Tribological, Mechanical, and Microstructural of Multiwalled Carbon Nanotubes/Short Carbon Fiber Epoxy Composites

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
O. J. Gbadeyan ◽  
Krishnan Kanny ◽  
Mohan Turup Pandurangan
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Fiber ◽  
Wear Rate ◽  
Multiwalled Carbon Nanotubes ◽  
High Heat ◽  
Structural Development ◽  
Multiwalled Carbon ◽  
Short Carbon Fiber ◽  
Uniform Dispersion ◽  
Short Carbon

In the present work, composites were developed with novel combination of particular fillers and fibers for an automotive brake system. The influence of short carbon fiber (SCF) on wear rate, coefficient of friction (CoF), modulus, compressive strength, hardness, and surface morphology of worn surface were examined. This investigation confirmed that 0.1% multiwalled carbon nanotubes (MWCNTs) reduced wear rate, CoF for all combinations of composite with carbon fiber. Results indicate that 0.1% (MWCNTs) and 10% SCF-filled composite had superior properties. This performance may be attributed to the uniform dispersion of fiber and the synergistic effect of SCF and MWCNTs, acting in concert that formed a more stable structure resulting in a high strength, stiffness, tougher, and high-heat absorption. Scanning electron microscopy (SEM) microstructure subsequently performed show change in structural development with a corresponding increase of the incorporation of SCF and MWCNTs, which eventually explained the improved properties of composite.

scholarly journals Experimental analysis of composite scarf adhesive joints modified with multiwalled carbon nanotubes under bending and thermomechanical impact loads

2019 ◽  
Vol 234 (1) ◽  
pp. 48-64 ◽  
Author(s):  
UA Khashaba ◽  
Ramzi Othman ◽  
IMR Najjar
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Fiber ◽  
Multiwalled Carbon Nanotubes ◽  
Adhesive Joints ◽  
Impact Loads ◽  
Fiber Reinforced ◽  
Multiwalled Carbon ◽  
Impact Tests ◽  
Carbon Fiber Reinforced ◽  
The Impact

Scarf adhesive joints have attracted an increasing attention in joining/repairing of carbon fiber reinforced epoxy composite structures due to their zero eccentricity, which provides lower stress distribution across the adhesive layer and better aerodynamic surfaces compared to other bonded joints. The main objective of this study is to evaluate the performance of the scarf adhesive joints in carbon fiber reinforced epoxy composites under thermomechanical impact loads, which is very important for the aerospace and automotive industries. The adhesive was modified with optimum percentage of multiwalled carbon nanotubes. The impact tests were performed at 25 ℃, 50 ℃, and 75 ℃. The residual flexural properties of the unfailed impacted joints were measured using three-point bending test. Results from impact tests at 25 ℃, 50 ℃, and 75 ℃ showed improvement in the impact bending stiffness of the modified scarf adhesive joints by 8.3%, 7.4%, and 11.8% and maximum contact force by 15.6%, 21.3%, and 18.9%, respectively. The energy at failure of the modified scarf adhesive joints with multiwalled carbon nanotubes was improved by 15.2% and 16.4% respectively at 25 ℃ and 50 ℃. At test temperature of 75 ℃, the scarf adhesive joints have hysteresis load–displacement behavior and energy–time curve with rebound energy of 35% and absorbed (damage) energy of 65%. The residual flexural strength of the modified and unmodified scarf adhesive joints is 98.2% and 86.1% respectively, while their residual moduli have remarkable decrease to 71.7% and 81.3%.

Experimental Investigation of the Machinability of Polycarbonate Reinforced With Multiwalled Carbon Nanotubes

2005 ◽  
Vol 128 (2) ◽  
pp. 465-473 ◽  
Author(s):  
J. Samuel ◽  
R. E. DeVor ◽  
S. G. Kapoor ◽  
K. J. Hsia
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Fiber ◽  
Multiwalled Carbon Nanotubes ◽  
Cutting Forces ◽  
Fiber Composite ◽  
Chip Morphology ◽  
Surface Characteristics ◽  
Carbon Fiber Composite ◽  
Multiwalled Carbon ◽  
Machined Surface

The machinability of a polycarbonate nanocomposite containing multiwalled carbon nanotubes is investigated and contrasted with its base polymer and with a conventional carbon fiber composite. The material microstructures are characterized using transmission electron and scanning electron microscopy methods. Micro-endmilling experiments are conducted on the three materials. Chip morphology, machined surface characteristics, and the nature of the cutting forces are employed as machinability measures for comparative purposes. Polycarbonate chips are seen to transition from being discontinuous to continuous as the feed-per-tooth (FPT) increases, while, at all FPT values the nanocomposite is seen to form comparatively thicker continuous chips. The nanocomposite and the carbon fiber composite are seen to have the lowest and the highest magnitudes, respectively, for both the surface roughness and cutting forces. Shearing along the nanotube-polymer interface and better thermal conductivity are speculated to be the mechanisms responsible for the observations seen in the nanocomposite.

scholarly journals Thermal Conductivity of Carbon Nanoreinforced Epoxy Composites

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
C. Kostagiannakopoulou ◽  
E. Fiamegkou ◽  
G. Sotiriadis ◽  
V. Kostopoulos
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Fiber ◽  
Multiwalled Carbon Nanotubes ◽  
Epoxy Matrix ◽  
Epoxy Composites ◽  
Graphite Nanoplatelets ◽  
Multiwalled Carbon ◽  
Micromechanical Models ◽  
Carbon Fiber Epoxy

The present study attempts to investigate the influence of multiwalled carbon nanotubes (MWCNTs) and graphite nanoplatelets (GNPs) on thermal conductivity (TC) of nanoreinforced polymers and nanomodified carbon fiber epoxy composites (CFRPs). Loading levels from 1 to 3% wt. of MWCNTs and from 1 to 15% wt. of GNPs were used. The results indicate that TC of nanofilled epoxy composites increased with the increase of GNP content. Quantitatively, 176% and 48% increase of TC were achieved in nanoreinforced polymers and nanomodified CFRPs, respectively, with the addition of 15% wt. GNPs into the epoxy matrix. Finally, micromechanical models were applied in order to predict analytically the TC of polymers and CFRPs. Lewis-Nielsen model with optimized parameters provides results very close to the experimental ones in the case of polymers. As far as the composites are concerned, the Hashin and Clayton models proved to be sufficiently accurate for the prediction at lower filler contents.

scholarly journals CVD Synthesis of Hierarchical 3D MWCNT/Carbon-Fiber Nanostructures

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Toma Susi ◽  
Albert G. Nasibulin ◽  
Hua Jiang ◽  
Esko I. Kauppinen
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Fiber ◽  
Multiwalled Carbon Nanotubes ◽  
Carbon Fibers ◽  
Gas Flow ◽  
Carbon Precursor ◽  
Optimal Temperature ◽  
Multiwalled Carbon ◽  
Cvd Synthesis

Multiwalled carbon nanotubes (MWCNTs) were synthesized by CVD on industrially manufactured highly crystalline vapor-grown carbon fibers (VGCFs). Two catalyst metals (Ni and Fe) and carbon precursor gases (C2H2and CO) were studied. The catalysts were deposited on the fibers by sputtering and experiments carried out in two different reactors. Samples were characterized by electron microscopy (SEM and TEM). Iron was completely inactive as catalyst with bothC2H2and CO for reasons discussed in the paper. The combination of Ni andC2H2was very active for secondary CNT synthesis, without any pretreatment of the fibers. The optimal temperature for CNT synthesis was750∘C, with total gas flow of 650 cm3min⁡−1ofC2H2,H2, and Ar in 1.0:6.7:30 ratio.

scholarly journals Uniform Dispersion of Multiwalled Carbon Nanotubes in Copper Matrix Nanocomposites Using Metal Injection Molding Technique

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ali Samer Muhsan ◽  
Faiz Ahmad ◽  
Norani M. Mohamed ◽  
Puteri Sri Melor Megat Yusoff ◽  
Muhammad Rafi Raza
Keyword(s):  
Carbon Nanotubes ◽  
Injection Molding ◽  
Multiwalled Carbon Nanotubes ◽  
Elevated Temperatures ◽  
Metal Injection Molding ◽  
Ni Catalyst ◽  
Multiwalled Carbon ◽  
Uniform Dispersion ◽  
Pure Cu ◽  
Matrix Nanocomposites

This work presents a novel fabrication approach of multiwalled carbon nanotubes (MWNTs) reinforced copper (Cu) matrix nanocomposites. A combination of nanoscale dispersion of functionalized MWNTs in low viscose media of dissolved paraffin wax under sonication treatment followed by metal injection molding (MIM) technique was adopted. MWNTs contents were varied from 0 to 10 vol.%. Information about the degree of purification and functionalization processes, evidences on the existence of the functional groups, effect of sonication time on the treated MWNTs, and microstructural analysis of the fabricated Cu/MWNTs nanocomposites were determined using TEM, EDX, FESEM, and Raman spectroscopy analysis. The results showed that the impurities of the pristine MWNTs such as Fe, Ni catalyst, and the amorphous carbon have been significantly removed after purification process. Meanwhile, FESEM and TEM observations showed high stability of MWNTs at elevated temperatures and uniform dispersion of MWNTs in Cu matrix at different volume fractions and sintering temperatures (950, 1000 & 1050°C). The experimentally measured thermal conductivities of Cu/MWNTs nanocomposites showed remarkable increase (11.25% higher than sintered pure Cu) with addition of 1 vol.% MWNTs, and slight decrease below the value of sintered Cu at 5 and 10 vol.% MWNTs.

Synergy effects of graphene and multiwalled carbon nanotubes hybrid system on properties of epoxy nanocomposites

2017 ◽  
Vol 36 (9) ◽  
pp. 685-695 ◽  
Author(s):  
ZA Ghaleb ◽  
M Mariatti ◽  
ZM Ariff
Keyword(s):  
Thin Film ◽  
Carbon Nanotubes ◽  
Electrical Properties ◽  
Multiwalled Carbon Nanotubes ◽  
Multiwalled Carbon ◽  
Electrical Percolation ◽  
Uniform Dispersion ◽  
Synergy Effects ◽  
Electrical Percolation Threshold ◽  
Film Nanocomposites

Tensile and electrical properties of graphene nanopowder (GNP) and multiwalled carbon nanotubes (MWCNT) filled epoxy thin film nanocomposites were investigated. In addition, synergy effects of various mixture ratios of GNP–MWCNT hybrids on the properties of the epoxy thin film nanocomposites were evaluated. It was found that the addition of GNPs or MWCNTs decreased the tensile properties compared to that of unfilled epoxy. The electrical percolation threshold of MWCNT/epoxy was found to be 0.8 vol%. Addition of only 0.1 vol% GNPs results in significant improvement in the electrical properties of the composites. Enhanced tensile and electrical properties in the GNP–MWCNT/epoxy hybrid were achieved with GNP–MWCNT ratio of 0.1:0.4. Morphological analysis confirmed the uniform dispersion of both GNPs and MWCNTs within the epoxy matrix. For the hybrid GNP–MWCNT filler system (i.e., with the 0.1:0.4 ratio), MWCNTs were seen to align themselves on the GNPs surfaces creating an interconnected strong nanofiller network in the epoxy.

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