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1

Thermoelastic vibration characteristics of asymmetric annular porous reinforced with nano-fillers microplates embedded in an elastic medium: CNTs Vs. GNPs

Arshid Ehsan, Amir Saeed, Loghman Abbas

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 2

art. no. e100, 2023

EN

Due to the vast usage of metal foam structures in branches of science, reinforcing them with nano-fillers makes them more convenient. Hence, in the current study, vibration characteristics of functionally graded porous nanocomposite (FGPN) annular microplates are taken into consideration. Two kinds of nano-fillers, namely Carbon nanotubes (CNTs) and Graphene nanoplatelets (GNPs), are selected as the reinforcements to analyze and compare their effect on the microstructure’s vibrational response. The mentioned nano-fillers are dispersed according to four patterns which affect various mechanical properties of the structure. Similarly, based on given functions which are called porosity distributions, pores are placed in thickness course of the microstructure. Then, its properties are determined via employing Halpin-Tsai and extended rule of mixture micromechanics models. Using the first-order shear deformation theory (FSDT), modified couple stress theory (MCST), and Hamilton’s principle for dynamic systems, governing motion equations and related boundary conditions are derived in asymmetric state, and then, they are solved, and natural frequencies and corresponding mode shapes are extracted with the help of generalized differential quadrature method (GDQM). By validating the results in simpler conditions, effects of the most important parameters are examined. It is found that GNPs are more effective in reinforcing the structure than CNTs. Also, about 15~18 percent reduction in frequencies is seen by increasing the porosity up to seventy percent.

2

Size-dependent coupled bending-torsional vibration of functionally graded carbon nanotube reinforced composite Timoshenko microbeams

Dehkordi Hamid Reza Balali, Beni Yaghoub Tadi

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 3

art. no. e186, 2023

EN

This paper investigates the free vibration of a carbon nanotube-reinforced composite Timoshenko microbeam considering the effect of axial load and bending-torsion coupling. The microbeam properties are developed based on the micromechanical model concerning the extended rule of mixtures. The governing equations of motion are derived using the modified couple stress theory and Hamilton’s principle. The uniform nanotube distribution and three functionally graded distributions are considered for the carbon nanotube-reinforced composite microbeam. The generalized differential quadrature method is applied to the governing equations for deriving the natural frequency under different boundary conditions. Next, the effects of different parameters, including nanotube distribution, geometric characteristics of microbeam, material length scale, and nanotube volume fraction, on the natural frequency are demonstrated through different tables and diagrams. Among obtained results is the significant effect of the carbon nanotube volume fraction on the natural frequency of the microbeam. Also, the nonconformity between the mass and elastic axes leads to the natural frequency reduction. The comparison between obtained results and results of other credible papers confirms the validity of obtained results.

3

Multimodal machine learning approach for exploring the 28-day compressive strength of nanomaterials-reinforced cement composites

Yang Jinlong, Zeng Bowen, Hang Ziyan, Fan Yucheng, Ni Zhi, Feng Chuang, Liu Chuang, Yang Jie

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 3

art. no. e202, 2023

EN

Accurately predicting the 28-day compressive strength (CS) of carbon nanotubes-reinforced cement composites (CNTRCCs) and graphene oxide-reinforced cement composites (GORCCs) is crucial for accelerating their potential application in civil engineering. However, traditional experimental and theoretical modeling methods suffer from problems, including time-consuming, costly, and inefficient. Moreover, it is also challenging to consider the effects of multiple coupling factors. In this work, a multimodal machine learning (ML) approach is proposed as the first attempt to explore the complex relationships between the CS of hybrid system containing both CNTRCCs and GORCCs. The proposed multimodal ML shows great potential in estimating the nanomaterials-reinforced cement composites with a coefficient of determination (R2) of 0.96, surpassing the single-modal ML approaches. The results demonstrate the effectiveness of the developed model in accurately predicting the 28-day CS of hybrid system containing both CNTRCCs and GORCCs. Shapley additive explanations (SHAP) analysis illustrates that the optimal concentration of CNT is approximately 0.5 wt%, and preferred length of CNT and sheet size of GO are within a range of 20–30 μm and below 10 μm, respectively. Additionally, the enhancement effect of a single-layer GO is better than its multilayer counterparts.

4

Effect of porosity and characteristics of carbon nanotube on the nonlinear characteristics of a simply-supported sandwich plate

Bidgoli E. Mohammad-Rezae, Arefi Mohammad

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 3

art. no. e214, 2023

EN

This paper presents geometric-based nonlinear formulation of a composite sandwich plate on the elastic foundation based on first-order shear deformation theory. The composite sandwich plate is fabricated from a porous core integrated with two carbon-nanotubes-reinforced face sheets. After developing the kinematic relations based on first-order shear deformation theory, the geometric nonlinearity is accounted based on von-Karman-type nonlinearity. Porosity of the core is modeled based on two known models in terms of porosity coefficient. After presentation of the effective material properties of the core and the carbon nanotube reinforcement in terms of porosity coefficient, volume fraction of carbon nanotube, and basic material properties, the nonlinear governing equations are derived using Hamilton’s principle. Galerkin’s approach is applied to reduce nonlinear governing equations of motion to an ordinary time-dependent differential equation. The nonlinear frequency is analytically found based on linear frequency and initial boundary conditions. Before presentation of full numerical results, a comprehensive comparative study is presented for verification of the derivation and solution procedure. The nonlinear to linear frequency ratio is computed based on significant input parameters of porous core and carbon-nanotube-reinforced face sheets such as type of porosity, porosity coefficient, volume fraction, and type of reinforcement’s distribution.

5

Pozytywne efekty dodania nanorurek węglowych do zaprawy

Kostrzanowska-Siedlarz Aleksandra

Magazyn Autostrady

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2022

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Nr 3

24--28

PL

Celem badań przedstawionych w artykule jest poszukiwanie pozytywnych efektów dodania wielościennych nanorurek węglowych do zapraw podczas modyfikacji właściwości reologicznych, cech wytrzymałościowych oraz analiza bibliometryczna ujawniająca pozytywny wpływ nanorurek na kinetykę hydratacji.

EN

The paper presents research which aim is to search for the positive effects of adding multi-wall carbon nanotubes to mortar during the modification of rheological properties, strength properties and bibliometric analysis in order to look for the influence of nanotubes on the hydration kinetics.

6

Zawiesina nanorurek z surfaktantem, a właściwości reologiczne zapraw cementowych

Goldmann Eryk, Kostrzanowska-Siedlarz Aleksandra, Górski Marcin, Klemczak Barbara

Cement Wapno Beton

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2022

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R. 27, nr 4

275--284

PL

Dodatek nanomateriałów węglowych wpływa na szereg właściwości kompozytów cementowych. Pomimo wielu badań na temat właściwości stwardniałych materiałów cementowych, wpływ nanorurek węglowych [MWCNT, ang. Multiwall Carbon Nanotube] na właściwości reologiczne zapraw cementowych, wciąż nie jest wystarczająco opisany. Badania wykazały, że właściwości reologiczne zapraw z MWCNT, oznaczone Viskomatem NT, okazały się bardzo zależne od czasu sonikacji i ilości MWCNT. Wraz ze wzrostem czasu sonikacji zawiesiny z MWCNT i surfaktantem oraz wraz ze zmniejszeniem zawartości MWCNT płynność zaprawy jest większa, tym samym zmniejsza się zarówno granica płynięcia jak i lepkość plastyczna.

EN

The addition of carbon nanomaterials influences the variety of properties, of cementitious composites. Despite the multiple researches in the topic of properties of the hardened cement materials the influence of the Mutiwall Carbon Nanotubes [MWCNT] on rheological parameters of the cement mortars is not sufficiently described. Research shows that rheological properties of cement mortars with the MWCNTs, determined with the use of Viscometer NT, proved to be strongly dependent on the sonication time and amount of MWCNT, added. Increase of sonication time of MWCNT suspension with surfactant and decrease of amount of MWCNT caused increment in fluidity while yield stress parameter and plastic viscosity parameter decreased.

7

Dispersion mechanism-induced variations in microstructural and mechanical behavior of CNT-reinforced aluminum nanocomposites

Doğan Kemal, Özgün Muhammed Ihsan, Sübütay Halit, Salur Emin, Eker Yasin, Kuntoğlu Mustafa, Aslan Abdullah, Gupta Munish Kumar, Acarer Mustafa

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 1

art. no. e55, 2022

EN

The combination of powder metallurgy and ball milling method has been widely regarded as the most beneficial route for producing multi-walled carbon nanotubes (MWCNTs)-reinforced aluminum matrix composites. In this study, the effects of different milling times (1, 2, 4, and 8 h) on the structural, morphological, and crystallographic properties of MWCNTs-reinforced Al7075 composite powders were characterized by particle size analyzer, Raman spectroscopy, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and X-ray diffraction (XRD). After the morphological and structural characterization of the milled powders, the microstructural and mechanical properties of the hot-pressed composites were evaluated using an optical microscope, SEM, density, and Brinell hardness measurements. Considering milled powder characterization, the MWCNTs were gradually distributed and embedded within the matrix as the milling time increased. Milling for 8 h resulted in a minimum level of particle size (11 µm) with shortened and uniformly dispersed CNTs. Brinell hardness of the composite increased from 91 to 237 HB -a ⁓%160 after 8 h of milling. Such a remarkable increment in hardness could be attributed to several concurrent strengthening effects related to dispersion, solution, grain refinement, and Orowan looping mechanisms. However, relative density results revealed that the composite produced by 2 h milled powders exhibited the highest density (%99.96). The observed differences between hardness and density results were ascribed to powders’ deteriorated packing and sintering behavior due to an increment in the hardness of particles and variation in particle size range and morphology, which resulted from following different milling protocols.

8

Buckling analysis of composite conical shells reinforced by agglomerated functionally graded carbon nanotube

Eskandary K., Shishesaz Mohammad, Moradi Shapour

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 3

art. no. e132

EN

This study primary objective is to analyze the effect of agglomeration of carbon nanotubes on the buckling behavior of functionally graded carbon nanotube-reinforced composite conical shells (FG-CNTCS). Considering the first-order shear deformation theory, the differential equations of buckling behavior are obtained. Subsequently, the buckling load was derived utilizing Galerkin methods. A parametric study is established to consider the influence of characteristic parameters on the buckling behavior of the FG-CNTCS. The results reveal that agglomeration of CNTs substantially reduces the buckling load. Considering that, the effect of high volume fractions of carbon nanotubes on increasing buckling load is overly inconsiderable, it is suggested to use low volume fractions of nanoparticles in producing this type of nanocomposites, which reduces the probability of agglomeration phenomenon and also cut down the manufacturing costs.

9

Effect of Modified Carbon Nanotubes Epoxy on the Mechanical Properties of Concrete Reinforced with FRP Sheets

Kazemi Hamid, Heydari Mostafa, Bamoharam Fateme Farash

Civil and Environmental Engineering Reports

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2021

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Vol. 31, no. 3

177--196

EN

Today, using Fiber Reinforced Polymer (FRP) sheets is one of the conventional methods in retrofitting concrete structures. Some factors affecting FRP sheets proper performance include mechanical properties, surface specifications, connector’s material and connecting approach in concrete elements. Previous studies showed that FRP epoxy resin and its basic surface have a significant impact on the ultimate bearing capacity. In line with the development of nanotechnology in recent years, this paper presents an experimental study to show the effects of adding the best percentage of nano-carbons to adhesive resin and evaluate the ultimate axial, shear and bending strengths in concrete samples. The results show that using FRP with carbon nanotube reinforced resins will significantly increase stiffness and ductility by 100%; moreover, it shows an effective increase of almost 13% in axial and flexural strengths of specimens.

10

Electromagnetic Wave Absorbing Properties of Cotton Fabric with Carbon Nanotubes Coating

Zou Lihua, Shen Jiahui, Xu Zhenzhen, Ruan Fangtao, Qiu Yiping, Liu Zhi

Fibres & Textiles in Eastern Europe

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2020

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Vol. 28, no. 5 (143)

82--90

EN

In order to endow cotton fabric with the electromagnetic shielding property while preserving comfort and softness, carbon nanotubes (CNTs) were coated onto NaOH pretreated fabrics via a binder-free dip-coating approach. Scanning electron microscopy (SEM) and Infrared spectroscopy were utilised to investigate the surface morphology and modification of the CNT functionalised fabrics. The effects of the number of dip-coatings, the concentration of carbon nanotubes, and the impregnation temperature on electrical conductivity, electromagnetic (EM) shielding effectiveness (SE), and wave absorbing efficiency of cotton fabrics were evaluated, respectively. The SE value of the CNT functionalised cotton fabrics increased with the dip-coating time and reached 16.5 dB after CNT dip-coating ten times, which indicates that 97.76% of the electromagnetic wave was shielded. Meanwhile, by adding layers of stacking fabrics, the SE of CNT coated fabrics was further improved to 26.4 dB. The shielding mechanism was also studied by comparing its reflection and absorption behaviour, which demonstrates that 65.7% of the electromagnetic wave was absorbed.

PL

Aby nadać tkaninie bawełnianej właściwości ekranowania elektromagnetycznego przy jednoczesnym zachowaniu komfortu i miękkości, najpierw zastosowano obróbkę tkaniny z zastosowaniem NaOH, a następnie nałożono na nią powłokę z nanorurek węglowych (CNT). Za pomocą skaningowej mikroskopii elektronowej (SEM) i spektroskopii w podczerwieni zbadano morfologię powierzchni tkanin funkcjonalizowanych CNT. Oceniono wpływ liczby powłok zanurzeniowych, stężenia nanorurek węglowych i temperatury impregnacji na przewodność elektryczną, skuteczność ekranowania elektromagnetycznego (EM) (SE) oraz efektywność pochłaniania fal przez tkaniny bawełniane. Stwierdzono, że wartość SE funkcjonalizowanych tkanin bawełnianych CNT wzrastała wraz z czasem powlekania zanurzeniowego i osiągnęła 16.5 dB po dziesięciokrotnym powlekaniu zanurzeniowym CNT, co wskazało, że 97.76% fali elektromagnetycznej było ekranowane. Poprzez dodanie warstw tkanin, współczynnik SE tkanin powlekanych CNT został dodatkowo poprawiony do 26,4 dB. Zbadano również mechanizm ekranowania, porównując jego właściwości odbijania oraz pochłaniania i stwierdzono, że 65.7% fali elektromagnetycznej zostało zaabsorbowane.

11

Estimation of residual stress in air plasma sprayed MWCNT-reinforced 8YSZ-alumina composite coating

Thakare J. G., Mulik R. S., Mahapatra M. M.

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 4

1--15

EN

Thermal barrier coating (TBC) with Al2O3 and 8YSZ as topcoat constituents has been developed. The commercially available 8YSZ (80% wt.), Al2O3 (17 and 19% wt.) and multiwall carbon nanotubes (MWCNT) (3% and 1% wt.) were plasma sprayed to produce composite coatings. A stress relaxation technique using a slow-speed diamond cutter has been used to relax the strain and determine the through-thickness residual stress in the coatings. A 3D finite element model was developed, the model was experimentally validated, and the model was used to establish a relationship between applied stress and relaxed strain. The addition of alumina increased the compressive residual stress on the surface of the coating by 42%, the addition of 1% MWCNT had a negligible effect on the residual stress on the coating surface. The further addition of MWCNT (3% wt.) resulted in tensile residual stress in the coating as a result of MWCNT agglomeration.

12

Properties of flame-powder sprayed aluminum coatings reinforced with particles of carbonaceous materials

Czupryński Artur

Welding Technology Review

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2019

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R. 91, nr 4

17--30

EN

The article presents the results of research on tribological properties of aluminum coatings, reinforced with particles of carbon nanotubes Nanocyl NC 7000 in quantities of 0.5 wt.% and 1 wt.% as well as carburite (elemental carbon) in an amount of 0.5 wt.%, flame-powder sprayed on a non-alloy structural steel grade S235J0 according to EN 10027-1. The coating properties were assessed based on macro and microscopic metallographic examinations, chemical composition tests, microhardness measurements and abrasion and erosive wear resistance tests. The obtained results were compared with the results obtained for samples with coatings made of aluminum powder - EN AW 1000 series.

PL

W artykule przedstawiono wyniki badań dotyczących właściwości tribologicznych powłok aluminiowych, wzmacnianych cząstkami materiałów węglowych w postaci nanorurek Nanocyl NC 7000 w ilości 0,5% wag. i 1% wag. oraz karburytu (węgla pierwiastkowego) w ilości 0,5% wag., natryskiwanych płomieniowo proszkowo (PFS) na podłoże z niestopowej stali konstrukcyjnej gatunku S235JO wg EN 10027-1. Oceny właściwości powłok dokonano w oparciu o badania metalograficzne makro- i mikroskopowe, badania składu chemicznego, pomiar twardości oraz badania odporności na zużycie ścierne i erozyjne. Otrzymane wyniki porównano z wynikami otrzymanymi dla próbek z powłokami wykonanymi proszkiem aluminium seria EN AW 1000.

13

Condition monitoring of crack extension in the reinforced adhesive joint by carbon nanotubes

Sam-Daliri Omid, Farahani Mohammadreza, Araei Alireza

Welding Technology Review

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2019

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R. 91, nr 12

7--15

EN

Carbon nanotubes (CNT) are ideally suited to be employed for damage sensing in fiber reinforced composite structures. In this work, the capability of CNTs for crack extension of a single lap Al-Al adhesive joints (SLJ) under shear load is studied using electrical resistance change. Different weight percent of CNT are added to epoxy adhesive. Epoxy adhesive with high concentration of CNT is obtained during shear loading to have the maximum strength and provide the best sensory properties. To provide a more concise evaluation of the crack extension in the adhesive layer under shear load, artificial defects are embedded into the SLJ specimens. The effects of square and circular defects with two different sizes on the crack extension in the adhesive layer are evaluated. The results showed that the maximum relative resistance change has occurred by 220% when the microcracks are initiated and accordingly developed from the nanoadhesive and changed its direction from the Square defect boundary. Additionally, in comparison with interface fracture in defective adhesive joint, when a part of crack grows through the adhesive layer, the resistance change showed higher values.

PL

Nanorurki węglowe (ang. Carbon Nanotubes CNT) nadają się do zastosowania w wykrywaniu uszkodzeń w strukturach kompozytowych wzmacnianych włóknami. W pracy tej badana jest zdolność CNT do propagacji pęknięć w jednozakładkowych połączeniach klejowych Al-Al (SLJ) pod obciążeniem ścinającym przy użyciu zmiany oporu elektrycznego. Do kleju epoksydowego dodawano CNT o różnym procentowym stężeniu wagowym. Klej epoksydowy o wysokim stężeniu CNT uzyskuje się podczas obciążenia ścinającego, aby uzyskać maksymalną wytrzymałość i zapewnić najlepsze właściwości sensoryczne. Aby zapewnić bardziej zwięzłą ocenę propagacji pęknięcia w warstwie klejowej pod obciążeniem ścinającym, sztuczne wady zostały osadzone w próbkach SLJ. Ocenie poddano wpływ kwadratowych i kołowych wad o dwóch różnych rozmiarach na propagację pęknięcia w warstwie klejowej. Wyniki wskazują, że maksymalna względna zmiana rezystancji wyniosła 220%, kiedy mikropęknięcia są inicjowane i odpowiednio rozwijane z nanokleju i zmieniają swój kierunek od granicy kwadratowego defektu. Dodatkowo, w porównaniu z pęknięciem powierzchni styku w uszkodzonym połączeniu klejowym, gdy część pęknięcia rośnie przez warstwę kleju, zmiana rezystancji wykazała wyższe wartości.

14

Wykorzystanie emiterów polowych z nanorurek węglowych (CNT) w miniaturyzacji lamp rentgenowskich

Pesce Martin, Wang Xiaohui, Rowland Peter

Inżynier i Fizyk Medyczny

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2019

|

Vol. 8, nr 2

105--107

PL

Promieniowanie rentgenowskie (promienie X) jest wytwarzane pod wpływem uderzeń wiązki przyspieszonych elektronów w anodę, np. wolframową, umieszczoną w lampie próżniowej. Lampy rentegenowskie używają jako źródła elektronów żarzone włókna katody, począwszy od wynalezienia lampy przez W. Roentgena w 1895 roku.

15

On the development and studies of nano- and micro-fiber hybridized strain hardened cementitious composite

Sindu B. S., Sasmal Saptarshi

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 2

348--359

EN

In this study, strain hardened cementitious composite is developed by systematically incorporating fibers of two different length scales, viz., PVA fibers (micro-fibers) and CNTs (nano-fibers) to improve the load transfer and crack formation mechanism at their corresponding scales. At first, the influence of individual fibers on the tension associated (axial tension-, fracture- and flexure-) properties is investigated. Then, the composite is developed using hybrid fibers with appropriate dosage to cater the desired performance. The tensile strength, stiffness, strain carrying capacity and fracture energy of the developed composite is found to be improved by almost 2 times, 3 times, 220 times and 130 times respectively to that of the original cement composite. The outstanding performance of the developed composite is resulted from the effective crack bridging and preferred load transfer in micro-scale due to incorporation of (a meagre amount of) hetero fibers of distinctly different length scales. In order to investigate the fracture and crack propagation phenomenon of the developed cementitious composite, Digital Image Correlation (DIC) technique is also employed. The findings of this study will lead towards development of multi-performance cementitious composite (MPCC) by tailoring the material to attain the desired level of strength, stiffness and ductility.

16

Mechanical, tribological and electrical properties of Cu-CNT composites fabricated by flake powder metallurgy method

Akbarpour M. R., Alipour S, Farvizi M., Kim H. S.

Archives of Civil and Mechanical Engineering

|

2019

|

Vol. 19, no. 3

694--706

EN

Cu-CNT composites were fabricated by a flake powder metallurgy method, and their microhardness, electrical conductivity, frictional and wear properties were investigated. Homogenous distribution of CNTs in fine-grained Cu matrix was obtained using this process. Microhardness increased with the addition of CNT vol% up to 8% to the Cu matrix, while the conductivity decreased to 79.2 IACS %. Results showed that CNTs play a major role in improving wear resistance by forming a CNT-rich film that acts as a solid lubricant layer. In the synthesized composites, Cu- 4 vol% CNT composite exhibited the best wear and friction properties. The dominant wear mechanisms for the Cu-CNT composites were plastic deformation, abrasion, and flake formation-spalling. Also, a newly modified correlation was proposed for the theoretical calculation of the friction coefficient of Cu-CNT composites consisting agglomerated CNTs.

17

Wpływ stopowania laserowego z użyciem nanorurek węglowych stopu Ti13Nb13Zr do zastosowań biomedycznych na jego wybrane własności mechaniczne

Rogala-Wielgus D., Majkowska-Marzec B., Bartmański M.

Przegląd Spawalnictwa

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2018

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R. 90, nr 7

18--23

PL

Do eksperymentu użyto stopu tytanu Ti13Nb13Zr, który ze względu na swój skład chemiczny i właściwości mechaniczne stanowi materiał do zastosowań w inżynierii medycznej. Celem pracy była ocena wpływu stopowania laserowego stopu Ti13Nb13Zr z powłoką z wielościennych nanorurek węglowych na jego właściwości mechaniczne (chropowatość, nanotwardość, moduł Younga). Do wytworzenia powłoki węglowej wykorzystano metodę osadzania elektroforetycznego (EDP). Modyfikację laserową przeprowadzono przy użyciu impulsowego lasera Nd:YAG. Zastosowano moc impulsu 800 W i czas impulsu 0,5 ms oraz 1 ms. Właściwości mechaniczne zmierzono za pomocą nanoindentera, zaś chropowatość z użyciem mikroskopu sił atomowych (AFM). Zastosowanie powłoki z wielościennych nanorurek węglowych do stopowania laserowego stopu Ti13Nb13Zr oraz odpowiedni dobór parametrów procesu pozwoliły na podwyższenie właściwości mechanicznych (nanotwardość wzrosła ponad dwukrotnie) w stosunku do własności materiału rodzimego, nastąpiło również ujednolicenie właściwości w obrębie badanej powierzchni.

EN

The titanium alloy Ti13Nb13Zr was used as a substrate, because of its chemical composition and good mechanical properties in application of tissue engineering. The aim of the wark was the assessment of the influence of laser alloying of Ti13Nb13Zr coated with multi-walled carbon nanotubes for mechanical properties (roughness, nanohardness, Young modulus). Electrophoretic deposition (EOP) method was used to prepare carbon coating. Laser modification was carried out with Nd:YAG laser in pulsed mode operating system. The power of the impulse was 800 Wand the time 0,5 ms and 1 ms. Mechanical properties were checked with nanoindenter and roughness of the surface with Atomic Force Microscope (AFM). The improvement of mechanical properties (the nanohardness increases more than twice) and its homogeneity within tested area (in the comparisan to the native material) was seen after implementation of carbon nanotube coating with appropriate parameters of the process.

18

Zastosowanie nanorurek węglowych w zaprawach naprawczych

Błonka A., Kowal A., Ubysz A.

Materiały Budowlane

|

2018

|

nr 8

88--90

PL

W artykule przedstawiono wyniki prowadzonych na świecie badań nad nanorurkami węglowymi, a ściślej nad ich potencjalnym zastosowaniem jako nanododatku do zapraw naprawczych w konstrukcjach żelbetowych. W badaniach wstępnych określono najlepszy stosunek masowy włókien do cementu pod względem wytrzymałości na ściskanie i rozciąganie przy zginaniu. Wyniki badań wstępnych (optymalna zawartość nanorurek) wykorzystano przy badaniu przyczepności zaprawy kompozytowej do istniejącej konstrukcji. Wyniki obydwu badań pozwoliły określić użyteczność stosowania nanowłókien węglowych w kompozytowych zaprawach naprawczych.

EN

In the article the results of conducting researches from the world about carbon nanotubes, precisely their applicability as nanosuplement for the concrete repair material for the reinforced concrete structures, were described. In the introducing researches the best (in terms of compressive and flexural strength) range of carbon nanotubes proportion in terms of cement weight was specified. The results of introducing researches (optimal carbone nanotubes’ dosage) were used in research about measuring the repair materials with carbon nanotubes bonding with existing concrete structures. The results of both researches provide to determine the usability of carbon nanotubes for concrete repair materials.

19

Microwave and spark plasma sintering of carbon nanotube and graphene reinforced aluminum matrix composite

Ghasali E., Sangpour P., Jama A., Rajaei H., Shirvanimoghaddam K., Ebadzadeh T.

Archives of Civil and Mechanical Engineering

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2018

|

Vol. 18, no. 4

1042--1054

EN

Graphene and carbon nanotube due to their outstanding mechanical performance were used as reinforcement in aluminum (Al) based composite through spark plasma sintering (SPS), microwave (MW) and conventional techniques. The initial compositions of Al-1 wt% CNT, Al-1 wt% GNP and Al-1 wt% CNT–1 wt% GNP were mixed by a high energy ultrasonic device and mixer mill to achieve homogenous dispersion. The SPS, MW and conventional processes were conducted at almost 450, 600 and 700 °C, respectively. The maximum relative density (99.7 ± 0.2% of theoretical density) and bending strength (337 ± 11 MPa) obtained by SPS, while maximum microhardness of 221 ± 11 Vickers achieved by microwave for Al-1 wt% CNT–1 wt% GNP hybrid composite. X-ray diffraction (XRD) examinations identified Al as the only dominant phase accompanied by very low intensity peaks of Al4C3. Field emission scanning electron microscopy (FESEM) micrographs demonstrated uniform distribution of GNP as well as CNT reinforcement in spark plasma sintered samples.

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An innovative system for piston engine combustion with laser-induced ignition of the hydrocarbon fuel consisting carbon nanotubes

Kałużny J., Merkisz J., Gallas D., Runka T., Kozak M., Pielecha I.

Combustion Engines

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2017

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R. 56, nr 1

3--14

EN

The article proposes the concept of a new piston engine combustion system that is designed to meet future-oriented ecological requirements. The concept is to use ethanol as a fuel, in which a slurry of carbon nanotubes would be formed, which are characterized by the ability to ignite using a pulse of laser light fed into the combustion chamber. Modifying the shape of the light beam that penetrates the combustion chamber would allow to control the position and the size of the area in which the ignition of fuel would occur. The originality of the concept is to combine the latest achievements in the field of nanotechnology in the construction of lasers and the production of biofuels, so as to contribute to improving the environmental performance of engines using the existing synergies. The article discusses the prospects for the use of bioethanol as a fuel with zero carbon balance, a critical review of related research on light pulse initiated ignition of hydrocarbon fuels from carbon nanotubes was presented, and a review of studies of laser ignition for conventional fuels. The results of studies of carbon nanotubes suspensions in a variety of fuels conducted by the authors in order to seek solutions for the stable dispersions formation, that are resistant to nanotube agglomeration and sedimentation. The summary indicates directions for further research highlighting the importance of environmental impact.