Hybrid Composite Samples Research Articles

Influence of different carbon allotrope filler on the VOC sensitivity of polymer composite

In this work, both, pristine and hybrid polyisoprene as well as ethylene vinyl acetate copolymer nanocomposites with carbon nanoparticles and carbon nanotubes were developed and studied for their application in toluene sensors. The response to toluene was determined for pristine and hybrid composite samples. Hybrid samples were compared to pristine composite samples and the composite with highest sensing effect is obtained.

Mechanical Properties of Hybrid Polymer Composite Using Natural Fiber and Nanoparticle

Hybrid polymer composite were prepared by incorporating two indigenous agro-industrial waste reinforcements, sugarcane bagasse fiber (SBF) and coconut coir fiber (CCF) into epoxy resin through the hand lay-up technique. Nano-silica was also added to enhance the mechanical performance of composite materials. The alkaline treatment on the surface of natural fibers was carried out and its effects on the mechanical properties were investigated. Generally, it is found that the CCF reinforced epoxy composites exhibited higher mechanical properties as compared to the SBF reinforced epoxy composites. For hybrid composite samples, (2.5wt%SBF+12.5wt%CCF) had attained the highest mechanical performance amongst all other different ratio percentage of hybrid polymer composite.

Effect of mercerization on the mechanical and thermal response of hybrid bagasse fiber/CaCO3 reinforced polypropylene composites

This study evaluated the effect of sodium hydroxide mercerized bagasse fiber (BF) on the mechanical and thermal properties of polypropylene composites reinforced with hybrid BF/calcium carbonate (CaCO3). Samples were fabricated with a compression molding machine and characterized for tensile, flexural, and thermal properties. Hybrid composites with mercerized BF (HMC) exhibited improved mechanical properties than the unmercerized hybrid composite (UHC), single-component composite (SC) and control sample. Additionally, TGA/DTG analysis revealed that the HMC were more thermally stable in comparison with other samples. Crystallinity index of HMC was about 24% higher than UHC, as indicated by XRD analysis. SEM images showed good interfacial adhesion in the morphology of HMC compared to UHC, which contributed to the improved thermal and mechanical properties exhibited by HMC. These results indicated that mercerization treatment and reinforcement hybridization could be utilized for improving the thermal and mechanical responses of natural fiber reinforced polypropylene composites.

Effect of Volume Fraction of Reinforcement Layers on the Mechanical Properties of S-glass-Carbon-Epoxy Hybrid Composites

Abstract In the present study hybrid composites having various ratios of S-glass and high modulus Carbon fibres namely 100% S-glass(S-1), 80% S-glass with 20% Carbon(S-2), 60%-S-glass with 40% Carbon(S-3), 35% S-glass(S-4) with 65% Carbon, and 100% Carbon(S-5) with 0% S-glass were fabricated. Tensile strength, tensile modulus, flexural strength of these composites were measured. For samples S-2,S-3,S-4 modulus on both the faces (Carbon and S-glass side) were measured in a single tensile test to understand variation in elongation of Carbon and S-glass side of a hybrid composite as a function of applied load. Resultant tensile strength and modulus were compared with the predicted values using rule of mixtures. When either of reinforcements namely S-glass or Carbon is in lower proportion as compared to the other (S-2, S-4), the lower proportion reinforcement is behaving like the higher proportion reinforcement, in terms of its elongation showing the hybrid effect. When both reinforcements are in approximately equal proportions (S-3), then they are behaving like independent systems and thus showing significant deviation from predicted modulus. It is found that, as the high modulus Carbon fabric content was increased, there is a significant improvement in the modulus of the composite. However, the strength values were found to come down. Flexural strength of each of the hybrid composites was measured by applying bending load on sample from Carbon side as well as S-glass side separately. For the same composition of hybrid composite samples, when sample was loaded from Carbon side flexural strength was found to be 22.5% more strength as compared to the flexural strength when it was loaded from S-glass side. Reasons for the same were analysed using failure modes of composites and also from fracture toughness (K1C) of pure S-glass-epoxy (S-1) and pure Carbon-epoxy composite (S-5).With the help of opto digital microscope fracture morphologies were analysed and the reasons for the observed results trends were proposed.

Influence of Water Ageing on Mechanical Properties of CaCO<sub>3</sub> Filler Filled Epoxy Resin and <em>Sansevieria</em>/Carbon Fiber Reinforced Composites

The present paper studies water absorption behavior and its consequence on mechanical properties of untreated and chemically treated Sansevieria /carbon fiber reinforced hybrid epoxy (Sria/CF-Ep) composite with calcium carbonate (CaCO3) nanoparticles. Sansevieria /carbon fiber (30/5 wt%) reinforced hybrid epoxy composite with 1.5, 3 and 4.5 wt% of CaCO3 have been developed by hand lay-up method followed by heat press. The water absorption characteristics of the Sria fibers were obtained by immersing the composite samples in sea water at room temperature, until reaching their water content saturation level. The dry and water-immersed hybrid composite samples were subjected to hardness, interlaminar shear, tensile, flexural, and impact tests. The water absorption development of hybrid composites was found to follow Fickian diffusion behavior. Diffusion coefficients and maximum water uptake results were evaluated; the outcome showed that both increased with an increase in filler loading to study the consequence of water penetration in the fiber/matrix interface. The study shows that the mechanical and water-resistant properties of the Sria were improved through chemical treatment and hybridization. Nevertheless, as a result of water penetrating the fiber/matrix interface, longer water-immersion times reduced the tensile and flexural strength of the composites.

Spectrometric analysis of intentionally stained hybrid and nanohybrid composites – An In vitro study

Background: This study aims to investigate the effects of different staining solutions on the color stability of hybrid composites and nanohybrid composites. Materials and Methods: One hundred and ten composite resin samples were made in disc shape and divided into two groups, comprising 55 samples each of hybrid composite samples and nanohybrid composite samples. Both the groups were further divided into experimental group of fifty samples and control group of five samples. Hybrid experimental group and nanohybrid experimental group were again divided into five subgroups according to immersion medium, namely coffee, tea, coke, turmeric, and red wine. Each subgroup was comprised of ten samples. Both the control group samples were immersed separately into distilled water. Solutions were changed daily. Color measurements were obtained using spectrophotometer on the 1st, 7th, and 30th days. For statistical evaluation, analysis of variance and Tukey's tests were used at a significance level of 0.05. Results: Color change of materials in staining agents ranked in this increasing order: water

Fire-resistant hydrophobic nanocoated composite partition sheets

Composite partition sheets were prepared by vacuum infusion process using noncombustible glass fiber and waste nylon along with polyester matrix. The waste nylon materials obtained in the form of discarded fishing nets were reinforced in sheets with T90° orientation. They were then coated using two types of fumed silica nanopowders mixed in polyester resin. Two types of coated and corresponding bare hybrid composite samples were examined for their various properties. Appreciable values for mechanical properties were obtained for all the hybrid sheets which are more pronounced for the nanocoated sheets. Furthermore, horizontal flammability tests proved that the fumed silica-coated sheets have better flame-retardant characteristics. With constant heat flux of 50 W/m2, the specimens were investigated for the peak heat release rate (HRR) and fire reaction properties like total oxygen consumed, average specific mass loss rate, total smoke release, and average HRR which gave good results for the nanocoated sheets. Moreover, water-absorbing properties of the hybrid sheets were generally less and it was better in the case of hydrophobic fumed silica-coated samples. These low cost and less weight composite sheets were successfully developed and the results obtained were encouraging, which can be used as partition sheets in the construction of affordable buildings.

Wear and friction behavior of self-lubricating hybrid Cu-(SiC + x CNT) composites

In the present study, wear and friction behavior of Cu matrix composites reinforced with simultaneous SiC-nanoparticle and multi-wall carbon nanotube (CNT) reinforcements were investigated and a relationship for the theoretical calculation of the friction coefficient of the hybrid composites was presented. The hybrid composites showed higher wear resistance and lower friction coefficients compared to monolithic copper. The results indicate that among the synthesized composites, Cu-(2 vol% SiC + 4 vol% CNT) represented the highest wear resistance as well as relatively high hardness. In addition, a lower friction coefficient and a lower oscillation were observed with this sample, compared to other hybrid composite samples. This was attributed to the formation of a continuous and uniform lubricant layer on the wear surface. Flake formation-spalling were detected as the dominant wear mechanism for the hybrid composites.

Effect of seawater on the buckling behavior of hybrid composite plates

This paper addresses the effects of different stacking sequences and seawater on the buckling behavior of hybrid composite plates. For the buckling tests, 12-layered hybrid composite plates were produced using different combinations of carbon, E-glass and aramid fibers, with an epoxy resin system as the matrix (Araldite LY1564/Aradur 3486). The hybrid composite plates were designed at the symmetric orientation angles of [(0/90)3]s, [(30/−60)3]s, [(45/−45)3]s and an anti-symmetric orientation angle of [(0/90)3]2. The hybrid composite samples were divided into groups and were subjected to buckling tests after being kept in different settings for varying periods of time (room temperature for 90 days, Black Sea water for 90 days, Mediterranean Sea water for 90 days, Mediterranean Sea water for 150 days). In light of the data obtained from the tests, the buckling behaviors of the layered hybrid composite plates were examined. The highest critical buckling load occurred in the carbon/aramid/glass (CAG) hybrid samples with the stacking sequence of [(0/90)3]s, whereas the lowest critical buckling load occurred in the carbon/aramid/glass (CAG45) hybrid samples with the stacking sequence of [(45/−45)3]s. It was observed that the critical buckling loads of the samples immersed in seawater decreased when compared to the critical buckling loads of the samples kept at room temperature. It was also found that the critical buckling loads of the hybrid samples immersed in the Mediterranean Sea water, which has high salinity, were lower than the critical buckling loads of the hybrid samples immersed in the Black Sea water, which has lower salinity.

Mechanical Characteristics of Hybrid Composites with ±45° Glass and 0°/90° Stainless Steel Fibers.

Lack of energy dissipation is one of the shortcomings of conventional glass fiber reinforced composites. The addition of steel fibers to the conventional FRP composite to create a hybrid composite has been recently investigated as an option to address this limitation. The current literature is limited to composites reinforced with metal and non-metal fibers of the same alignment. In this study, hybrid and nonhybrid FRP composites of different layups, fiber content, and weave type were manufactured and subjected to hysteretic tensile loads. Woven glass fabrics in ±45° orientation were hybridized with unidirectional stainless steel fabrics in 0° and 90° orientations. This put the glass and steel layers in in-plane shear and normal stresses, respectively. The nonlinear stress–strain relationship, residual plastic strains, energy dissipation capability, and failure mechanisms of hybrid and nonhybrid composite type were compared. The hybrid composites presented improved energy dissipation, tensile strength, and stiffness when compared to nonhybrid ones. The applicability of an existing constitutive model that was originally developed for in-plane shear of conventional composites was investigated and refinements were proposed to present the hysteretic stress–strain relationship after addition of steel fibers. The refined model captured the increased plastic strain values and energy dissipation because of stainless steel fibers in the hybrid composite samples. An Armstrong–Frederick plasticity model was implemented to model the stress–strain relationship of the stainless steel composite samples.

Open Hole Tension of Coir-angustifolia Haw Agave Fibers Reinforced Hybrid Composite after Drilling Process

The aim of this paper is to investigate notched (open hole) tensile strength and normalized strength of coir and angustifolia Haw agave fibers as reinforcement of hybrid composites. Fabrication of hybrid composite with coir and agave fibers as reinforcement and polyester as the matrix was performed. Coir and agave fibers were formed like a mat.Notched (open hole) hybrid composites were drilled with 6 mm diameter of a hole at center of samples. Tensile testing was conducted to unnotched and notched hybrid composite. Results showed that tensile strength decrease after drilling of a hole in hybrid composite sample center. Normalized strength was range between approximately 75-98%. Tensile fracture of notched samples based on the view of images was around the hole due to concentration stress.

Creep and thermal behavior of quarry dust-silicon carbide hybrid particles reinforced ZA-27 alloy composites using stir casting technique

In this research, creep and thermal behavior of stir cast ZA-27 alloy-based hybrid composites modified with quarry dust (QD) and silicon carbide (SiCp) particles was investigated. ZA-27 hybrid composite samples reinforced with 10 wt% QD-SiCp particles containing varied weight percentage 0, 25, 50, 75, and 100% quarry dust was developed using stir casting technique. Dimensional stability (creep) evaluation and thermal behavior were performed to assess the performance of the produced modified composites. Thermal behavior was carried out using DSC thermal analyzer at operating temperatures of 0–500 °C to determine the behavior of the composites relative to temperatures, while the creep behavior (dimensional stability) was conducted using Dynamic Mechanical Analyzer (DMA 242E) at elevated temperature of 100 °C under a load of 3 N for 70 min. The results show that hybrid composites with designation B2 (50% SiCp:50%QD) and B3 (25% SiCp:75% QD) displayed superior creep resistance without dimensional instability; the highest dimensional change of 0.11 pct was observed in Bo (100% SiCp), while dimensional changes of < 0.05 pct was observed for unmodified alloy, B1 (75% SiCp:25% QD) and B4 (100% QD), respectively. However, superior elevated temperature was observed in sample designations Bo and B2, respectively, when compared with unmodified (unreinforced) alloy.

Dynamic behavior of geometrically complex hybrid composite samples in a Split-Hopkinson Pressure Bar system

The interfaces between layered materials play an important role for the overall mechanical behavior of hybrid composites, particularly during dynamic loading. Moreover, in complex-shaped composites, interfacial failure is strongly affected by the geometry and size of these contact interfaces. As preliminary work for the design of a novel sample geometry that allows to analyze wave reflection phenomena at the interfaces of such materials, a series of experiments using a Split-Hopkinson Pressure Bar technique was performed on five different sample geometries made of a monomaterial steel. A complementary explicit finite element model of the Split-Hopkinson Pressure Bar system was developed and the same sample geometries were studied numerically. The simulated input, reflected and transmitted elastic wave pulses were analyzed for the different sample geometries and were found to agree well with the experimental results. Additional simulations using different composite layers of steel and aluminum (with the same sample geometries) were performed to investigate the effect of material variation on the propagated wave pulses. The numerical results show that the reflected and transmitted wave pulses systematically depend on the sample geometry, and that elastic wave pulse propagation is affected by the properties of individual material layers.

Effects of fibre loading and moisture absorption on the tensile properties of hybrid Napier/glass/epoxy composites

The primary objective of this study was to investigate the effect of moisture absorption on the mechanical degradation of hybrid Napier/glass-epoxy composites. The hybrid Napier/glass-epoxy composites plates were produced by the vacuum infusion method using epoxy resin as a matrix. The hybrid composite specimens were tested after following 50 h of water immersion. The moisture content decreased as the glass fibre content increased. The wet and dry hybrid composite samples were subjected to tensile tests. The incorporation of the glass fibre into the Napier grass fibre-epoxy composites enhanced their tensile strength and tensile modulus. The tensile strength and tensile modulus of the hybrid Napier/glass-epoxy composites (24/6–70 vol%) were 43 MPa and 3.2 GPa, respectively. However, the tensile strength and tensile modulus properties highly degraded under wet conditions.

Investigation of behaviors of glass/epoxy laminate composites reinforced with carbon nanotubes under quasi-static punch shear loading

In this paper, in addition to investigation of the effects of adding of nanotubes on the tensile properties of epoxy matrix and glass/epoxy laminate composite, the effects of adding of nanotubes and the effect of indenter shape on quasi-static punch shear properties of glass/epoxy laminate are experimentally studied. Laminate nanocomposites have 12 layers of plain weave glass fibers which are made by hand lay-up method. Resin is composed of a two-component epoxy; Epon 828 as the base and Epikure F-205 as the curing agent. Multi-walled carbon nanotubes modified by hydroxid (–COOH) are used with 0%, 0.5% and 1% ratio in weight with respect to the matrix. In quasi-static punch shear tests, three indenters (flat, conical and ogival) are utilized. Tensile test results for nanomatrix show that the most changes are obtained on 0.5 wt.% specimen, in which the ultimate strength and strain energy are increased 22% and 17% respect to the neat sample, respectively. No distinct change was observed in tensile behavior of the hybrid composite samples by the addition of carbon nanotubes. Punch shear test results show that addition of carbon nanotubes reduces the contact force and the absorbed energy in ogival and conical indenters. In presence of nanotube particles, the maximum decreasing in the contact force and the absorbed energy happens in conical nose indenter with 23% and 26% decrease, respectively. Comparison of different indenters shows that in the neat samples, the maximum and minimum contact force belongs to the flat nose indenter (2.45 kN) and the ogival nose indenter (0.75 kN), respectively, while the maximum and minimum absorbed energy belongs to the conical nose indenter (13.5 J) and the flat nose indenter (10 J), respectively. Moreover, change of indenter geometry changes the failure mechanism, so that the failure of flat indenter is plugging and failure of sharp indenter is petaling.

Behaviour of Hybrid SiC/Jute Epoxy Composites Manufactured by Vacuum Assisted Resin Infusion

Natural fibre-reinforced polymer composites are standing in the limelight of investigations due to their light weight and availability from natural and renewable resources. Improved mechanical and physical behaviour is targeted through hybridisation with other reinforcing elements. This study investigates the potential of adding silicon carbide particles at volume contents ranging between 2 and 8% to jute fabric-reinforced epoxy composite to produce such hybrid composites. In contrast to the commonly applied processing technique of hand layup used to produce natural fibre-reinforced laminates, the vacuum-assisted resin infusion method was applied in this study to produce high quality laminates. Samples were tested for their mechanical behaviour through tensile, flexural and impact tests. Scanning electron microscopy was further performed to analyse the modes of failure of the composites. Finally, erosion tests were conducted, by directly sanding the hybrid composite samples to evaluate their erosion wear resistance. Results indicated that the addition of particles had a significant effect on the tensile, flexural, impact and erosion wear behaviour of the composites under investigation. Hybrid composites reinforced with 4 vol.% SiC exhibited acceptable mechanical properties. The behaviour was found to deteriorate at SiC contents beyond 4 vol.%.

Effect of Hybridizing and Optimization of TiC on the Tribological Behavior of Mg–MoS2 Composites

In the present study, the effects of TiC content on the microstructure, hardness, and wear property are to be investigated. Magnesium matrix hybrid composites reinforced with varying wt.% of TiC (0, 5, 10, 15, and 20) and a fixed wt.% of MoS2 (7.5) were produced by powder metallurgy. The microstructure of the hybrid composite samples was analyzed using optical microscopy. Elemental composition of sintered specimens was determined by energy dispersive X-ray spectroscopy (EDS) analysis. The Vicker's hardness test was performed in different locations on the sintered specimen surface with a load of 5 g and 15 s dwell time. The dry sliding wear test was carried out in a pin-on-disk wear testing machine at various load (5–30 N), velocity (0.5–3 m/s), and sliding distance (500–3000 m). Tribological investigation was statistically analyzed using Taguchi L27 orthogonal array with four factors at three levels. A graphical and numerical optimization technique was used to find the optimum value of TiC content using the predicted value of the responses. The tribological properties of the fabricated composites improved significantly compared to that of the magnesium matrix due to the combined effect obtainable by both reinforcements.

Effect of B4C/Fly Ash Addition on Wear and Mechanical Properties of Al-Cu-Mg Alloy

This research studied the effect of adding fly ash and boron carbide (B4C) particulates reinforcement on the mechanical properties and wear resistance of Al- 4.5% Cu- 1.18% Mg matrix alloy. Stir casting method has been used to fabricate the alloy and hybrid composite samples containing 2wt% of B4C and 5, 10, 15،20 wt % fly ash. The x-ray inspection revealed the dispersion of intermetallic compounds (Al2Cu,MgO and SiO2) Also, the mechanical properties have been evaluated, the results showed an increase in the tensile and yield properties with the increase of weight percentage of fly ash content up to 15 wt%, but the elongation decreased, while the hardness increased. Wear rate examination has been concluded by using pin on disc apparatus under different loads of (5, 10, 15) N, sliding velocities (1.413, 2.827, 4.241) mm/sec, and different times of (5, 10, 15) min. The results showed decrease in wear rate at 20% fly ash composite sample when compared with other composites samples and base alloy.

Embedding Graphene Nanoplates into MIL-101(Cr) Pores: Synthesis, Characterization, and CO2 Adsorption Studies

In this research, the equilibrium and dynamic adsorption studies of the CO2 upon the MIL-101(Cr) metal–organic framework (MOF) as well as its GNP hybrid composites, the MIL-101(Cr)/GNP, were performed. First, the hybrid composite samples were synthesized by adding various amounts of GNP in an in situ manner during the preparation of the MIL-101(Cr). The prepared materials were characterized through several physicochemical analyses, including powder X-ray diffraction (PXRD), adsorption of nitrogen at 77.4 K, Fourier transfer infrared (FT-IR) spectroscopy, thermal analysis (DTG), and field emission scanning electron microscopy (FESEM). It was demonstrated that the synthesized MIL-101(Cr)/GNP possessed a nearly similar crystal structure and morphology compared with those of the virgin sample. Next, the CO2 adsorption studies upon these sorbents were performed through a volumetric adsorption apparatus at 298 K and CO2 pressures of up to 40 bar using an in-house made rig. It was shown that the CO2 adsorption c...

Woven Kenaf/Kevlar Hybrid Yarn as potential fiber reinforced for anti-ballistic composite material

Woven Kenaf/Kevlar Hybrid Yarn is the combination of natural and synthetic fibers in the form of thread or yarn. The yarn is weaved to form a fabric type of fiber reinforced material. Then, the fabric is fabricated with epoxy as the resin to form a hybrid composite. For composite fabrication, woven fabric Kenaf/Kevlar hybrid yarn composite was prepared with vacuum bagging hand lay-up method. Woven fabric Kenaf/Kevlar hybrid yarn composite was fabricated with total fiber content of 40 % and 60 % of Epoxy as the matrix. The fiber ratios of Kenaf/Kevlar hybrid yarn were varied in weight fraction of 30/70, 50/50 and 70/30 respectively. The composites of woven fabric Kenaf/Epoxy and woven fabric Kevlar/Epoxy were also fabricated for comparison. The mechanical properties of five (5) samples composites were tested accordingly. Result has shown that of value of strength and modulus woven fabric Kenaf/Kevlar Hybrid Yarn composite was increased when the Kevlar fiber content increased. Therefore, among the hybrid composite samples result showed the woven fabric Kenaf/Kevlar Hybrid Yarn composites with the composition of 30/70 ratio has exhibited the highest energy absorption with 148.8 J which 28 % lower than Kevlar 100 % sample. The finding indicated there is a potential combination of natural fiber with synthetic fiber that can be fabricated as the composite material for the application of high performance product.