scholarly journals Electrical Resistivity, Tribological Behaviour of Multiwalled Carbon Nanotubes and Nanoboron Carbide Particles Reinforced Copper Hybrid Composites for Pantograph Application

2016 ◽  
Vol 2016 ◽  
pp. 1-18 ◽  
Author(s):  
N. Selvakumar ◽  
K. Gangatharan
Keyword(s):  
Electrical Resistivity ◽  
Hybrid Composites ◽  
Secondary Reinforcement ◽  
Copper Matrix ◽  
Tribological Behaviour ◽  
Wear Properties ◽  
Multiwalled Carbon ◽  
Nanoparticle Distribution ◽  
Fixed Weight ◽  
Uniform Dispersion

This work focuses on the influence and contribution of multiwalled carbon-nanotube (MWCNT)–boron carbide (B4C) to the mechanical and tribological properties of copper matrix composites. Different weight fractions of nano- B4C-containing fixed-weight fractions of MWCNT-reinforced copper composites were prepared using the entrenched cold-press sintering method of powder metallurgy. The wear losses of sintered Cu–MWCNT–B4C composites were investigated by conducting sliding tests in a pin-on-disc apparatus. The addition of reinforcements showed enhancements in the hardness and wear properties of the composites due to the uniform dispersion of the secondary reinforcement in the copper matrix and the self-lubricating effect of the MWCNTs. The effects of the nanoparticle distribution in the matrix, the worn surface morphology, and the elemental composition of the composites were characterized using high-resolution scanning electron microscopy and X-ray diffraction analysis. The electrical resistivity of the fabricated copper hybrid composite preforms was evaluated using a four-point probe tester. Our results highlight the use of experiential reinforcing limits of B4C on the wear and electrical and mechanical behaviour of copper composites.

The rheological behaviour and thermal ageing characteristics of PP/MWCNT/glass fibre multiscale composites

2021 ◽  
pp. 096739112199290
Author(s):  
N Rasana ◽  
K Jayanarayanan ◽  
Krishna Prasad Rajan ◽  
Aravinthan Gopanna
Keyword(s):  
Hybrid Composites ◽  
Rheological Behaviour ◽  
Strain Energy Release ◽  
Critical Stress Intensity Factor ◽  
Thermal Ageing ◽  
Multiwalled Carbon ◽  
Weight Percentage ◽  
Fixed Weight ◽  
Multiscale Composite ◽  
The Matrix

Multiscale hybrid composites were prepared using varying weight percentages (0 to 5) of multiwalled carbon nanotubes (MWCNTs) as nanofiller and a fixed weight percentage (20) of short glass fibres as micro filler (in polypropylene (PP) matrix. The shear and extensional viscosity of the composites was measured using a capillary rheometer. It was observed that even at higher shear rates the synergism of micro and nanofillers in the matrix significantly enhanced the melt viscosity. The complex nanotube network entanglement with micro fillers and PP chains imparted restrictions to the polymer chain movements. The prepared samples were subjected to thermal ageing at 100°C for 4 days in hot air oven. After ageing, multiscale composite with 3 wt% MWCNTs exhibited 28.57% enhancement in strain at break, whereas the tensile strength and modulus reduced by 6.8% and 8% respectively. The fracture toughness properties like strain energy release rate and critical stress intensity factor were not affected for multiscale composite at the optimum content of 3 wt% MWCNT, even after thermal ageing.

Alkali treatment and its effect on tribological properties of natrually woven coconut sheath polyester composite

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
I. Siva ◽  
J.T. Winowlin Jappes ◽  
Z. Szakal ◽  
Jacob Sukumaran
Keyword(s):  
Tribological Properties ◽  
Hybrid Composites ◽  
Alkali Treatment ◽  
Low Cost ◽  
Alkaline Treatment ◽  
Natural Fibres ◽  
Tribological Behaviour ◽  
Wear Properties ◽  
Low Friction ◽  
Sem Images

In the recent years natural fibres have drawn great interest for its bio-degradability, low cost and its availability in nature. Among different types of natural fibres, naturally woven coconut sheath fibres are one of the recently explored alternatives for synthetic fibres. These fibres are generally treated with alkali for enhancing mechanical properties and reinforcing characteristics. Tribological applications like gears, cams, bearings, etc. can be benefited from such composites. In most cases chemical treatment are done favouring the structural properties however, their influence on tribological properties are rather not considered. In the current research, hybrid composites (polyester resin with naturally woven coconut sheath (N) and glass fibres (G)) were tested against hardened steel counterface in a pin on disc configuration. Tests were performed at 40 N normal force and 3.5 m/s sliding velocity. From the results all hybrid combinations except (NNN) shows degrading wear properties with the alkaline treatment. The friction properties are modified by having low friction coefficients for all combinations except NGN and GGG hybrids. From the observed SEM images the surface morphology of NNN hybrid significantly differs from the rest of the combinations in both treated and untreated specimens. The partial removal of individual phase (resin) prevails in untreated specimen for which the fibres are highly visible. However, such phenomenon is not dominant in the alkali treated material showing better reinforcing behaviour complimenting low friction properties. The alkali treated specimen has reduced fibre size comparing the untreated specimen which results in low wear resistance. Compromise between friction and wear properties between each other the untreated fibres are best suited for tribological applications. Furthermore, investigations on treatment process and other treatments might have some influence in tribological behaviour.

Influence of nanostructured Cu on the mechanical properties of Cu–MWCNTs composites

2020 ◽  
Vol 111 (6) ◽  
pp. 469-478
Author(s):  
Lailesh Kumar ◽  
Santosh Kumar Sahoo ◽  
Syed Nasimul Alam
Keyword(s):  
Wear Mechanisms ◽  
Mechanical Milling ◽  
Wear Behavior ◽  
Homogeneous Distribution ◽  
Wear Properties ◽  
Multiwalled Carbon ◽  
Solid Solution Strengthening ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Uniform Dispersion

Abstract In the present investigation, Cu-multiwalled carbon nanotubes (MWCNTs) nanocomposites were developed through mechanical milling using nanostructured Cu as a matrix and MWCNTs as nanofillers. The influence of nanostructured Cu on the microstructure, microhardness, and wear behavior of Cu-MWCNTs nanocomposites was also studied. The crystallite size of nanostructured Cu powder via mechanical milling for 25 h was found to be 16 nm. The major challenge associated with the development of Cu-MWCNTs nanocomposites is the uniform dispersion of the CNTs in the Cu matrix, which was addressed by incorporating nanostructured Cu, leading to the homogeneous distribution of CNTs and good bonding between the CNTs and the Cu matrix. A significant improvement in relative density and microhardness with <3 wt.% MWCNTs was observed compared to pure asreceived Cu and its composites. The hardness of Cu-3 wt.% MWCNTs nanocomposite developed using nanostructured Cu were achieved at <800 MPa, which is about 2.3 times higher than that of the as-received Cu sample (~ 359 MPa). The significant increment in mechanical and wear properties mainly originates from fine-grain strengthening effects and solid solution strengthening. The wear mechanisms in the various nanostructured Cu-MWCNTs composites were studied in detail and oxidation wear was identified as one of the main wear mechanisms.

scholarly journals Mechanical and tribological properties of Al 7075 /SiC/ Graphite hybrid composites processed by powder metallurgy technique

2019 ◽  
Vol 8 (11) ◽  
pp. 1210-1215
Keyword(s):  
Tribological Properties ◽  
Hybrid Composites ◽  
Experimental Investigations ◽  
Wear Loss ◽  
Metal Composite ◽  
Tribological Behaviour ◽  
Wear Properties ◽  
Mechanical And Tribological Properties ◽  
Al 7075 ◽  
Pin On Disc

The metal matrix composite strengthened with ceramic material of carbide (SiC) has smart mechanical characteristics. Metal-based composites, however, demand progress in their friction and tribological characteristics. In this work-study an effort is made to design a completely new material through the method of metallurgy by adding graphite, which acts as a solid lubricant. This study explored the effect of graphite on the tribological behaviour of hybrid composite Al 7075/5 wt. % SiC / X wt. % graphite (X=10, 5 and 0). The research confirms the performance of wear properties by incorporating graphite into the composite. The sic-graphite reinforced Al 7075 (aluminium alloy 7075) was studied. Metallurgy route was used to prepare the composites. Microstructures, the mixture of materials, wear and wear resistance properties were analyzed by optical micro cope and scanning electron microscope, XRD, and pin-on-disc apparatus. The freshly developed metal composite has significant improvement in tribological properties with a mixture 5% silicon carbide (SiC) and 5% graphite. The experimental investigations confirm that a sliding distance of one thousand meters and a sliding velocity of 1.5 m / s with an applied load of 5 N leads to minimum wear loss of 0.01062g and coefficient of friction as 0.1278

Influence of Multiwall Carbon Nanotube on mechanical and wear properties of Copper – Iron composite

2020 ◽  
Vol 17 (1) ◽  
pp. 7570-7576 ◽  
Author(s):  
H. Sh. Hammood ◽  
S. S. Irhayyim ◽  
A. Y. Awad ◽  
H. A. Abdulhadi
Keyword(s):  
Carbon Nanotubes ◽  
Volume Fraction ◽  
Hybrid Composites ◽  
Hydraulic Press ◽  
Dry Sliding Wear ◽  
Multiwall Carbon Nanotube ◽  
Wear Properties ◽  
Sem Images ◽  
Wear Rates ◽  
Multiwall Carbon

Multiwall Carbon nanotubes (MWCNTs) are frequently attractive due to their novel physical and chemical characteristics, as well as their larger aspect ratio and higher conductivity. Therefore, MWCNTs can allow tremendous possibilities for the improvement of the necessarily unique composite materials system. The present work deals with the fabrication of Cu-Fe/CNTs hybrid composites manufactured by powder metallurgy techniques. Copper powder with 10 vol. % of iron powder and different volume fractions of Multi-Wall Carbon Nanotubes (MWCNTs) were mixed to get hybrid composites. The hybrid composites were fabricated by adding 0.3, 0.6, 0.9, and 1.2 vol.% of MWCNTs to Cu- 10% Fe mixture using a mechanical mixer. The samples were compressed under a load of 700 MPa using a hydraulic press to compact the samples. Sintering was done at 900°C for 2 h at 5ºC/min heating rate. The microscopic structure was studied using a Scanning Electron Microscope (SEM). The effect of CNTs on the mechanical and wear properties, such as micro-hardness, dry sliding wear, density, and porosity were studied in detail. The wear tests were carried out at a fixed time of 20 minutes while the applied loads were varied (5, 10, 15, and 20 N). SEM images revealed that CNTs were uniformly distributed with relative agglomeration within the Cu/Fe matrix. The results showed that the hardness, density, and wear rates decreased while the percentage of porosity increased with increasing the CNT volume fraction. Furthermore, the wear rate for all the CNTs contents increased with the applied load.

Studies on mechanical property and wear behaviour of AA7075 hybrid composites prepared by a conventional casting method

2021 ◽  
pp. 095440892110349
Author(s):  
V Vignesh Kumar ◽  
K Raja ◽  
T Ramkumar ◽  
M Selvakumar ◽  
TS Senthil Kumar
Keyword(s):  
Boron Nitride ◽  
Boron Carbide ◽  
Hybrid Composites ◽  
Stir Casting ◽  
Wear Behaviour ◽  
Tensile Behaviour ◽  
Wear Properties ◽  
Casting Technique ◽  
Reciprocating Wear ◽  
Sliding Distance

The research article addresses the reciprocating wear behaviour of hybrid AA7075 reinforced with boron carbide and boron nitride through a stir-casting technique. The experiment involved varying wt.% of the secondary particle boron carbide (3, 6 and 9) while boron nitride (3) was kept as constant. The hybrid composites were characterised using scanning electron microscopy coupled with energy dispersive spectroscopy. The hardness and tensile behaviour of the hybrid composites were evaluated. Reciprocating wear behaviour of the hybrid composites were examined using a tribometer by varying the wear parameters such as load and sliding distance. The results revealed that AA7075/6boron carbide/3boron nitride had better hardness, tensile and wear properties. The surface morphology of the wear samples was analysed using SEM.

Effect of weight fraction and particle size of CRT glass on the tribological behaviour of Mg-CRT-BN hybrid composites

2017 ◽  
Vol 116 ◽  
pp. 338-350 ◽  
Author(s):  
P.M. Gopal ◽  
K. Soorya Prakash ◽  
S. Nagaraja ◽  
N. Kishore Aravinth
Keyword(s):  
Particle Size ◽  
Hybrid Composites ◽  
Weight Fraction ◽  
Tribological Behaviour

Effect of Reinforcement and Tribological Behaviour of AA 7068 Hybrid Composites Manufactured through Powder Metallurgy Techniques

2017 ◽  
Vol 867 ◽  
pp. 19-28 ◽  
Author(s):  
J. Lakshmipathy ◽  
Subburaj Rajesh Kannan ◽  
K. Manisekar ◽  
S. Vinoth Kumar
Keyword(s):  
Sintering Temperature ◽  
Hybrid Composites ◽  
High Strength ◽  
Phase Changes ◽  
Wear Loss ◽  
X Ray Diffraction ◽  
Tribological Behaviour ◽  
Different Temperatures ◽  
Pin On Disc ◽  
Sliding Distance

In this article, an attempt was made to study the mechanical behaviour of AA7068 - 6 vol. % of MoS2 - X vol. % of WC (X = 0, 5, 10 and 15) hybrid aluminium composites produced by blend–press–sinter methodology. Compacted Powders (700MPa) were sintered at different temperatures (450 0c, 500 0c and 550 0c ) in order to find the influence of sintering temperature on mechanical properties and tribological behavior of AA7068 hybrid composites.The sintered samples have been characterized by x-ray diffraction (XRD) method for identification of phases and also to investigate the phase changes. The change in density, hardness and porosity values of composites were reported. The composite with 15 vol. % of tungsten carbide and 6 vol. % of MoS2 showed the highest hardness and density at the sintering temperature range of 550 0c. Pin-on-disc type apparatus was used for determining the wear loss occurring at different conditions. The hybridization of the two reinforcements enhanced the wear resistance of the composites, especially under high applied load, sliding distance and sliding speeds. Due to this, the hybrid aluminium composites can be considered as an outstanding material where high strength and wear-resistant components are of major importance, predominantly in the aerospace and automotive engineering sectors. The morphology of the wear debris and the worn out surfaces were analyzed to understand the wear mechanisms.

Si3N4/Graphene binary particles reinforced hybrid titanium composites and their characterization

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tugba Mutuk ◽  
Mevlüt Gürbüz
Keyword(s):  
Hybrid Composite ◽  
Hybrid Composites ◽  
Graphene Nanoplatelets ◽  
Powder Metallurgy Method ◽  
Matrix Composites ◽  
Compressive Behavior ◽  
Titanium Matrix ◽  
Wear Properties ◽  
Titanium Matrix Composites ◽  
Matrix Density

Abstract This study reports on silicon nitride (Si3N4) and graphene nanoplatelets binary powder reinforced hybrid titanium composites obtained by a powder metallurgy method. Si3N4 powder was added at 3 wt.% and graphene nanoplatelets were added in various amounts (0.15, 0.30, 0.45, 0.60 wt.%) in the titanium matrix. Density, micro-Vickers hardness, compressive behavior, wear properties and microstructure of the hybrid composites were evaluated. Addition of different percentages of graphene nanoplatelets and 3 wt.% Si3N4 to the titanium matrix composites significantly enhanced mechanical properties. The highest hardness (634 HV) and compressive strength (1458 MPa) values were measured for 0.15 wt.% graphene nanoplatelets and 3 wt.% Si3N4 added titanium hybrid composite. The lowest mass loss and wear rate (Δm = 4 mg, W = 6.1×10–5 mm3 (N m)–1) values were measured for the same 0.15 wt.% graphene nanoplatelets and 3 wt.% Si3N4 added titanium hybrid composite compared with pure Ti.

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