Hybrid Nanocomposite Samples Research Articles

Determination of nano-graphene content for improved mechanical and tribological performance of Zn-based alloy matrix hybrid nanocomposites

The primary objective of this study is to explore the fabrication of a hybrid nanocomposite (HNC) composed of ZnAl40Cu2 alloy, graphene, and B4C particles, while also determining the optimal graphene reinforcement ratio for enhanced properties. Our methodology entails the production of HNC powders (HNPs) through mechanical milling, where we combine graphene nanoplatelets with B4C microparticles into ZnAl40Cu2 alloy powders. Throughout this process, we maintain a constant B4C content of 1.5 wt%, while varying the graphene content at 1.5 wt%, 3 wt%, and 4.5 wt%. Following the characterization of all produced powders, which includes an assessment of powder morphology, powder size distribution, and powder microhardness, we proceed to hot-press the HNPs to create bulk HNC samples. After consolidating the specimens, a comprehensive series of tests are carried out to determine microstructural, mechanical (hardness and tensile strength) and tribological properties. Our results reveal that the HNC specimen with graphene content of 3 wt% (referred to as A2) displays the most notable enhancements in properties. Specifically, A2 exhibits an impressive hardness of 163 HB, surpassing the hardness of the ZnAl40Cu2 matrix alloy, which measures at 133 HB. Furthermore, its ultimate tensile strength significantly outperforms the ZnAl40Cu2 matrix alloy, with a remarkable value of 223 MPa compared to 157 MPa. However, it is worth noting that the improvement in wear resistance for HNCs is most pronounced up to a certain threshold of graphene content, which is 3 wt%.

Influence of graphene nanoplates and titanium diboride particulate on wear and interfacial bonding properties of sintered aluminium alloy composites

Graphene has been considered an appropriate reinforcing filler for aluminium/titanium metal matrix composites due to its outstanding strength and stiffness and its exceptional thermal and electrical properties. The variable concentrations of graphene nanoplates (GNPs) was considered in this research, such as 2 %, 4 %, 6 % and 8 %, for determining wear properties and interface bonding aluminium alloy composites. The graphene-reinforced Al 7075/10 % TiB2 hybrid nanocomposite samples were produced using ball milling and pressure-less vacuum sintering process. The wear loss was investigated for all the variable graphene concentration samples with respect to wear load and sliding distance by pin-on-disk method and optimum concentatrion of GNPs was obtained by design of experimental (DOE) analysis. Further, Field Emission Scanning Electron Microscopy (FESEM), Elemental mapping, Energy Dispersive X-ray (EDX), and microhardness tests were utilized to analyze the graphene-reinforced Al 7075/10 % TiB2 hybrid nanocomposites, It was concluded that the wear resistance and microhardness of Al/10 % TiB2/4 % GNPs increased by 71.3 % and 17.6 %, respectively, compared with non-hybrid aluminium alloy materials. Moreover, a Transmission Electron Microscope (TEM) has been used to investigate the interfacial strength of aluminium alloy composites. The wear loss characteristics was also optimized using and central composite design (CCD) of response surface methodology (RSM).

A Study on the Optimization of Nano-B4C Content for the Best Wear and Corrosion Properties of the Al-Based Hybrid Nanocomposites

This investigation is dedicated to producing hybrid nanocomposites based on AA2024, achieved through the utilization of powder metallurgy methods encompassing mechanical milling and hot pressing. The research focused on studying how changes in B4C content influence the mechanical, wear, and corrosion behavior of AA2024/h-BN/B4C hybrid nanocomposites. The findings revealed that as the B4C content increased, the relative density values decreased, and higher porosity values were observed in the hybrid nanocomposite samples. Among the tested samples, the hybrid nanocomposite with 4 wt% B4C exhibited the most favorable properties. It demonstrated significantly higher hardness and ultimate tensile strength compared to AA2024 matrix alloy, with values of 161 HB and 372 MPa, respectively. In contrast, the matrix alloy showed hardness and ultimate tensile strength values of 105 HB and 237 MPa, respectively. Furthermore, the wear resistance of hybrid nanocomposite with 4 wt% B4C displayed approximately 14 times greater wear resistance under 40 N load compared to the unreinforced AA2024 matrix alloy. The corrosion test results have revealed that the corrosion resistance of the hybrid nanocomposite reinforced with 4wt% B4C is nearly 47% higher compared to the corrosion resistance of the unreinforced AA2024 alloy. This nanocomposite exhibits the highest polarization resistance of 5.21 Ω.cm2.

INFLUENCE OF MECHANICAL AND THE CORROSION CHARACTERISTICS ON THE SURFACE OF MAGNESIUM HYBRID NANOCOMPOSITES REINFORCED WITH HAp AND rGO AS BIODEGRADABLE IMPLANTS

Magnesium composites stay relevant for the applications of biodegradable implant as they are harmless and possess characteristics such as density and elastic modulus analogous to the cortical bone in humans. But corrosion is one major issue associated with magnesium when the biomedical applications are contemplated. Moreover, load bearing abilities are also required in case of an orthopedic implant. In this study, to achieve the desired implant characteristics, hybrid nanocomposites (HNCs) of Mg–2.5Zn binary alloys such as metal matrix, hydroxyapatite (HAp), and reduced graphene oxide (rGO) as reinforcements were fabricated via the vacuum-assisted stir casting method. The overall weight percentage of the reinforcements was fixed at 3% and both the reinforcements varied in compositions by weight to prepare the samples S0 (Pure Magnesium), S1 (Mg–2.5Zn–0.5HAp–2.5rGO), S2 (Mg–2.5Zn–1.0HAp–2.0rGO), S3 (Mg–2.5Zn–1.5HAp–1.5rGO), S4 (Mg–2.5Zn–2.0HAp–1.0rGO), and S5 (Mg–2.5Zn–2.5HAp–0.5rGO), respectively. The influence of mechanical characteristics such as tensile strength, compressive strength, and microhardness as well as the corrosion over the surface of the nanocomposite in simulated body fluid (SBF) have been assessed for their suitability as biodegradable orthopedic implants. Results suggest that the fabricated nanocomposites exhibit superior characteristics in comparison to pure magnesium. Increasing the HAp from 0.5 wt.% to 2.5 wt.% enhanced the compressive strength and reduced the corrosion rate. On the other hand, increasing the rGO from 0.5 wt.% to 1.5 wt.% increased the tensile strength. The formation of apatite layer over the composites is observed in the SBF solution. Among all the fabricated hybrid nanocomposite samples, the sample S3 (Mg–2.5Zn–1.5HAp–1.5rGO) with equal wt.% of HAp and rGO exhibited 209.60 MPa of ultimate tensile strength, 300.1 MPa of ultimate compressive strength, and a corrosion rate of 0.91 mm/year thus making it the best suited and a prospective material for biodegradable implant application.

A study on the improvement of wear and corrosion properties of ZA40/Graphene/B4C hybrid nanocomposites

The objective of the study was to investigate the production and evaluation of ZA40/Graphene/B4C hybrid nanocomposite (HNC). To fabricate the HNC powders (HNPs) involved the combination of graphene nanoplatelets and B4C micro-particles with ZA40 powders through mechanical milling. The graphene content remained constant 1 wt%, while the B4C content varied at 1 wt%, 2 wt%, and 3 wt%. After an 8-hour milling process, the HNPs were subjected to hot-pressing to create bulk HNC samples. Various tests, including microstructural analysis, hardness, tensile strength, wear resistance, and corrosion resistance, were conducted on the consolidated samples. The results indicated that the HNC sample containing 3 wt% B4C (S3) exhibited the most favorable properties. This sample displayed a hardness value of 181 HB, significantly higher than the ZA40 matrix alloy's hardness of 133 HB. Moreover, its ultimate tensile strength measured at 243 MPa, which was much higher than the ZA40 matrix alloy (157 MPa). The wear resistance of HNCs increased significantly with an increase in B4C content. The sample containing 3 wt% B4C demonstrated approximately 3.5 times greater corrosion resistance than the unreinforced ZA40 matrix alloy.

Machinability Study on AA6061/2 SiC / Graphite Hybrid Nanocomposites Fabricated through Ultrasonic Assisted Stir Casting

Aluminium-based hybrid metal matrix nanocomposites (AA-HMNCs) have numerous applications due to their higher strength-to-weight ratio and good mechanical and tribological properties. However, the machinability aspect of these materials must be carefully explored before employing them in various engineering applications. The present study involves the fabrication of AA6061/2 wt.% SiC/x wt.% graphite (x= 1, 2, 3) hybrid nanocomposites and subsequently subjecting them to machinability investigation. All the hybrid nanocomposite samples are fabricated through ultrasonic assisted stir casting technique. The effect of machining parameters and graphite content of the sample on cutting force and surface roughness is discussed based on experimental data. Experiments are performed based on the central composite design of response surface methodology, and the corresponding output responses are recorded. ANOVA analysis revealed that the graphite content has the highest authority over surface roughness and cutting force. High cutting speeds accompanied by low feed and depth of cut have resulted in reduced cutting forces and better surface finish. Chip morphology studies have also subsequently indicated better machinability with increased graphite content.

Optimization and effect of B4C/Al2O3 with graphite particulates on tribological properties of Al7075 surface hybrid nanocomposite

Aluminium alloy surface hybrid nanocomposite, reinforced with boron carbide (B4C), aluminium oxide (Al2O3), and Graphite (Gr) at different combination mixtures by weight ratio have been fabricated on Al7075-T6 aluminium plate by employing friction stir processing (FSP). The mixtures of definite proportions were packed in an array of blind holes 2.5 mm in diameter and 3 mm deep which are 6 mm apart from each other. FSP was done with processing factors of 750 rpm revolving speed, 20 mm min−1 feed, and tool angle of 3°. The prepared hybrid composites were sectioned for microstructure, macrostructure, wear, and hardness evaluation. In the metal matrix surface composite, the scanning electron microscope (SEM) and field emission scanning electron microscope (FESEM) depict the homogeneity in the distribution of reinforcement elements, microstructure, and wear behaviour. Under dry sliding conditions, the nanocomposite’s wear behaviour was investigated by adopting a central composite design (CCD) at 3 levels in response surface methodology (RSM) for optimization. The wear characteristics are analyzed using pin on disc apparatus. The wear property of the nanocomposites with distinct reinforcement ratios was evaluated. Higher hardness values (maximum of 191 Hv) were found in hybrid nanocomposite samples than in the plain FSPed samples (149Hv) without reinforcement. It is evident, that the wear loss depends on the relative weight ratio of B4C and Al2O3 with a constant amount of graphite and the minimum wear loss of 2.9421 mm3 is obtained from composite with 30 B4C + 60 Al2O3+10 Gr reinforcement ratio than the wear loss of 8.2292 mm3 obtained from plain FSPed composite. The optimal combination of parameters, Al2O3 60%, load 20 N, and velocity 1 m s−1 was identified from RSM. The hybrid nanocomposite having a reinforcement mixture of 30 B4C + 60 Al2O3 + 10 Gr exhibits a significant wear resistance than other combination ratios. This is endorsed by the enhancement in binding strength of the matrix and the pinning effect of hard reinforcements, which act against the applied shear force.

Microstructural Analysis and Mechanical Properties of a Hybrid Al/Fe2O3/Ag Nano-Composite

This work aims to define the microstructure and to study the mechanical properties of an Al matrix incorporated with various amounts of Fe2O3 (3, 6, 9, 12 and 15 wt.%) with a constant amount of Ag at 1 wt.%. Al/Fe2O3 + Ag hybrid nano-composite samples are manufactured using powder metallurgy. An aluminum matrix is considered an important alloy, owing to its properties such as being lightweight, strong and corrosion and wear resistant, which enable it to be used in many applications, such as electronics, aerospace and automotive purposes. Various examinations have been performed for the samples of this work, such as Field Emission Scanning Electron Microscopy (FESEM) and X-ray Diffraction (XRD) analysis to estimate the microstructure and phases of manufactured nano-composites. Mechanical testing is also carried out, such as micro-hardness testing, compressive testing and wear testing, to estimate the mechanical properties of the hybrid nano-composites. The results of FESEM and XRD demonstrate that Fe2O3 and Ag nanoparticles are uniformly distributed and dispersed into the Al matrix, whereas the mechanical tests show that enhancement t micro-hardness, compressive strength of 12 wt.% Fe2O3 + 1Ag and wear rate decrease to a minimum value of 12 wt.% of Fe2O3 + 1Ag.

Synthesis of AA8050/B4C/TiB2 Hybrid Nanocomposites and Evaluation of Computer‐Aided Machining Parameters

This research focusses on synthesizing the hybrid nanocomposite samples with AA8050 and the reinforcement of B4C and TiB2 nanoparticles at 3 different quality grades. To investigate their machinabilities on the prepared composites in the computer‐aided machining centre, the objectives are maximizing the material removal rate (MRR) and minimizing the surface roughness for a specific application. Stir casting process was employed in synthesizing the hybrid nanocomposite samples. Utilizing CNC turning centre was employed to investigate machinability performance on hybrid nanocomposite samples. The PVD‐coated HSS tool and dry cutting environment were considered. The quality of machining was investigated by observing the surface roughness on the machined surfaces of samples of hybrid nanocomposite. The machining rate was investigated through the response of material removal rate at as per Taguchi design of experiments L27 orthogonal array. The hybrid nanocomposite synthesizing parameter of contribution of nanoparticle reinforcement (8%, 10%, and 12%) and the Turing parameters include spindle speed (800 rpm, 1000 rpm, and 1200 rpm), machining feed (0.05 mm/rev, 0.10 mm/rev, and 0.15 mm/rev) and depth of cut (0.5 mm, 0.75 mm, and 1 mm). The best performing input levels were identified through Taguchi analysis and the involved input variables were analysed and prediction model developed through ANOVA. The maximum material removal rate and the minimum surface roughness were reordered as 1380 mm3/min.

Experimental investigation of machinability in laser-assisted machining of aluminum-based nanocomposites

In recent years, the application of aluminum-based hybrid nanocomposites has been developed in industries like automotive and aerospace due to their remarkable properties. Hence, the machinability investigation of these materials is essential. In this research, laser-assisted machining was performed on aluminum based hybrid nanocomposite samples fabricated by the electromagnetic stir casting method. Continuously, the effects of process parameters namely laser power, depth of cut and cutting speed on the surface roughness, cutting force and temperature were assessed by Design of Experiments (DOE) technique. Taguchi standard orthogonal method (L9 (33)) was used to analyze the process factors. Based on the results, depth of cut had no effect on the surface temperature. Moreover, cutting speed and depth of cut exhibited the major influence on the surface roughness and cutting force, respectively. The optimal cutting conditions were obtained for surface roughness at laser power of 450 W, cutting speed of 30 m/min, and cutting depth of 0.2 mm and were obtained for cutting force at laser power of 450 W, cutting speed of 30 m/min, and cutting depth of 0.1 mm.

Development of non-stoichiometric hybrid Co3S4/Co0.85Se nanocomposites for an evaluation of synergistic effect on the OER performance

Water electrolysis powered by renewable energy sources to produce green hydrogen is a very promising and sustainable alternative to fossil fuels, as well as one of the best approaches for significantly reducing carbon footprints and controlling pollution. In this study, novel hybrid non-stoichiometric nanocomposite Co3S4/Co0.85Se electrocatalyst materials were synthesized using a simple and one-pot eco-friendly hydrothermal method. The as-prepared samples were characterized using X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) for structural features. Crystalline phases of Co3S4, Co0.85Se, and mixed phases in the hybrid samples were confirmed through XRD. Uniformly distributed agglomerated nanoparticles (30-80 nm) of Co3S4, clearly distinguishable nanoaggregates (20-90 nm) of Co0.85Se, and nanoflakes covered with nanoparticles (30-150 nm) of Co3S4/Co0.85Se were confirmed by FESEM. The synergistic effects of the hybrid nanocomposite due to the combination of Co3S4 (containing two different oxidation states of cobalt) and non-stoichiometric Co0.85Se, was investigated towards the oxygen evolution reaction (OER). The electrocatalytic studies confirmed that the Co3S4/Co0.85Se electrocatalyst exhibited a low overpotential of 362 mV @ +30 mA.cm−2 towards the OER in an alkaline solution in comparison with Co3S4 and Co0.85Se electrocatalysts. Furthermore, a low overpotential of 1.59 V at a high current density and a high electrochemical active surface area (ECSA) of 210 cm2 was achieved due to the combined effects of chemical coupling between the Co3S4 and Co0.85Se. Chronoamperometric studies revealed excellent stability of the hybrid nanocomposite samples with negligible changes in the overpotential, even after 30 hours of testing. The synergetic effect of cobalt chalcogenides due to the nanoscale interaction was confirmed by the enhanced electrocatalytic activity.

Determination of mechanical properties of two-phase and hybrid nanocomposites: experimental determination and multiscale modeling

Abstract In this paper, the effects of filler content and the use of hybrid nanofillers on agglomeration and nanocomposite mechanical properties such as elastic moduli, ultimate strength and elongation to failure are investigated experimentally. In addition, thermoset epoxy-based two-phase and hybrid nanocomposites are simulated using multiscale modeling techniques. First, molecular dynamics simulation is carried out at nanoscale considering the interphase. Next, finite element method and micromechanical modeling are used for micro and macro scale modeling of nanocomposites. Nanocomposite samples containing carbon nanotubes, graphene nanoplatelets, and hybrid nanofillers with different filler contents are prepared and are tested. Also, field emission scanning electron microscopy is used to take micrographs from samples’ fracture surfaces. The results indicate that in two-phase nanocomposites, elastic modulus and ultimate strength increase while nanocomposite elongation to failure decreases with reinforcement weight fraction. In addition, nanofiller agglomeration occurred at high nanofiller contents especially higher than 0.75 wt% in the two-phase nanocomposites. Nanofiller agglomeration was observed to be much lower in the hybrid nanocomposite samples. Therefore, using hybrid nanofillers delays/prevents agglomeration and improves mechanical properties of nanocomposite at the same total filler content.

Friction and wear reduction by graphene nano platelets for hybrid nano Aluminium matrix composite under dry sliding conditions

Friction losses and wear losses are the main failure reasons in the internal combustion (IC) engine components i.e., cylinder liner and piston. So, it demands lightweight self-lubricating low friction and wear-resistant materials to increase the efficiency and reduce the emission issue of the IC engine. In this concern, tribological tests are performed on self-lubricating aluminium composites samples reinforced with 6 wt.% of γ-Al2O3 and Graphene Nano Platelets (GNP) with varying concentration (0.5 wt.% - 5 wt.%), using ball-on-disc tribo-configuration under dry sliding conditions. The scope of this study is to investigate the anti-friction and anti-wear properties of GNP as reinforcement in the hybrid nanocomposite. The hybrid nanocomposite samples are fabricated using Spark Plasma Sintering (SPS) fabrication route. From the results, it is reported that friction and wear reduction percentage is 37.43 % and 51.64 %, respectively for the hybrid nanocomposite with 5 wt. % GNP. It is attributed to the inclusion of GNP, which reduces the Coefficient of Friction (COF) and improves wear resistance of the composite significantly.

CORROSION AND WEAR PERFORMANCE OF ZA27/GRAPHENE/B4C HYBRID NANOCOMPOSITES PRODUCED BY POWDER METALLURGY

In this research paper, dry sliding (unlubricated), corrosion and abrasive wear behavior of ZA27/ Graphene/ B4C hybrid nanocomposites were studied. The hybrid nanocomposite samples were fabricated by powder metallurgy technique. Tribological tests were performed by employing a ball-on-disc type in the unlubricated situation and different loads (1, 2, 5 and 10 N). The examination of the worn and corroded surfaces, the powder characterization was performed using scanning electron microscopy (SEM). The findings indicated that the increase in B4C nano-particle content can positively effect on the corrosion and wear behavior of the hybrid nanocomposites. The electrochemical polarization measurements showed that increasing of the nano B4C content causes high corrosion resistance in the hybrid nanocomposites. The corrosion tests showed that the corrosion rate value of the ZA27/Graphene/B4C hybrid nanocomposites decreased from 59.02 mpy to 16.77 mpy with increasing the nano B4C content from 0.25% to 2%.

Novel ZA27/B4C/Graphite Hybrid Nanocomposite-Bearing Materials with Enhanced Wear and Corrosion Resistance

In this study, nanosized B4C and graphite-reinforced ZA27 matrix hybrid nanocomposites were produced with mechanical milling followed by hot pressing. The friction coefficient values of nanocomposite samples remarkably decreased from 0.5036 (± 0.085) to 0.2575 (± 0.021) with the increase of milling time to 24 hours for nanocomposite powders. That was almost two times lower than those of unmilled nanocomposites. It was determined that the good distribution of reinforcement particles in the microstructure and low grain size allowed the formation of a protective oxide layer against corrosion. The corrosion resistance of the nanocomposite materials obtained from nanocomposite powders milled for 24 hours was quite superior to the others. The results revealed that the corrosion rate values were 29.068 and 4.033 mpy for hybrid nanocomposite samples produced from unmilled and milled powders for 24 hours, respectively.

Effect of nanoparticles on surface characteristics of dental nanocomposite

AbstractThe main purpose of this study is to present a systematically assessment of wear characteristics of hybrid dental composites. Lanthanum oxide (La2O3) nanofillers are an imperative part of fillers in hybrid dental composites to increase their cosmetic features and radiopacity that are added as a second filler along with quartz microfillers. In this research, hybrid nanocomposite samples are synthesized by different content of La2O3 nanofillers to study their effect on surface behaviour, friction coefficient and wear resistance that further discussed using scanning electron microscopy (SEM) images of the wear track and debris. The results provide a significant influence of nanofillers on wear resistance with samples having higher nanofillers showing lower wear resistance; however, coefficient of friction reaches an optimum and increase with higher content. The wear behaviour is also related to micro‐hardness of specimens to find a detailed understanding of wear mechanism.

Synthesis, Characterization, and Improvement of Supercapacitor Properties of NiMoO4 Nanocrystals with Polyaniline

In the present work, bare nickel molybdate (NiMoO4) and polyaniline enfolded nickel molybdate (NiMoO4/PANI) nanocomposite hybrid electrode materials were prepared by sonochemical and in situ oxidative polymerization techniques, respectively. The phase formation, microstructure and surface morphology of all the freshly prepared bare and hybrid nanocomposite samples were analyzed by X-ray diffraction (XRD), Fourier transform infrared (FTIR), confocal Raman spectroscopy, High-resolution transmission electron microscopy (HR-TEM) and Atomic force microscopy (AFM) studies, respectively. XRD characterization confirmed that the polyaniline polymer does not hinder the crystallization of the NiMoO4 nanocrystals. Fourier transform infrared spectra and confocal Raman spectra were indicating that the NiMoO4/PANI nanocomposite was successfully prepared. The electrochemical performances of bare NiMoO4 nanocrystals and NiMoO4/polyaniline nanocomposite electrodes were investigated through cyclic voltammetry (CV), chronopotentiometry (CP) and cyclic stability studies. The observed results demonstrated that the newly prepared NiMoO4/polyaniline nanocomposite electrode exhibits higher specific capacitance of 285 Fg−1 and good cyclic stability of 92% retention even after 500 cycles than that of bare NiMoO4 nanocrystals. Thus, the NiMoO4/PANI nanocomposite could be a promising electrode for supercapacitor applications.

Elastic behaviour of hybrid cross-linked epoxy-based nanocomposite reinforced with GNP and CNT: experimental and multiscale modelling

Experimental method and multiscale modelling based on molecular dynamics simulation have been used to determine mechanical properties of carbon nanotube and graphene nanoplatelet hybrid nanocomposites. Samples containing two different mix ratios of hybrid nanofillers were subjected to tensile loading. Also, micrographs were obtained from samples fracture surfaces using field emission scanning electron microscope and SEM. These images showed that nanofillers were well dispersed in the matrix. In multiscale modelling, a new method has been developed to estimate the Young’s moduli of hybrid nanocomposite samples. To this end, atomistic modelling has been employed to investigate the mechanical properties of molecular samples at nanoscale level. In this step, epoxy cross-linked atomic models have been constructed utilizing molecular dynamics. Next, micromechanical modelling was used to bridge elastic constants of molecular samples from nanoscale to microscale. Also, the calculated Young’s moduli of the hybrid nanocomposite samples obtained from multiscale modelling were compared with experimental measurements and differences less than 7% were observed. Finally, the effects of effective fibre aspect ratio on elastic modulus of hybrid nanocomposite were investigated using the multiscale method. The results indicated an increase in hybrid nanocomposite Young’s modulus with effective fibre aspect ratio. In summary, this paper presents a new method for calculating the hybrid polymer-based nanocomposite properties using a multiscale method.

Effect of Hybridization of Carboxyl‐Terminated Acrylonitrile Butadiene Liquid Rubber and Alumina Nanoparticles on the Fracture Toughness of Epoxy Nanocomposites

The aim of this work was to study the effect of carboxyl‐terminated acrylonitrile butadiene (CTBN) liquid rubber and alumina nanoparticles (Al2O3) on the fracture toughness of an epoxy resin. Hybrid nanocomposite samples were prepared by the inclusion of the optimum concentration of CTBN (15 phr) and 0–10 phr Al2O3 into the epoxy matrix. Samples were examined using Fourier transform infrared spectroscopy, scanning electron microscopy, and fracture toughness test. Fractal dimension values were also estimated from the edge of the fracture surfaces for the hybrid samples. The maximum value of critical stress intensity factor, K IC, was found for the non‐hybrid sample containing 15 phr CTBN and the G IC values showed an increasing trend as it was expected from the increase in K IC values and decrease in Young's modulus. The maximum K IC for the hybrid samples was obtained for the one containing 7 phr Al2O3 and an almost similar trend was observed for G IC, accompanied with the significant changes in the fracture surface morphology. These were consistent with the fractal dimension results, where the sample containing 7 phr Al2O3 exhibited the maximum roughness. Therefore, the hybrid system of epoxy/CTBN (15 phr)/Al2O3 (7 phr) was found to be the optimum formulation. POLYM. COMPOS., 40:2700–2711, 2019. © 2018 Society of Plastics Engineers

Impact resistance of hybrid glass fiber reinforced epoxy/nanoclay composite

The effect of nanoclay addition in Glass Fiber Reinforced Epoxy (GFRE) composites on impact response was studied. The epoxy nanocomposite matrix with 1.5 and 3.0 wt% loading of I.30E nanoclay was produced by high shear mixing. Hybrid GFRE nanoclay composite plates were manufactured by hand layup and hot pressing techniques using electrical grade-corrosion resistant (E-CR) glass fiber mats. The laminates were then subjected to low-velocity impact with energies between 10 and 50 J. Addition of nanoclay was found to improve peak load and stiffness of GFRE. Nanoclay loading of 1.5 wt% resulted in optimum properties, with 23% improvement in peak load and 11% increase in stiffness. A significant reduction in physical damage was also observed for hybrid nanocomposite samples as compared to GFRE. This was mainly attributed to transition in damage mechanism due to nanoclay addition. Clay agglomeration in samples with 3.0 wt% loading contributed towards limiting the improvement in impact resistance.