the distribution of nanoparticles during the manufacturing poses several challenges when deterministic numerical methods are used to model their mechanical behavior, following a macro homogeneous approach. In this work, a stochastic numerical method based on finite element modeling is proposed to simulate the inhomogeneous distribution of nanoparticles inside the composite, focusing on low-velocity impact. Each element in the finite element model is regarded as a unit cell with a constant weight fraction of nanoparticles, while the random distribution of nanoparticles is described by a variable weight fraction among elements following a Gaussian distribution. This distribution is related to the mechanical behavior of the unit cell inside the model and it was defined based on material characterization tests for different nanoparticles weight fractions. To validate the proposed model, experimental low-velocity impact tests, at different energy levels, on composites reinforced with nanoparticles (0.5 wt.%) were carried out. The numerical method was assessed by comparing experimental results in terms of mechanical response and damage phenomena. The current numerical methodology was found to contribute to uncertainty investigation based on a mixed experimental-numerical analysis.

Mechanical properties of carbon fiber reinforced with carbon nanotubes and graphene filled epoxy composites: experimental and numerical investigations

The mechanical properties of carbon fiber-reinforced epoxy composites were identified by adding carbon-based nano-reinforcements, such as multi-wall carbon nanotubes (CNTs) and graphene platelets (GP), into the epoxy matrix by conducting suitable experiments. The main focus of this study is to compare the tensile modulus, tensile strength, flexural modulus, flexural strength, and thermal conductivity of carbon fiber-reinforced epoxy composites with nanoparticle reinforcement. The results revealed that adding CNTs and GP nanoparticles improved the mechanical properties compared to a pure carbon fiber-reinforced plastic composite. However, compared to CNTs, the GP’s addition has increased the mechanical properties of the CFRP composite. In addition, scanning electron microscopy (SEM) images were presented to explore the microstructural characterization of carbon fiber-reinforced nanoparticle-reinforced composites. Further, using numerical studies, the transverse modulus, major and minor Poisson’s ratio of the carbon fibre reinforced with CNT and GP particle reinforcement were estimated. The current study is applied to the efficient design of nanoparticle reinforced carbon fibre reinforced composites.

Interface Effects on the Viscoelastic Properties of PDMS/SiO2 Particle-Reinforced Nanocomposites

Abstract Polydimethylsiloxane/silica (PDMS/SiO2) particle-reinforced nanocomposites prepared at the present study are typical viscoelastic materials. Due to the high surface-to-volume ratio of the SiO2 nanoparticles, the interface effects on the overall properties of the nanocomposites cannot be ignored. In order to investigate the interface effects on the viscoelastic properties of the nanocomposites, a multiscale model is established in the present study, combining the molecular dynamics (MD) model of the interface at the nanoscale and the unit cell model of the nanocomposites at the mesoscale. In the MD model of the interface, the viscoelastic properties of the interphase region influenced by the interface are found to be different from that of the pure PDMS matrix and the bulk SiO2. Because the polymer chains subject to different restrictions existing in the interphase region, this region can possess high stiffness and damping properties simultaneously. The interphase parameters can be determined by the inverse multiscale simulation method, taking advantage of both the numerical model and the experimental results. Due to the interface effects, as demonstrated by the unit cell model, the dynamic shear moduli of the nanocomposites can be simultaneously improved by several times to an order of magnitude higher than that of the matrix, in consistent with experimental results. Thus, the mechanism of the interface effects enhancing the viscoelastic properties of the PDMS/SiO2 nanocomposites can be revealed in the present study, which can be useful for the design of viscoelastic nanocomposites with high stiffness and damping properties.

A Short Review of the Literature on the Multiscale Modeling of Nanoparticle-Reinforced Composites

A Short Review of the Literature on the Multiscale Modeling of Nanoparticle-Reinforced Composites

The effect of surface free energy on the fracture behaviors of nanoparticle-reinforced composites

By considering the surface free energy effect, an analytical investigation on the fracture behaviors of nanoparticle-reinforced composites was performed in this study. The plastic zones ahead of the crack tips based on the Irwin model were introduced in our analysis, which has a significant influence on the fracture toughness of inelastic structures, especially for polymer and metal matrix composites. Take copper and aluminum nanoparticles as examples, comprehensive parametric studies were conducted to investigate the interaction between a Griffith crack and the nearby nanoparticle. It was found that for nanoparticles with the radius of less than 10 nm, apart from the mechanical property of the nanoparticle, the surface free energy effect plays a dominant role in determining the fracture behaviors of the nanoparticle-reinforced composites. Moreover, taking the surface free energy into account, a decrease in the plastic zone size is obtained, particularly for the crack tip nearer the nanoparticle.

Microstructure and mechanical properties of Al–Si–Cu–Fe alloy-based ceramic particle-reinforced nanocomposites and microcomposites and a modified model to predict the yield strength of nanocomposites

The effects of volume fraction, size, and type of reinforcement particles on the microstructure and mechanical properties of Al–Si–Cu–(Fe) alloy matrix composites were investigated and an analytical model was modified to predict the yield strength of the particle-reinforced nanocomposites. Nano- and micro-particle-reinforced Al–Si–Cu-(Fe) matrix composites (N-AMCs and M-AMCs) were manufactured by adding two different types and sizes of reinforcement particles to Al–Si–Cu–(Fe) alloys at different volume fractions using a two-step stir casting method combined with a high-energy ball milling process and a high-pressure die-casting method. Microstructural analyzes of N-AMCs and M-AMCs were performed using SEM, EDX, and XRD. The Brinell hardness test and the tensile test were carried out to determine the mechanical properties of the N-AMCs and M-AMCs. The hardness of the N-AMCs and M-AMCs was continuously enhanced by increasing the volume fraction of the reinforcement particles, while the yield strength and ultimate tensile strength of the N-AMCs and M-AMCs were improved up to 1.5 vol.% and 4 vol.% of nano-particles and micro-particles, respectively. An analytical model was modified to predict the yield strength of N-AMCs by integrating the effective volume ratio of nano-particles into each strengthening mechanism. The results predicted by the modified model reached nearly 98% agreement with the experimental results up to 1.5 vol.% of the reinforcement particles. Nano-particles had a much greater effect on strengthening mechanisms compared to micro-particles.

Fabrication and Characterization of Aluminum Nanoparticle-Reinforced Composites.

With the expanding use of polymers in modern our lives, there is an increasing need to manufacture advanced engineering polymeric parts in a systematic and inexpensive way. Herein, we developed an organic inorganic hybrid composite material with excellent mechanical properties by enhancing the dispersion and moldability of fillers. For this, we prepared and analyzed the physical properties of acrylonitrile butadiene styrene (ABS)/aluminum nanoparticle composites. Al nanoparticles of various sizes (20 nm and 40 nm) and concentrations (3, 6, 9, and 12 wt.%) were employed. The mechanical properties of the prepared composites were measured using a universal testing machine. Rheological and thermal analyses for the composites were carried out with use of a rheometer and a differential thermal calorimeter (DSC). We also conducted optical, chemical, electrical, and morphological property studies of the samples in order to help design and produce high-performance engineering products.

Preparation of Sol-Enhanced Ni–P–Al2O3 Nanocomposite Coating by Electrodeposition

A Ni–P–(sol)Al2O3 coating was prepared on the surface of Q235 steel by direct-current electrodeposition. This method was combined with sol-gel and electrodeposition technique, instead of the traditional nanopowder dispersion, to prepare highly dispersible oxide nanoparticle-reinforced composites. The effects of temperature, pH value, and current density and Al2O3 sol on the hardness of composite coating were investigated. The coating surface morphology and structure were characterized by scanning electron microscopy and energy dispersive spectroscopy, respectively. The corrosion resistance of coatings in the presence of intermediate layers was evaluated by electrochemical measurement in 3.5% NaCl solution by open-circuit potential measurement at room temperature. The hardness and wear resistance of the coating were measured by a microindentation instrument and friction wear machine, respectively. The results showed that Al2O3 sol can effectively improve Ni–P alloy coating structure and refine grain. When the bath temperature was 55°C, the pH value was 4.5, the amount of sol was 80 mL/L, the current density was 1 A/dm2, and the hardness of the nanosol coating was 569 HV. Compared with Ni–P, the friction coefficient increases slightly, but the wear rate was only 1.768×10−6 g·m−1. The corrosion resistance was also better than that of Ni–P coating.

Interface energy effect on effective elastic moduli of spheroidal particle-reinforced nanocomposites

By incorporating the interface energy effect into a classical micromechanics framework, effective elastic moduli of a composite material containing randomly distributed nanosized prolate spheroidal inhomogeneities are investigated in this paper. The effect of interface energy, which is usually neglected in classical micromechanics theories, becomes important when the size of the reinforcement phase in the composite enters the nanometer range. The interface energy effect is simulated by inducing interface stress on the zero-thickness membrane interface between the matrix and the inhomogeneities. The interfacial stress discontinuity equations are formulated in accordance with the equilibrium conditions on the idealized interface, from which the interfacial strain discontinuity is solved. Subsequently, the effective elastic moduli are derived based on the classical micromechanics homogenization approaches. Comparisons are made of the effective moduli under the current nanomechanical framework and under classical micromechanical theory. The effective moduli are shown to be dependent upon the size of the inhomogeneities and the interface properties when the interface energy effect is considered.

A New Elastic Theory of Nanocomposites With Incoherent Interface Effect Based on Interface Energy Density

Abstract A continuum theory of elasticity based on the concept of interface free energy density is proposed to account for the effect of incoherent interfaces in nano-phase reinforced composites. With the help of the lattice model, the corresponding interface energy density is formulated in terms of the surface free energy densities of two bulk materials forming interfaces, the lattice relaxation parameters due to the spontaneous surface relaxation and lattice misfit parameters yielded by interface incoherency, while the stress jump at interfaces is formulated with an interface-induced traction as a function of interface free energy density. Compared with existing theories, the interface elastic constants difficult to determine are no longer introduced, and all the parameters involved in the present theory have definite physical meanings and can be easily determined. The coupling effects of characteristic size and interface structure in nanoparticle-reinforced composites are further analyzed with the present theory. It is found that both the decrease of nanoparticle size and the increase of interface incoherence will lead to the decrease of interface fracture toughness and increase of effective bulk and shear moduli of nanocomposites. All these results predicted by the present theory are consistent well with those obtained by previous experiments and computations, which further indicate that the present theory can effectively predict the mechanical properties of nanomaterials with complex interfaces, such as nano-phase reinforced composites and nano-scale metal multilayer composites.

Compression after Impact Behaviour and Failure Analysis of Nanosilica-Toughened Thin Epoxy/GFRP Composite Laminates.

Nanosilica particles were utilized as secondary reinforcement to enhance the strength of the epoxy resin matrix. Thin glass fibre reinforced polymer (GFRP) composite laminates of 3 ± 0.25 mm were developed with E-Glass mats of 610 GSM and LY556 epoxy resin. Nanosilica fillers were mixed with epoxy resin in the order of 0.25, 0.5, 0.75 and 1 wt% through mechanical stirring followed by an ultrasonication method. Thereafter, the damage was induced on toughened laminates through low-velocity drop weight impact tests and the induced damage was assessed through an image analysis tool. The residual compression strength of the impacted laminates was assessed through compression after impact (CAI) experiments. Laminates with nanosilica as secondary reinforcement exhibited enhanced compression strength, stiffness, and damage suppression. Results of Fourier-transform infrared spectroscopy revealed that physical toughening mechanisms enhanced the strength of the nanoparticle-reinforced composite. Failure analysis of the damaged area through scanning electron microscopy (SEM) evidenced the presence of key toughening mechanisms like damage containment through micro-cracks, enhanced fiber-matrix bonding, and load transfer.

Effect of interphase zone on the overall elastic properties of nanoparticle-reinforced polymer nanocomposites

In the current work, the effect of interphase region on the mechanical properties of polymer nanocomposites reinforced with nanoparticles is studied. For this purpose, a closed-form interphase model as a function of radial distance based on finite-size representative volume element is suggested to estimate the mechanical properties of particle-reinforced nanocomposites. The effective Young’s and shear moduli of thermoplastic polycarbonate-based nanocomposites for a wide range of sizes and volume fractions of silicon carbide nanoparticles are investigated using the proposed interphase model and molecular dynamics simulations. In order to investigate the effect of particle size, several unit cells of the same volume fraction, but with different particle radii have been considered. The micromechanics-based homogenization results are in good agreement with the results of molecular dynamics simulations for all models. This study demonstrates that the suggested micromechanical interphase model has the capacity to estimate effective mechanical properties of polymer-based nanocomposites reinforced with spherical inclusions.

Micro/Mesoporous Fe₃O₄/Fe-Phthalocyanine Microspheres and Effects of Their Surface Morphology on the Crystallization and Properties of Poly(Arylene Ether Nitrile) Composites.

The surface morphology of nanoparticles significantly affects the final properties and interfacial characteristics of their composites. Thus, investigations on the surface morphology of the nanoparticles is essential to fabricate improved nanoparticle-reinforced composites. Fe3O4/Fe-phthalocyanine (FePc) hybrid microspheres with micro/mesoporous structures were prepared via a solvothermal process and solvent etching method. The surface morphology and compositional distribution were respectively investigated using a scanning electron microscope (SEM) and a transmission electron microscope (TEM) to rule out that FePc monomers have been blended with Fe3O4 to form Fe3O4/FePc hybrid microspheres without serious agglomeration. The surface roughness of Fe3O4/FePc microspheres was investigated by the scanning probe microscope (SPM), and confirmed by the adsorption and desorption isotherms of N2. The effects of the various surface morphologies on the crystallization behavior of crystallizable poly(arylene ether nitrile) (c-PEN) were first employed to confirm the surface characteristics of the resulted microspheres. Results indicated that the etched Fe3O4/FePc microspheres would improve the crystallization degree of c-PEN, due to their much more micro/mesoporous structures than that of original Fe3O4/FePc. Then, Fe3O4/FePc hybrid microspheres reinforced PEN composite films were prepared and their interfacial compatibility was monitored using an SEM. Excellent thermal stability and improved mechanical properties were obtained by combining the etched Fe3O4/FePc and PEN matrix. The excellent surface properties and micro/mesoporous structures make the novel Fe3O4/FePc an excellent candidate of organic/inorganic hybrid fillers and micro/mesoporous materials.

Rotational moulding and mechanical characterisation of halloysite reinforced polyethylenes

Extensive experiments with rotationally moulded polyethylene halloysite nanocomposites have been conducted. Previous studies regarding the use of filler materials in rotational moulding often report problems with agglomerations or inward migration of the filler. Despite the previous advances in machine adaptations and mould configurations to apply internal pressure, this study has focused mainly on non-pressurized composite production. Halloysite is a natural, nano-size, mineral clay with different reactivities from the internal aluminol and external siloxane surfaces. Due to its morphology and chemical nature, halloysite is easier to process compared to other fillers and achieves good particle dispersion, making it a potential candidate for reinforcing rotationally moulded products. In this study, nanoparticle-reinforced composites containing halloysite with medium density or high density polyethylene were produced by rotational moulding. The influence of halloysite on the melt flow index and mechanical performance, tensile, flexural and impact properties, were investigated.

A micromechanical study on the existence of the interphase layer in particle-reinforced nanocomposites

In this paper, the effective elastic properties of nanoparticles reinforced nanocomposites including effects of an interphase layer around the nanoparticles are determined using analytical micromechanical approach. The present micromechanical model is based on the Green’s function and the interface operator. By using the interface operator, the interphase layer and the nanoparticle are combined as a single spherical inclusion and then the effective properties of the composite are calculated by using the Green’s function. To assess the presented method, epoxy-silica nanocomposites are thoroughly studied in this paper. Since there is no direct method to determine physical and mechanical properties of the interphase layer, we have presented a method to determine these properties, namely volume fraction and elastic modulus of the interphase layer, for epoxy-silica nanocomposites by correlating the experimental data for effective elastic properties of the epoxy-silica nanocomposites and those obtained by the presented model. Applying the presented method to various experimental data available in the literature, epoxy-silica nanocomposites are characterized into nanocomposites with, and without an interphase layer. The presence or absence of the interphase layer is concluded by the value of its volume fraction determined by the present method. It is observed that nanocomposites with surface-modified silica nanoparticles yield perfect bonding with the matrix and do not form an interphase layer. On the other hand, nanocomposites with raw silica nanoparticles (without surface modification) yield an interphase layer between the nanoparticles and the matrix which is softer than the matrix.

Closed-form formulas for the effective properties of random particulate nanocomposites with complete Gurtin–Murdoch model of material surfaces

The objective of this work is to present an approach allowing for inclusion of the complete Gurtin–Murdoch material surface equations in methods leading to closed-form formulas defining effective properties of particle-reinforced nanocomposites. Considering that all previous developments of the closed-form formulas for effective properties employ only some parts of the Gurtin–Murdoch model, its complete inclusion constitutes the main focus of this work. To this end, the recently introduced new notion of the energy-equivalent inhomogeneity is generalized to precisely include all terms of the model. The crucial aspect of that generalization is the identification of the energy associated with the last term of the Gurtin–Murdoch equation, i.e., with the surface gradient of displacements. With the help of that definition, the real nanoparticle and its surface possessing its own distinct elastic properties and residual stresses are replaced by an energy-equivalent inhomogeneity with properties incorporating all surface effects. Such equivalent inhomogeneity can then be used in combination with any existing homogenization method. In this work, the method of conditional moments is used to analyze composites with randomly dispersed spherical nanoparticles. Closed-form expressions for effective moduli are derived for both bulk and shear moduli. As numerical examples, nanoporous aluminum is investigated. The normalized bulk and shear moduli of nanoporous aluminum as a function of residual stresses are analyzed and evaluated in the context of other theoretical predictions.

High Temperature Wear Behaviour of Nano/Micro B4C Reinforced Aluminium Matrix Composites Fabricated by an Ultrasonic Cavitation-Assisted Solidification Process

The micro- and nano-composites containing 2, 4 and 6 by wt% of B4C particles in aluminium are fabricated using stir and ultrasonic cavitation-assisted casting processes. The fabricated composites are characterized by using scanning electron microscopy, X-ray diffractometer. The dry sliding wear behaviour of the prepared composites are investigated by using pin on disc method at an applied load of 4, 8, 12, 16 N for pin temperatures of 100 and 200 °C. The wear study at room temperature is also carried out for comparison. The investigations indicate that the wear resistance of the nano particle-reinforced composites are better than those of the micro B4C particle-reinforced composites under all loads and different temperatures. Analysis of wear surface and debris by scanning electron microscopy with energy dispersive X-ray diffractometer reveals the nature of wear mode of samples. It is also observed that the predominant wear mechanism for pure aluminium at 100 and 200 °C are adhesion and metal flow respectively, whereas for fabricated composites abrasion, delamination and oxidation are the most dominant wear mechanisms.

The effect of deformation on wear behaviour of Al-5% red mud particle reinforced nano composites synthesised by stir casting

The micro-sized redmud particles have been modified to nano structured red mud using high energy ball milling. Composites were fabricated by stir casting and experiments were conducted under laboratory condition to assess the wear characteristics of Al-5 wt% red mud (micro-sized) and Al-5 wt% red mud (nano-structured) composites on pin-on-disc wear testing machine. The hardness of the composites with coarse grained red mud particle reinforcement was significantly increased with increase in deformation under compression. The hardness of the composites with nano structured red mud particle reinforcement was not increased due to strain softening occurred under compression. The wear rate was decreased with deformation and for deformations beyond 30%, the wear rate was increased due to strain softening. The increased frictional thrust at higher load results in increased debonding and caused easy removal of material and hence the wear rate is increased with increase in normal load.