Investigation and Optimization of the Technological and Functional Performance of the Ventilation Mill in the Thermal Power Plant Kostolac B

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Investigation and Optimization of the Technological and Functional Performance of the Ventilation Mill in the Thermal Power Plant Kostolac B (en)
Истраживање и оптимизација технолошких и функционалних перформанси вентилационог млина термоелектране Костолац Б (sr)
Istraživanje i optimizacija tehnoloških i funkcionalnih performansi ventilacionog mlina termoelektrane Kostolac B (sr_RS)
Authors

Publications

Influence of secondary phases in A356 MMCs on their mechanical properties at macro- and nanoscale

Vencl, Aleksandar; Bobić, Ilija; Stanković, Miloš; Hvizdoš, Pavol; Bobić, Biljana M.; Stojanović, Blaža; Franek, Friedrich

(2020)

TY  - JOUR
AU  - Vencl, Aleksandar
AU  - Bobić, Ilija
AU  - Stanković, Miloš
AU  - Hvizdoš, Pavol
AU  - Bobić, Biljana M.
AU  - Stojanović, Blaža
AU  - Franek, Friedrich
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8829
AB  - Metal matrix composites are very inhomogeneous materials, and their properties depend on various parameters (production process, constituents, their interfaces, etc.). The influence of SiC microparticles (40 mu m) reinforcement and graphite macroparticles (200-800 mu m) addition on the mechanical properties of Al-Si A356 alloy, produced by compocasting, has been assessed using macro- and nanoscale measurements of hardness and modulus of elasticity. The Al makes over 90 wt% of the A356 alloy, so the nanoscale measurements were performed on different alpha phase regions on each material (core of alpha phase, eutectic alpha phase, and alpha phase near the phase boundaries alpha phase/secondary phases). The results showed that there is no direct correlation between mechanical properties on macro- and nanoscale. The nanoscale results also showed that the secondary phases (SiC and graphite particles) can have significant effect on the mechanical properties on the atomic level, i.e. in the alpha phase regions very close to the secondary phases.
T2  - Journal of the Brazilian Society of Mechanical Sciences and Engineering
T1  - Influence of secondary phases in A356 MMCs on their mechanical properties at macro- and nanoscale
VL  - 42
IS  - 3
SP  - 115
DO  - 10.1007/s40430-020-2197-6
ER  - 
@article{
author = "Vencl, Aleksandar and Bobić, Ilija and Stanković, Miloš and Hvizdoš, Pavol and Bobić, Biljana M. and Stojanović, Blaža and Franek, Friedrich",
year = "2020",
abstract = "Metal matrix composites are very inhomogeneous materials, and their properties depend on various parameters (production process, constituents, their interfaces, etc.). The influence of SiC microparticles (40 mu m) reinforcement and graphite macroparticles (200-800 mu m) addition on the mechanical properties of Al-Si A356 alloy, produced by compocasting, has been assessed using macro- and nanoscale measurements of hardness and modulus of elasticity. The Al makes over 90 wt% of the A356 alloy, so the nanoscale measurements were performed on different alpha phase regions on each material (core of alpha phase, eutectic alpha phase, and alpha phase near the phase boundaries alpha phase/secondary phases). The results showed that there is no direct correlation between mechanical properties on macro- and nanoscale. The nanoscale results also showed that the secondary phases (SiC and graphite particles) can have significant effect on the mechanical properties on the atomic level, i.e. in the alpha phase regions very close to the secondary phases.",
journal = "Journal of the Brazilian Society of Mechanical Sciences and Engineering",
title = "Influence of secondary phases in A356 MMCs on their mechanical properties at macro- and nanoscale",
volume = "42",
number = "3",
pages = "115",
doi = "10.1007/s40430-020-2197-6"
}
Vencl, A., Bobić, I., Stanković, M., Hvizdoš, P., Bobić, B. M., Stojanović, B.,& Franek, F.. (2020). Influence of secondary phases in A356 MMCs on their mechanical properties at macro- and nanoscale. in Journal of the Brazilian Society of Mechanical Sciences and Engineering, 42(3), 115.
https://doi.org/10.1007/s40430-020-2197-6
Vencl A, Bobić I, Stanković M, Hvizdoš P, Bobić BM, Stojanović B, Franek F. Influence of secondary phases in A356 MMCs on their mechanical properties at macro- and nanoscale. in Journal of the Brazilian Society of Mechanical Sciences and Engineering. 2020;42(3):115.
doi:10.1007/s40430-020-2197-6 .
Vencl, Aleksandar, Bobić, Ilija, Stanković, Miloš, Hvizdoš, Pavol, Bobić, Biljana M., Stojanović, Blaža, Franek, Friedrich, "Influence of secondary phases in A356 MMCs on their mechanical properties at macro- and nanoscale" in Journal of the Brazilian Society of Mechanical Sciences and Engineering, 42, no. 3 (2020):115,
https://doi.org/10.1007/s40430-020-2197-6 . .
7
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Erosive wear properties of ZA-27 alloy-based nanocomposites: Influence of type, amount, and size of nanoparticle reinforcements

Vencl, Aleksandar; Bobić, Ilija; Bobić, Biljana M.; Jakimovska, Kristina; Svoboda, Petr; Kandeva, Mara

(2019)

TY  - JOUR
AU  - Vencl, Aleksandar
AU  - Bobić, Ilija
AU  - Bobić, Biljana M.
AU  - Jakimovska, Kristina
AU  - Svoboda, Petr
AU  - Kandeva, Mara
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8357
AB  - Metal matrix nanocomposites (MMnCs) comprise a metal matrix filled with nanosized reinforcements with physical and mechanical properties that are very different from those of the matrix. In ZA-27 alloy-based nanocomposites, the metal matrix provides ductility and toughness, while usually used ceramic reinforcements give high strength and hardness. Tested ZA-27 alloy-based nanocomposites, reinforced with different types (SiC and Al2O3), amounts (0.2 wt.%, 0.3 wt.%, and 0.5 wt.%) and sizes (25 nm, 50 nm, and 100 nm) of nanoparticles were produced through the compocasting process with mechanical alloying pre-processing (ball milling). It was previously shown that the presence of nanoparticles in ZA-27 alloy-based nanocomposites led to the formation of a finer structure in the nanocomposites matrix and an improvement in the basic mechanical properties (hardness and compressive yield strength) through the enhanced dislocation density strengthening mechanism. Solid particle erosive wear testing demonstrated that these improvements were followed with an increase in the erosive wear resistance of tested nanocomposites, as well. Additionally, by analyzing the influences of type, amount, and size of nanoparticles on the erosive wear resistance of nanocomposites, it was demonstrated that there is an optimal amount of nanoparticles, which in our case is 0.3 wt.%, and that the presence of SiC nanoparticles and smaller nanoparticles in nanocomposites had more beneficial influence on erosive wear resistance. © 2018, The author(s).
T2  - Friction
T1  - Erosive wear properties of ZA-27 alloy-based nanocomposites: Influence of type, amount, and size of nanoparticle reinforcements
VL  - 7
IS  - 4
SP  - 340
EP  - 350
DO  - 10.1007/s40544-018-0222-x
ER  - 
@article{
author = "Vencl, Aleksandar and Bobić, Ilija and Bobić, Biljana M. and Jakimovska, Kristina and Svoboda, Petr and Kandeva, Mara",
year = "2019",
abstract = "Metal matrix nanocomposites (MMnCs) comprise a metal matrix filled with nanosized reinforcements with physical and mechanical properties that are very different from those of the matrix. In ZA-27 alloy-based nanocomposites, the metal matrix provides ductility and toughness, while usually used ceramic reinforcements give high strength and hardness. Tested ZA-27 alloy-based nanocomposites, reinforced with different types (SiC and Al2O3), amounts (0.2 wt.%, 0.3 wt.%, and 0.5 wt.%) and sizes (25 nm, 50 nm, and 100 nm) of nanoparticles were produced through the compocasting process with mechanical alloying pre-processing (ball milling). It was previously shown that the presence of nanoparticles in ZA-27 alloy-based nanocomposites led to the formation of a finer structure in the nanocomposites matrix and an improvement in the basic mechanical properties (hardness and compressive yield strength) through the enhanced dislocation density strengthening mechanism. Solid particle erosive wear testing demonstrated that these improvements were followed with an increase in the erosive wear resistance of tested nanocomposites, as well. Additionally, by analyzing the influences of type, amount, and size of nanoparticles on the erosive wear resistance of nanocomposites, it was demonstrated that there is an optimal amount of nanoparticles, which in our case is 0.3 wt.%, and that the presence of SiC nanoparticles and smaller nanoparticles in nanocomposites had more beneficial influence on erosive wear resistance. © 2018, The author(s).",
journal = "Friction",
title = "Erosive wear properties of ZA-27 alloy-based nanocomposites: Influence of type, amount, and size of nanoparticle reinforcements",
volume = "7",
number = "4",
pages = "340-350",
doi = "10.1007/s40544-018-0222-x"
}
Vencl, A., Bobić, I., Bobić, B. M., Jakimovska, K., Svoboda, P.,& Kandeva, M.. (2019). Erosive wear properties of ZA-27 alloy-based nanocomposites: Influence of type, amount, and size of nanoparticle reinforcements. in Friction, 7(4), 340-350.
https://doi.org/10.1007/s40544-018-0222-x
Vencl A, Bobić I, Bobić BM, Jakimovska K, Svoboda P, Kandeva M. Erosive wear properties of ZA-27 alloy-based nanocomposites: Influence of type, amount, and size of nanoparticle reinforcements. in Friction. 2019;7(4):340-350.
doi:10.1007/s40544-018-0222-x .
Vencl, Aleksandar, Bobić, Ilija, Bobić, Biljana M., Jakimovska, Kristina, Svoboda, Petr, Kandeva, Mara, "Erosive wear properties of ZA-27 alloy-based nanocomposites: Influence of type, amount, and size of nanoparticle reinforcements" in Friction, 7, no. 4 (2019):340-350,
https://doi.org/10.1007/s40544-018-0222-x . .
1
11
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Parametric optimization of the aluminium nanocomposites wear rate

Veličković, Sandra; Stojanović, Blaža; Babić, Miroslav; Vencl, Aleksandar; Bobić, Ilija; Vadaszne Bognar, Gabriella; Vučetić, Filip

(2019)

TY  - JOUR
AU  - Veličković, Sandra
AU  - Stojanović, Blaža
AU  - Babić, Miroslav
AU  - Vencl, Aleksandar
AU  - Bobić, Ilija
AU  - Vadaszne Bognar, Gabriella
AU  - Vučetić, Filip
PY  - 2019
UR  - http://link.springer.com/10.1007/s40430-018-1531-8
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8077
AB  - The optimization of wear rate of the nanocomposites with A356 aluminium alloy matrix, reinforced with silicon carbide nanoparticles, was performed through the analysis of the following influences: wt% of the reinforcement, normal load and sliding speed. The nanocomposites were produced by the compocasting process with mechanical alloying preprocessing (ball milling). Three different amounts of SiC nanoparticles, with the same average size of 50 nm, were used as reinforcement, i.e. 0.2, 0.3 and 0.5 wt%. Tribological tests were performed on block-on-disc tribometer (line contact) under lubricated sliding conditions, at two sliding speeds (0.25 and 1 m/s), two normal loads (40 and 100 N) and at sliding distance of 1000 m. Analysis of variance (ANOVA) was applied to determine the influence of different parameters on wear value of tested nanocomposites. It was noticed from ANOVA analysis that normal load, with 33.39%, is the most significant factor affecting the wear rate of nanocomposites. The amount of reinforcement, with 28.90%, also has a significant influence on the wear rate, while the influence of sliding speed, with 23.82%, is smaller. It was found that the prediction of wear rate, by using regression model and Taguchi analysis, were close to the experimental values. © The Brazilian Society of Mechanical Sciences and Engineering 2018.
T2  - Journal of the Brazilian Society of Mechanical Sciences and Engineering
T1  - Parametric optimization of the aluminium nanocomposites wear rate
VL  - 41
IS  - 1
SP  - 19
DO  - 10.1007/s40430-018-1531-8
ER  - 
@article{
author = "Veličković, Sandra and Stojanović, Blaža and Babić, Miroslav and Vencl, Aleksandar and Bobić, Ilija and Vadaszne Bognar, Gabriella and Vučetić, Filip",
year = "2019",
abstract = "The optimization of wear rate of the nanocomposites with A356 aluminium alloy matrix, reinforced with silicon carbide nanoparticles, was performed through the analysis of the following influences: wt% of the reinforcement, normal load and sliding speed. The nanocomposites were produced by the compocasting process with mechanical alloying preprocessing (ball milling). Three different amounts of SiC nanoparticles, with the same average size of 50 nm, were used as reinforcement, i.e. 0.2, 0.3 and 0.5 wt%. Tribological tests were performed on block-on-disc tribometer (line contact) under lubricated sliding conditions, at two sliding speeds (0.25 and 1 m/s), two normal loads (40 and 100 N) and at sliding distance of 1000 m. Analysis of variance (ANOVA) was applied to determine the influence of different parameters on wear value of tested nanocomposites. It was noticed from ANOVA analysis that normal load, with 33.39%, is the most significant factor affecting the wear rate of nanocomposites. The amount of reinforcement, with 28.90%, also has a significant influence on the wear rate, while the influence of sliding speed, with 23.82%, is smaller. It was found that the prediction of wear rate, by using regression model and Taguchi analysis, were close to the experimental values. © The Brazilian Society of Mechanical Sciences and Engineering 2018.",
journal = "Journal of the Brazilian Society of Mechanical Sciences and Engineering",
title = "Parametric optimization of the aluminium nanocomposites wear rate",
volume = "41",
number = "1",
pages = "19",
doi = "10.1007/s40430-018-1531-8"
}
Veličković, S., Stojanović, B., Babić, M., Vencl, A., Bobić, I., Vadaszne Bognar, G.,& Vučetić, F.. (2019). Parametric optimization of the aluminium nanocomposites wear rate. in Journal of the Brazilian Society of Mechanical Sciences and Engineering, 41(1), 19.
https://doi.org/10.1007/s40430-018-1531-8
Veličković S, Stojanović B, Babić M, Vencl A, Bobić I, Vadaszne Bognar G, Vučetić F. Parametric optimization of the aluminium nanocomposites wear rate. in Journal of the Brazilian Society of Mechanical Sciences and Engineering. 2019;41(1):19.
doi:10.1007/s40430-018-1531-8 .
Veličković, Sandra, Stojanović, Blaža, Babić, Miroslav, Vencl, Aleksandar, Bobić, Ilija, Vadaszne Bognar, Gabriella, Vučetić, Filip, "Parametric optimization of the aluminium nanocomposites wear rate" in Journal of the Brazilian Society of Mechanical Sciences and Engineering, 41, no. 1 (2019):19,
https://doi.org/10.1007/s40430-018-1531-8 . .
24
11
26

Tribological characterisation in dry sliding conditions of compocasted hybrid A356/SiCp/Grp composites with graphite macroparticles

Vencl, Aleksandar; Vučetić, Filip; Bobić, Biljana M.; Pitel, Ján; Bobić, Ilija

(2019)

TY  - JOUR
AU  - Vencl, Aleksandar
AU  - Vučetić, Filip
AU  - Bobić, Biljana M.
AU  - Pitel, Ján
AU  - Bobić, Ilija
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8448
AB  - The influence of SiC microparticles reinforcement and graphite macroparticles addition on the friction and wear characteristics of A356 Al-Si alloys, produced by compocasting, has been assessed using a pin-on-disc tribometer. The incorporation of SiC reinforcement increased the coefficient of friction and reduced the wear. The addition of graphite did not reduce the coefficient of friction. In the case of hybrid composite with 1 wt% graphite, wear was more or less the same as with SiC reinforced composite, while in the case of hybrid composite with 3 wt% graphite, wear was further reduced. On the worn surfaces of hybrid composites, the presence of the discontinuous mixed surface layer, containing graphite and transferred counter-body material, was noticed. © 2018, Springer-Verlag London Ltd., part of Springer Nature.
T2  - The International Journal of Advanced Manufacturing Technology
T1  - Tribological characterisation in dry sliding conditions of compocasted hybrid A356/SiCp/Grp composites with graphite macroparticles
VL  - 100
IS  - 9-12
SP  - 2135
EP  - 2146
DO  - 10.1007/s00170-018-2866-0
ER  - 
@article{
author = "Vencl, Aleksandar and Vučetić, Filip and Bobić, Biljana M. and Pitel, Ján and Bobić, Ilija",
year = "2019",
abstract = "The influence of SiC microparticles reinforcement and graphite macroparticles addition on the friction and wear characteristics of A356 Al-Si alloys, produced by compocasting, has been assessed using a pin-on-disc tribometer. The incorporation of SiC reinforcement increased the coefficient of friction and reduced the wear. The addition of graphite did not reduce the coefficient of friction. In the case of hybrid composite with 1 wt% graphite, wear was more or less the same as with SiC reinforced composite, while in the case of hybrid composite with 3 wt% graphite, wear was further reduced. On the worn surfaces of hybrid composites, the presence of the discontinuous mixed surface layer, containing graphite and transferred counter-body material, was noticed. © 2018, Springer-Verlag London Ltd., part of Springer Nature.",
journal = "The International Journal of Advanced Manufacturing Technology",
title = "Tribological characterisation in dry sliding conditions of compocasted hybrid A356/SiCp/Grp composites with graphite macroparticles",
volume = "100",
number = "9-12",
pages = "2135-2146",
doi = "10.1007/s00170-018-2866-0"
}
Vencl, A., Vučetić, F., Bobić, B. M., Pitel, J.,& Bobić, I.. (2019). Tribological characterisation in dry sliding conditions of compocasted hybrid A356/SiCp/Grp composites with graphite macroparticles. in The International Journal of Advanced Manufacturing Technology, 100(9-12), 2135-2146.
https://doi.org/10.1007/s00170-018-2866-0
Vencl A, Vučetić F, Bobić BM, Pitel J, Bobić I. Tribological characterisation in dry sliding conditions of compocasted hybrid A356/SiCp/Grp composites with graphite macroparticles. in The International Journal of Advanced Manufacturing Technology. 2019;100(9-12):2135-2146.
doi:10.1007/s00170-018-2866-0 .
Vencl, Aleksandar, Vučetić, Filip, Bobić, Biljana M., Pitel, Ján, Bobić, Ilija, "Tribological characterisation in dry sliding conditions of compocasted hybrid A356/SiCp/Grp composites with graphite macroparticles" in The International Journal of Advanced Manufacturing Technology, 100, no. 9-12 (2019):2135-2146,
https://doi.org/10.1007/s00170-018-2866-0 . .
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Experimental optimisation of the tribological behaviour of Al/SiC/Gr hybrid composites based on Taguchi’s method and artificial neural network

Stojanović, Blaža; Vencl, Aleksandar; Bobić, Ilija; Miladinović, Slavica; Skerlić, Jasmina

(2018)

TY  - JOUR
AU  - Stojanović, Blaža
AU  - Vencl, Aleksandar
AU  - Bobić, Ilija
AU  - Miladinović, Slavica
AU  - Skerlić, Jasmina
PY  - 2018
UR  - http://link.springer.com/10.1007/s40430-018-1237-y
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7710
AB  - This paper presents the investigation of tribological behaviour of aluminium hybrid composites with Al–Si alloy A356 matrix, reinforced with 10 wt% silicon carbide and 0, 1 and 3 wt% graphite (Gr) with the application of Taguchi’s method. Tribological investigations were realized on block-on-disc tribometer under lubricated sliding conditions, at three sliding speeds (0.25, 0.5 and 1 m/s), three normal loads (40, 80 and 120 N) and at sliding distance of 2400 m. Wear rate and coefficient of friction were measured within the research. Analysis of the results was conducted using ANOVA technique, and it showed that the smallest values of wear and friction are observed for hybrid composite containing 3 wt% Gr. The prediction of wear rate and coefficient of friction was performed with the use of artificial neural network (ANN). After training of the ANN, the regression coefficient was obtained and it was equal to 0.98905 for the network with architecture 3-20-30-2.
T2  - Journal of the Brazilian Society of Mechanical Sciences and Engineering
T1  - Experimental optimisation of the tribological behaviour of Al/SiC/Gr hybrid composites based on Taguchi’s method and artificial neural network
VL  - 40
IS  - 6
SP  - 311
DO  - 10.1007/s40430-018-1237-y
ER  - 
@article{
author = "Stojanović, Blaža and Vencl, Aleksandar and Bobić, Ilija and Miladinović, Slavica and Skerlić, Jasmina",
year = "2018",
abstract = "This paper presents the investigation of tribological behaviour of aluminium hybrid composites with Al–Si alloy A356 matrix, reinforced with 10 wt% silicon carbide and 0, 1 and 3 wt% graphite (Gr) with the application of Taguchi’s method. Tribological investigations were realized on block-on-disc tribometer under lubricated sliding conditions, at three sliding speeds (0.25, 0.5 and 1 m/s), three normal loads (40, 80 and 120 N) and at sliding distance of 2400 m. Wear rate and coefficient of friction were measured within the research. Analysis of the results was conducted using ANOVA technique, and it showed that the smallest values of wear and friction are observed for hybrid composite containing 3 wt% Gr. The prediction of wear rate and coefficient of friction was performed with the use of artificial neural network (ANN). After training of the ANN, the regression coefficient was obtained and it was equal to 0.98905 for the network with architecture 3-20-30-2.",
journal = "Journal of the Brazilian Society of Mechanical Sciences and Engineering",
title = "Experimental optimisation of the tribological behaviour of Al/SiC/Gr hybrid composites based on Taguchi’s method and artificial neural network",
volume = "40",
number = "6",
pages = "311",
doi = "10.1007/s40430-018-1237-y"
}
Stojanović, B., Vencl, A., Bobić, I., Miladinović, S.,& Skerlić, J.. (2018). Experimental optimisation of the tribological behaviour of Al/SiC/Gr hybrid composites based on Taguchi’s method and artificial neural network. in Journal of the Brazilian Society of Mechanical Sciences and Engineering, 40(6), 311.
https://doi.org/10.1007/s40430-018-1237-y
Stojanović B, Vencl A, Bobić I, Miladinović S, Skerlić J. Experimental optimisation of the tribological behaviour of Al/SiC/Gr hybrid composites based on Taguchi’s method and artificial neural network. in Journal of the Brazilian Society of Mechanical Sciences and Engineering. 2018;40(6):311.
doi:10.1007/s40430-018-1237-y .
Stojanović, Blaža, Vencl, Aleksandar, Bobić, Ilija, Miladinović, Slavica, Skerlić, Jasmina, "Experimental optimisation of the tribological behaviour of Al/SiC/Gr hybrid composites based on Taguchi’s method and artificial neural network" in Journal of the Brazilian Society of Mechanical Sciences and Engineering, 40, no. 6 (2018):311,
https://doi.org/10.1007/s40430-018-1237-y . .
41
13
39

Studies of the Iranian medieval ceramics surface modified by pulsed tea CO2 and Nd:YAG lasers

Polic, S.; Ristic, S.; Stašić, Jelena; Trtica, Milan; Radojkovic, B.

(2015)

TY  - JOUR
AU  - Polic, S.
AU  - Ristic, S.
AU  - Stašić, Jelena
AU  - Trtica, Milan
AU  - Radojkovic, B.
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/287
AB  - This paper presents the results of the morphological and chemical changes on the surface of an Iranian ceramics sample irradiated by a Transversely Excited Atmospheric (TEA) CO2 and an Nd:YAG laser. The sample originates from the archeological site of Yazd (Iran) and is assumed to have been a part of an aqueduct. The effect of laser parameters (energy density (fluency), number of pulses and wavelength) on the induced changes was studied. The tests were performed in order to establish the mechanism of the interaction with the fluence above the damage threshold. This is an essential parameter in the use of lasers for cleaning as well as for eliminating surface defects such as cracks, by melting superficial layers and thus strengthening the objects in question. Another objective was to obtain as much as possible information about the material composition necessary for the conservation and restoration of this ceramics. A TEA CO2 (10.6 mu m wavelength, pulse duration 100 ns (Full Width at Half Maximum - FWHM)) laser and an Nd:YAG laser (wavelength 1064 nm and 532 nm, FWHM = 150 ps) have been used for the surface treatment. Laser fluences were in the range of 1-20 J/cm(2). The ceramics surface morphology modifications, induced by pulsed lasers, were characterized by a scanning electron microscope (SEM), while the composition was examined by energy-dispersive (EDX) and X-ray fluorescence (XRF) spectroscopy. The results show that there are significant differences depending on the laser applied and whether the surface is glazed or not. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
T2  - Ceramics International
T1  - Studies of the Iranian medieval ceramics surface modified by pulsed tea CO2 and Nd:YAG lasers
VL  - 41
IS  - 1
SP  - 85
EP  - 100
DO  - 10.1016/j.ceramint.2014.08.036
ER  - 
@article{
author = "Polic, S. and Ristic, S. and Stašić, Jelena and Trtica, Milan and Radojkovic, B.",
year = "2015",
abstract = "This paper presents the results of the morphological and chemical changes on the surface of an Iranian ceramics sample irradiated by a Transversely Excited Atmospheric (TEA) CO2 and an Nd:YAG laser. The sample originates from the archeological site of Yazd (Iran) and is assumed to have been a part of an aqueduct. The effect of laser parameters (energy density (fluency), number of pulses and wavelength) on the induced changes was studied. The tests were performed in order to establish the mechanism of the interaction with the fluence above the damage threshold. This is an essential parameter in the use of lasers for cleaning as well as for eliminating surface defects such as cracks, by melting superficial layers and thus strengthening the objects in question. Another objective was to obtain as much as possible information about the material composition necessary for the conservation and restoration of this ceramics. A TEA CO2 (10.6 mu m wavelength, pulse duration 100 ns (Full Width at Half Maximum - FWHM)) laser and an Nd:YAG laser (wavelength 1064 nm and 532 nm, FWHM = 150 ps) have been used for the surface treatment. Laser fluences were in the range of 1-20 J/cm(2). The ceramics surface morphology modifications, induced by pulsed lasers, were characterized by a scanning electron microscope (SEM), while the composition was examined by energy-dispersive (EDX) and X-ray fluorescence (XRF) spectroscopy. The results show that there are significant differences depending on the laser applied and whether the surface is glazed or not. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.",
journal = "Ceramics International",
title = "Studies of the Iranian medieval ceramics surface modified by pulsed tea CO2 and Nd:YAG lasers",
volume = "41",
number = "1",
pages = "85-100",
doi = "10.1016/j.ceramint.2014.08.036"
}
Polic, S., Ristic, S., Stašić, J., Trtica, M.,& Radojkovic, B.. (2015). Studies of the Iranian medieval ceramics surface modified by pulsed tea CO2 and Nd:YAG lasers. in Ceramics International, 41(1), 85-100.
https://doi.org/10.1016/j.ceramint.2014.08.036
Polic S, Ristic S, Stašić J, Trtica M, Radojkovic B. Studies of the Iranian medieval ceramics surface modified by pulsed tea CO2 and Nd:YAG lasers. in Ceramics International. 2015;41(1):85-100.
doi:10.1016/j.ceramint.2014.08.036 .
Polic, S., Ristic, S., Stašić, Jelena, Trtica, Milan, Radojkovic, B., "Studies of the Iranian medieval ceramics surface modified by pulsed tea CO2 and Nd:YAG lasers" in Ceramics International, 41, no. 1 (2015):85-100,
https://doi.org/10.1016/j.ceramint.2014.08.036 . .
7
7
12

Interaction of laser beams with carbon textile materials

Srećković, Milesa; Kaluđerović, Branka V.; Kovačević, Aleksander; Bugarinović, Aleksandar; Druzijanic, Dragan

(Emerald Group Publishing Limited, 2015)

TY  - JOUR
AU  - Srećković, Milesa
AU  - Kaluđerović, Branka V.
AU  - Kovačević, Aleksander
AU  - Bugarinović, Aleksandar
AU  - Druzijanic, Dragan
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/856
AB  - Purpose - The purpose of this paper is to present the results of interaction occurring during the exposition of some specific carbon textile materials obtained in laboratory conditions to beams of various laser types. Design/methodology/approach - Carbon fabric materials - fiber, felt and cloth - obtained from different precursor materials and prepared at various process conditions (oxidized, partially carbonized, carbonized, graphitized), were exposed to pulses of various lasers (Nd3+:YAG, alexandrite, ruby). Findings - Depending on the laser power, plasma and destructive phenomena occurred. In the case of an interaction between a Nd3+: YAG laser beam and specimens of thickness in millimeter range, the authors have estimated the threshold of the energy density for drilling and discussed the possible models of the interaction. Research limitations/implications - The results have implications in the estimations of quality as well as in the improvement of material processing, giving some new light to the changes of mechanical and optical constants of the material, as well as to the changes of carbon groups of the material, which would be useful for different types of modeling. Future research will be in the interaction of laser beams with various textile materials, where the investigation would cover the microstructure changes and the implications on cloth cutting and welding, concerning the damages as well as relief structures, specially renew for fs laser regimes. Originality/value - The area of laser applications in the textile industry is supported by scientific and applicative exploration. However, fewer results are concerned with deep introspection into the microstructure of the damages considering the laser interaction with carbon fiber and other carbon-based textiles.
PB  - Emerald Group Publishing Limited
T2  - International Journal of Clothing Science and Technology
T1  - Interaction of laser beams with carbon textile materials
VL  - 27
IS  - 5
SP  - 720
EP  - 737
DO  - 10.1108/IJCST-07-2014-0086
ER  - 
@article{
author = "Srećković, Milesa and Kaluđerović, Branka V. and Kovačević, Aleksander and Bugarinović, Aleksandar and Druzijanic, Dragan",
year = "2015",
abstract = "Purpose - The purpose of this paper is to present the results of interaction occurring during the exposition of some specific carbon textile materials obtained in laboratory conditions to beams of various laser types. Design/methodology/approach - Carbon fabric materials - fiber, felt and cloth - obtained from different precursor materials and prepared at various process conditions (oxidized, partially carbonized, carbonized, graphitized), were exposed to pulses of various lasers (Nd3+:YAG, alexandrite, ruby). Findings - Depending on the laser power, plasma and destructive phenomena occurred. In the case of an interaction between a Nd3+: YAG laser beam and specimens of thickness in millimeter range, the authors have estimated the threshold of the energy density for drilling and discussed the possible models of the interaction. Research limitations/implications - The results have implications in the estimations of quality as well as in the improvement of material processing, giving some new light to the changes of mechanical and optical constants of the material, as well as to the changes of carbon groups of the material, which would be useful for different types of modeling. Future research will be in the interaction of laser beams with various textile materials, where the investigation would cover the microstructure changes and the implications on cloth cutting and welding, concerning the damages as well as relief structures, specially renew for fs laser regimes. Originality/value - The area of laser applications in the textile industry is supported by scientific and applicative exploration. However, fewer results are concerned with deep introspection into the microstructure of the damages considering the laser interaction with carbon fiber and other carbon-based textiles.",
publisher = "Emerald Group Publishing Limited",
journal = "International Journal of Clothing Science and Technology",
title = "Interaction of laser beams with carbon textile materials",
volume = "27",
number = "5",
pages = "720-737",
doi = "10.1108/IJCST-07-2014-0086"
}
Srećković, M., Kaluđerović, B. V., Kovačević, A., Bugarinović, A.,& Druzijanic, D.. (2015). Interaction of laser beams with carbon textile materials. in International Journal of Clothing Science and Technology
Emerald Group Publishing Limited., 27(5), 720-737.
https://doi.org/10.1108/IJCST-07-2014-0086
Srećković M, Kaluđerović BV, Kovačević A, Bugarinović A, Druzijanic D. Interaction of laser beams with carbon textile materials. in International Journal of Clothing Science and Technology. 2015;27(5):720-737.
doi:10.1108/IJCST-07-2014-0086 .
Srećković, Milesa, Kaluđerović, Branka V., Kovačević, Aleksander, Bugarinović, Aleksandar, Druzijanic, Dragan, "Interaction of laser beams with carbon textile materials" in International Journal of Clothing Science and Technology, 27, no. 5 (2015):720-737,
https://doi.org/10.1108/IJCST-07-2014-0086 . .
1

Structural, mechanical and tribological characterization of Zn25Al alloys with Si and Sr addition

Vencl, Aleksandar; Bobić, Ilija; Vučetić, Filip; Bobić, Biljana M.; Ružić, Jovana

(2014)

TY  - JOUR
AU  - Vencl, Aleksandar
AU  - Bobić, Ilija
AU  - Vučetić, Filip
AU  - Bobić, Biljana M.
AU  - Ružić, Jovana
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/144
AB  - The ZA-27 alloy is a zinc-aluminium casting alloy that has been frequently used as the material for sleeves of plain bearings. It has good physical, mechanical and tribological properties. However, one of the major disadvantages is its dimensional instability over a period of time (ageing). To overcome this, copper in the alloy may be replaced with silicon. Coarsening of silicon particles can be controlled by a suitable addition of strontium. In this paper, the commercial ZA-27 alloy and six different Zn25Al alloys (with 1 and 3 wt.% silicon; and with 0, 0.03 and 0.05 wt.% strontium) were obtained by casting in the pre-heated steel mould. Casting of the alloys was carried out at a laboratory level. In the alloys containing silicon, a finer dendritic structure was noticed compared to the structure of the commercial ZA-27 alloy. The addition of strontium influenced the size and distribution of primary silicon particles. Needle-like particles of eutectic silicon were changed into the fibrous ones. The presence of silicon and strontium did not significantly affect mechanical properties of the obtained Zn25Al alloys compared to mechanical properties of the commercial ZA-27 alloy. Wear rate of the alloys containing silicon was lower than that of the ZA-27 alloy. The addition of strontium further lowers the wear rate and slightly increases the coefficient of friction. (C) 2014 Elsevier Ltd. All rights reserved.
T2  - Materials and Design
T1  - Structural, mechanical and tribological characterization of Zn25Al alloys with Si and Sr addition
VL  - 64
SP  - 381
EP  - 392
DO  - 10.1016/j.matdes.2014.07.056
ER  - 
@article{
author = "Vencl, Aleksandar and Bobić, Ilija and Vučetić, Filip and Bobić, Biljana M. and Ružić, Jovana",
year = "2014",
abstract = "The ZA-27 alloy is a zinc-aluminium casting alloy that has been frequently used as the material for sleeves of plain bearings. It has good physical, mechanical and tribological properties. However, one of the major disadvantages is its dimensional instability over a period of time (ageing). To overcome this, copper in the alloy may be replaced with silicon. Coarsening of silicon particles can be controlled by a suitable addition of strontium. In this paper, the commercial ZA-27 alloy and six different Zn25Al alloys (with 1 and 3 wt.% silicon; and with 0, 0.03 and 0.05 wt.% strontium) were obtained by casting in the pre-heated steel mould. Casting of the alloys was carried out at a laboratory level. In the alloys containing silicon, a finer dendritic structure was noticed compared to the structure of the commercial ZA-27 alloy. The addition of strontium influenced the size and distribution of primary silicon particles. Needle-like particles of eutectic silicon were changed into the fibrous ones. The presence of silicon and strontium did not significantly affect mechanical properties of the obtained Zn25Al alloys compared to mechanical properties of the commercial ZA-27 alloy. Wear rate of the alloys containing silicon was lower than that of the ZA-27 alloy. The addition of strontium further lowers the wear rate and slightly increases the coefficient of friction. (C) 2014 Elsevier Ltd. All rights reserved.",
journal = "Materials and Design",
title = "Structural, mechanical and tribological characterization of Zn25Al alloys with Si and Sr addition",
volume = "64",
pages = "381-392",
doi = "10.1016/j.matdes.2014.07.056"
}
Vencl, A., Bobić, I., Vučetić, F., Bobić, B. M.,& Ružić, J.. (2014). Structural, mechanical and tribological characterization of Zn25Al alloys with Si and Sr addition. in Materials and Design, 64, 381-392.
https://doi.org/10.1016/j.matdes.2014.07.056
Vencl A, Bobić I, Vučetić F, Bobić BM, Ružić J. Structural, mechanical and tribological characterization of Zn25Al alloys with Si and Sr addition. in Materials and Design. 2014;64:381-392.
doi:10.1016/j.matdes.2014.07.056 .
Vencl, Aleksandar, Bobić, Ilija, Vučetić, Filip, Bobić, Biljana M., Ružić, Jovana, "Structural, mechanical and tribological characterization of Zn25Al alloys with Si and Sr addition" in Materials and Design, 64 (2014):381-392,
https://doi.org/10.1016/j.matdes.2014.07.056 . .
21
17
25

Tribological properties of A356 Al-Si alloy composites under dry sliding conditions

Vencl, Aleksandar; Bobić, Ilija; Stojanović, Blaža

(2014)

TY  - JOUR
AU  - Vencl, Aleksandar
AU  - Bobić, Ilija
AU  - Stojanović, Blaža
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5894
AB  - Purpose - Aluminium alloys are frequently applied in automotive and other industries, since they provide mass reduction. Besides positive effects, aluminium alloys have their shortcomings reflected, first of all, in inappropriate tribological properties of these materials. The aim of this research was to enable the production of cheap aluminium alloy matrix composite with favourable combination of structural, mechanical and tribological properties, focusing on the tribological behaviour. Design/methodology/approach - The A356 Al-Si alloy was used as a matrix for producing metal matrix composites in compocasting process. Three different materials, in form of particles, were added to the matrix (Al2O3, SiC and graphite). Hardness and tribological properties (wear, friction and wear mechanism) of heat-treated (T6) samples were examined and compared. Tribological tests were carried out on ball-on-block tribometer under dry sliding conditions. Sliding was linear (reciprocating). Counter body was alumina ball. Average velocity was 0.038 m/s (max. 0.06 m/s), sliding distance was 500 m and normal load was 1 N. Findings - The effect of two different ceramic particles and graphite particles on tribological properties of obtained composites was evaluated. Wear resistance of composites reinforced with SiC particles was higher and coefficient of friction was lower compared to the composite reinforced with Al2O3 particles. A dual hybrid composite (with SiC and graphite particles) showed the lowest value of wear rate and friction coefficient. Dominant wear mechanism for all tested material was adhesion. Research limitations/implications - It seems useful to continue the work on developing hybrid composites containing soft graphite particles with A356 Al-Si alloy as matrix. The major task should be to improve particles distribution (especially with higher graphite content) and to explore tribological behaviour in diverse working conditions. Originality/value - Particulate composites with A356 aluminium alloy as a matrix produced in compocasting process using ceramic particles (Al2O3, SiC) were investigated in many researches, but there are only few detailed analyses of dual composites (with the addition of ceramic and graphite particles). In some previous studies, it was shown that compocasting process, as relatively cheap technology, can obtain good structural and mechanical characteristics of composites. In this study, it was shown that even a low graphite content, under specified conditions, can improve tribological properties.
T2  - Industrial Lubrication and Tribology
T1  - Tribological properties of A356 Al-Si alloy composites under dry sliding conditions
VL  - 66
IS  - 1
SP  - 66
EP  - 74
DO  - 10.1108/ILT-06-2011-0047
ER  - 
@article{
author = "Vencl, Aleksandar and Bobić, Ilija and Stojanović, Blaža",
year = "2014",
abstract = "Purpose - Aluminium alloys are frequently applied in automotive and other industries, since they provide mass reduction. Besides positive effects, aluminium alloys have their shortcomings reflected, first of all, in inappropriate tribological properties of these materials. The aim of this research was to enable the production of cheap aluminium alloy matrix composite with favourable combination of structural, mechanical and tribological properties, focusing on the tribological behaviour. Design/methodology/approach - The A356 Al-Si alloy was used as a matrix for producing metal matrix composites in compocasting process. Three different materials, in form of particles, were added to the matrix (Al2O3, SiC and graphite). Hardness and tribological properties (wear, friction and wear mechanism) of heat-treated (T6) samples were examined and compared. Tribological tests were carried out on ball-on-block tribometer under dry sliding conditions. Sliding was linear (reciprocating). Counter body was alumina ball. Average velocity was 0.038 m/s (max. 0.06 m/s), sliding distance was 500 m and normal load was 1 N. Findings - The effect of two different ceramic particles and graphite particles on tribological properties of obtained composites was evaluated. Wear resistance of composites reinforced with SiC particles was higher and coefficient of friction was lower compared to the composite reinforced with Al2O3 particles. A dual hybrid composite (with SiC and graphite particles) showed the lowest value of wear rate and friction coefficient. Dominant wear mechanism for all tested material was adhesion. Research limitations/implications - It seems useful to continue the work on developing hybrid composites containing soft graphite particles with A356 Al-Si alloy as matrix. The major task should be to improve particles distribution (especially with higher graphite content) and to explore tribological behaviour in diverse working conditions. Originality/value - Particulate composites with A356 aluminium alloy as a matrix produced in compocasting process using ceramic particles (Al2O3, SiC) were investigated in many researches, but there are only few detailed analyses of dual composites (with the addition of ceramic and graphite particles). In some previous studies, it was shown that compocasting process, as relatively cheap technology, can obtain good structural and mechanical characteristics of composites. In this study, it was shown that even a low graphite content, under specified conditions, can improve tribological properties.",
journal = "Industrial Lubrication and Tribology",
title = "Tribological properties of A356 Al-Si alloy composites under dry sliding conditions",
volume = "66",
number = "1",
pages = "66-74",
doi = "10.1108/ILT-06-2011-0047"
}
Vencl, A., Bobić, I.,& Stojanović, B.. (2014). Tribological properties of A356 Al-Si alloy composites under dry sliding conditions. in Industrial Lubrication and Tribology, 66(1), 66-74.
https://doi.org/10.1108/ILT-06-2011-0047
Vencl A, Bobić I, Stojanović B. Tribological properties of A356 Al-Si alloy composites under dry sliding conditions. in Industrial Lubrication and Tribology. 2014;66(1):66-74.
doi:10.1108/ILT-06-2011-0047 .
Vencl, Aleksandar, Bobić, Ilija, Stojanović, Blaža, "Tribological properties of A356 Al-Si alloy composites under dry sliding conditions" in Industrial Lubrication and Tribology, 66, no. 1 (2014):66-74,
https://doi.org/10.1108/ILT-06-2011-0047 . .
33
23
35

The effect of processing techniques on microstructural and tribological properties of copper-based alloys

Vencl, Aleksandar; Rajković, Višeslava M.; Živić, Fatima; Mitrovic, Slobodan; Cvijović-Alagić, Ivana; Jovanović, Milan T.

(2013)

TY  - JOUR
AU  - Vencl, Aleksandar
AU  - Rajković, Višeslava M.
AU  - Živić, Fatima
AU  - Mitrovic, Slobodan
AU  - Cvijović-Alagić, Ivana
AU  - Jovanović, Milan T.
PY  - 2013
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5566
AB  - Three copper-based alloys, i.e. two composites reinforced with Al2O3 particles and fabricated through PM route and Cu-Cr-Zr alloy processed by the vacuum melting and casting technique were the object of this investigation. Light microscope, scanning electron microscope (SEM) equipped with electron X-ray spectrometer (EDS) and transmission electron microscope (TEM) were used for microstructural characterization. The ball-on-disc nanotribometer served for wear and friction tests applying low sliding speeds (6, 8 and 10 mm/s) at constant load (1 N). The objective of the paper was to investigate the effect of different processing techniques on microstructure, thermal stability and the tribological characteristics of composites and copper ingot alloy. Nano-sized Al2O3 particles (less than 100 nm in size) are present not only in the copper matrix of Cu-2.5 wt.% Al composite, obtained by internal oxidation, but they are also formed at the grain boundaries preventing the grain growth and providing very small grain size. During the high temperature annealing (in the range 300-950 degrees C) composites behaved much better than the ingot alloy. The highest thermal stability showed Cu-2.5 wt.% Al composite. The pinning effect of nano-sized Al2O3 particles prevents the grain growth slowing down recrystallization of this composite up to 900 degrees C. Micro-sized Al2O3 particles in Cu-5 wt.% Al2O3 composite, processed by mechanical annealing, are not effective in preventing dislocation motion and the grain growth, whereas microstructure of Cu-0.4 wt.% Cr-0.08 wt.% Zr ingot alloy was completely recrystallized around 550 degrees C. Cu-2.5 wt.% Al composite showed the best wear resistance, approximately 2.5 times higher than that of Cu-5 wt.% Al2O3 composite. High hardness and nano-sized Al2O3 particles size combined with the fine-grain structure are the main parameters leading to the improved wear resistance of the Cu-2.5Al composite. (C) 2013 Elsevier B.V. All rights reserved.
T2  - Applied Surface Science
T1  - The effect of processing techniques on microstructural and tribological properties of copper-based alloys
VL  - 280
SP  - 646
EP  - 654
DO  - 10.1016/j.apsusc.2013.05.039
ER  - 
@article{
author = "Vencl, Aleksandar and Rajković, Višeslava M. and Živić, Fatima and Mitrovic, Slobodan and Cvijović-Alagić, Ivana and Jovanović, Milan T.",
year = "2013",
abstract = "Three copper-based alloys, i.e. two composites reinforced with Al2O3 particles and fabricated through PM route and Cu-Cr-Zr alloy processed by the vacuum melting and casting technique were the object of this investigation. Light microscope, scanning electron microscope (SEM) equipped with electron X-ray spectrometer (EDS) and transmission electron microscope (TEM) were used for microstructural characterization. The ball-on-disc nanotribometer served for wear and friction tests applying low sliding speeds (6, 8 and 10 mm/s) at constant load (1 N). The objective of the paper was to investigate the effect of different processing techniques on microstructure, thermal stability and the tribological characteristics of composites and copper ingot alloy. Nano-sized Al2O3 particles (less than 100 nm in size) are present not only in the copper matrix of Cu-2.5 wt.% Al composite, obtained by internal oxidation, but they are also formed at the grain boundaries preventing the grain growth and providing very small grain size. During the high temperature annealing (in the range 300-950 degrees C) composites behaved much better than the ingot alloy. The highest thermal stability showed Cu-2.5 wt.% Al composite. The pinning effect of nano-sized Al2O3 particles prevents the grain growth slowing down recrystallization of this composite up to 900 degrees C. Micro-sized Al2O3 particles in Cu-5 wt.% Al2O3 composite, processed by mechanical annealing, are not effective in preventing dislocation motion and the grain growth, whereas microstructure of Cu-0.4 wt.% Cr-0.08 wt.% Zr ingot alloy was completely recrystallized around 550 degrees C. Cu-2.5 wt.% Al composite showed the best wear resistance, approximately 2.5 times higher than that of Cu-5 wt.% Al2O3 composite. High hardness and nano-sized Al2O3 particles size combined with the fine-grain structure are the main parameters leading to the improved wear resistance of the Cu-2.5Al composite. (C) 2013 Elsevier B.V. All rights reserved.",
journal = "Applied Surface Science",
title = "The effect of processing techniques on microstructural and tribological properties of copper-based alloys",
volume = "280",
pages = "646-654",
doi = "10.1016/j.apsusc.2013.05.039"
}
Vencl, A., Rajković, V. M., Živić, F., Mitrovic, S., Cvijović-Alagić, I.,& Jovanović, M. T.. (2013). The effect of processing techniques on microstructural and tribological properties of copper-based alloys. in Applied Surface Science, 280, 646-654.
https://doi.org/10.1016/j.apsusc.2013.05.039
Vencl A, Rajković VM, Živić F, Mitrovic S, Cvijović-Alagić I, Jovanović MT. The effect of processing techniques on microstructural and tribological properties of copper-based alloys. in Applied Surface Science. 2013;280:646-654.
doi:10.1016/j.apsusc.2013.05.039 .
Vencl, Aleksandar, Rajković, Višeslava M., Živić, Fatima, Mitrovic, Slobodan, Cvijović-Alagić, Ivana, Jovanović, Milan T., "The effect of processing techniques on microstructural and tribological properties of copper-based alloys" in Applied Surface Science, 280 (2013):646-654,
https://doi.org/10.1016/j.apsusc.2013.05.039 . .
9
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