Influence of wear of carbon nanotube grown on carbon surfaces on the mechanical and electrical properties of composite materials (original) (raw)
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Tribological behaviour and wear of carbon nanotubes grafted on carbon fibres
Composites Part A: Applied Science and Manufacturing, 2015
Carbon nanotubes (CNTs) grafted on fibres are widely used to reinforce composites in order to improve their mechanical properties. This study concerned the tribological properties of CNTs grafted on carbon fibres by the flame method. The aim of this study was to determine whether CNTs on fibres suffer damage under stress, similar to those applied during composite manufacturing, which can damage composite properties, particularly fibre/matrix adhesion. For this purpose, reciprocating friction tests were performed to examine the resistance of CNTs and highlight a wear mechanism. The results showed that the presence of CNTs increased the coefficient of friction in the first friction cycles and then decreased it to close to the COF of the fibre without CNTs. The wear mechanism showed that after a small number of friction cycles, the CNTs were flattened out and formed a transfer film.
Tribological behaviour and adhesion of carbon nanotubes grafted on carbon fibres
Tribology International, 2016
Carbon nanotubes (CNTs) grafted on fibres are widely used to reinforce composites and improve the fibre/matrix interface. This study concerned the tribological and adhesion properties of CNTs grafted on carbon fibres by the flame method. Reciprocating friction and adhesion tests were performed to examine the resistance of the CNTs on the fibres in different grafting conditions (various catalysts). Friction results show that under a normal load higher than 1 N, CNTs are totally removed after 2000 cycles of friction with catalyst n.2 while they are still present on the surface with catalyst n.1. Adhesion tests show that CNTs are quite resistant to the tack test, and that the CNTs/CFs interfaces seem instantaneously more resistant with the use of catalyst n.2.
Journal of Engineering …, 2009
Carbon nanotubes were grown directly on carbon fibres using the chemical vapor deposition technique. The effects of reaction temperature (800-900 o C) and hydrogen gas flowrate (100-300 ml/min) on the morphology of the carbon nanotube coating were investigated. Carbon nanotubes produced were characterized using scanning electron microscope and transmission electron microscope. The resulting fibres were compounded with polypropylene to produce carbon fibre reinforced polypropylene composites. The tensile properties of these composites were determined to investigate the effects of the carbon nanotubes on the overall performance of the composites. The optimum treatment condition that produced the thickest coating of carbon nanotubes was obtained at 800 o C and 300 ml/min hydrogen gas flowrate. The composite sample obtained under these conditions demonstrated remarkable enhancement in tensile properties compared to composites made from as-received carbon fibres, whereby an increment of up to 52% and 133% was observed for the tensile strength and modulus respectively.
Nano-engineered composites: interlayer carbon nanotubes effect
Materials Research, 2013
The concept of carbon nanotube interlayer was successfully introduced to carbon fiber/epoxy composites. This new hybrid laminated composites was characterized by Raman spectroscopy, X-ray diffraction, scanning electron microscopy and tensile tests. An increase on peak stress close to 85% was witnessed when CNTs interlayer with 206.30 mg was placed to carbon fiber/epoxy laminates. The failure mechanisms are associated to CNTs distribution between and around carbon fibers. These CNTs are also responsible for crack bridging formation and the increase on peak stress. Initial stiffness is strongly affected by the CNT interlayer, however, changes on stiffness is associated to changes on nano/micro-structure due to damage. Three different behaviors can be described, i.e. for interlayers with ≈ 60 mg of CNT the failure mode is based on cracks between and around carbon fibers, while for interlayers with CNT contents between 136 mg and 185 mg cracks were spotted on fibers and inside the CNT/matrix mix. Finally, the third failure mechanism is based on carbon fiber breakage, as a strong interface between CNT/matrix mix and carbon fibers is observed.
In this work, the wear behavior of carbon nanotube/epoxy nanocomposites produced with varying ratios of multi-walled nanotube (MWCNT) (0.5, 1, 1.5, 2 wt %) was examined. MWCNTs have external diameter of 5-50 nm and lengths of 10-30 microns. MWCNFs were incorporated to the epoxy matrix using an ultrasonic homogenizer. Wear tests were carried out using a pin-on-disk test machine where a disc of epoxy/CNTs nanocomposite (90 mm in diameter and 4 mm in thickness) was used under a ball of steel (8 mm of diameter). The surface roughness of the specimens was about 0.1 μm Ra. Sliding distance was 500 m with a sliding speed of 0.44 m/s and a loads of 5, 10, 15 N were applied. As a result, the friction coefficient and surface roughness was measured. Lastly, wear surfaces were studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM) in order to determine the wear mechanism.
Materials Today: Proceedings, 2018
The different materials used to improve the mechanical strengths such as carbon fibers, CNTs, and other alloy's. The present study focus on the iron based metal matrix composites with charcoal, unpurified and purified CNTs as a reinforcement with the varying percentage of each constituent from 1 to 5 weight %. The wear testing is carried out for five different pin loading varying from 1 to 5 kg. It is observed that as a percentage of the CNTs increase, the material shows more wear resistance characteristics. Experimental results confirmed that CNT based MMC is much tougher than the charcoal based MMC.
Carbon, 2013
Functionalization of multi-wall carbon nanotubes (MWCNTs) was achieved by grafting carboxyl groups and amino groups. Fourier transform infrared spectroscopy was used to detect the changes produced by functional groups on the surface of the MWCNTs. Three different MWCNTs were incorporated into epoxy resin and the friction and wear behavior of MWCNT/epoxy composites was investigated using a M-2000 wear testing machine at different sliding speeds under different applied loads. Scanning electron microscopy was used to observe the worn surfaces of the samples. The results indicated that the functional groups had been grafted on the surface of MWCNTs. Compared with neat epoxy, the composites with MWCNTs showed a lower friction coefficient and wear rate, and the wear rate decreased with the increase of MWCNT loading. Combining epoxy resin with MWCNTs is an efficient method to improve the wear resistance and decrease the coefficient of friction.
MRS Proceedings, 2015
Aligned multi-walled carbon nanotubes were grown on carbon fiber surface in order to provide a way to tailor the thermal, electrical and mechanical properties of the fiber-resin interface of a polymer composite. As the deposition temperature of the nanotubes is very high, an elevated exposure time can lead to degradation of the carbon fiber. To overcome this obstacle we have developed a deposition technique where the fiber is exposed to an atmosphere of growth for just one minute, and different concentrations of precursor solution were used.
Microstructure and Bonding Strength of Carbon Nanotubes Directly Grown on a Carbon Fiber Substrate
Carbon nanotubes (CNTs) are directly grown on a carbon fiber (CF) surface using chemical vapor deposition to improve the interfacial properties of the CF composite. To characterize the interfacial properties quantitatively, the microstructure of the interface and the bonding strength of the CNTs on the CF surface were systematically investigated in this study. Through the observation of the microstructure by high-resolution transmission electron microscope, the interface between the CNT and the CF surface was found to consist of the covalent bonding. This interfacial structure observed was confirmed through a molecular dynamic (MD) simulation. Finally, the bonding strength of the CNTs on the CF surface was measured by separating a bundle of CNTs from the CF surface and compared with the calculated results from MD simulation, again demonstrating that the covalent bonds were formed at the interface between CF surface and CNTs.
Reasons of adding carbon nanotubes into composite systems - review paper
Mechanics and Mechanical Engineering, 2017
The Inclusion of CNT in the laminated composite system was found to increase the energy absorption of the whole composite after impact. The main important criteria is happened CNTs, which have good interfacial adhesion strong bonding with the matrix. Thus, it will be improve the properties/performance of the composite. Therefore, in current review paper the concentration/amount of the CNT, in term of loading, affect the performance of the composite and the mechanism on how the presence of CNT tends to absorb high amount of energy after impact have been discussed.