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Journal articles on the topic 'Nanocrystalline copper'

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Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

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1

Bazios, Panagiotis, Konstantinos Tserpes, and Spiros Pantelakis. "Computation of elastic moduli of nanocrystalline materials using Voronoi models of representative volume elements." MATEC Web of Conferences 188 (2018): 02006. http://dx.doi.org/10.1051/matecconf/201818802006.

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In the present work, a numerical model is developed to predict the Young’s modulus and shear modulus of nanocrystalline materials using a Finite Element Analysis. The model is based on Representative Volume Elements (RVE) in which the microstructure of the material is described using the Voronoi tessellation algorithm. The use of the Voronoi particles was based on the observation of the morphology of nanocrystalline materials by Scanning Electron and Transmission Electron Microscopy. In each RVE, three-dimensional modelling of the grain and grain boundaries as randomly-shaped sub-volumes is performed. The developed model has been applied to pure nanocrystallline copper at grain volume fractions of 80%, 90% and 95% taking also into account the parameters of grain size and grain boundary thickness. The elastic moduli of nanocrystalline copper have been computed by loading the RVE in tension. The numerical results reveal that the elastic moduli of nanocrystalline copper increase with increasing the grain volume fraction. On the other hand, for a given grain volume fraction, the results showed no effect of the grain size. The model predictions have been validated successfully against numerical results from the literature and predictions of the Rule of Mixtures and the Mori-Tanaka analytical model.

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2

Sabochick, M. J., and J. A. Lupo. "Diffusion in Nanocrystalline Copper." Defect and Diffusion Forum 66-69 (January 1991): 555–60. http://dx.doi.org/10.4028/www.scientific.net/ddf.66-69.555.

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3

Heim, U., and G. Schwitzgebel. "Electrochemistry of nanocrystalline copper." Nanostructured Materials 12, no. 1-4 (January 1999): 19–22. http://dx.doi.org/10.1016/s0965-9773(99)00058-6.

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4

Witney, A. B., P. G. Sanders, J. R. Weertman, and J. A. Eastman. "Fatigue of nanocrystalline copper." Scripta Metallurgica et Materialia 33, no. 12 (December 1995): 2025–30. http://dx.doi.org/10.1016/0956-716x(95)00441-w.

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5

Zhou, Kai, and Ting Zhang. "Positron Lifetime Calculation for Plastic Deformed Nanocrystalline Copper." Defect and Diffusion Forum 373 (March 2017): 31–34. http://dx.doi.org/10.4028/www.scientific.net/ddf.373.31.

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Positron lifetime calculation has been performed on a computer-generated nanocrystalline copper with a mean grain size of 9.1 nm during its deformation. For the undeformed and deformed nanocrystalline copper, calculated positron lifetimes are around 157 ps which come from the positron annihilation in the free volume in grain boundaries. Due to the grain-boundary deformation mechanism, no vacancies or vacancy clusters will be induced in grains during the plastic deformation of the nanocrystalline copper, which is different to the deformation of the conventional polycrystal. From this point of view, in-situ positron annihilation measurements can provide important experimental information on the deformation mechanism of nanocrystalline metals.

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6

CAO, PENG, and DELIANG ZHANG. "THERMAL STABILITY OF NANOCRYSTALLINE COPPER FILMS." International Journal of Modern Physics B 20, no. 25n27 (October 30, 2006): 3830–35. http://dx.doi.org/10.1142/s0217979206040441.

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The grain growth kinetics of nanocrystalline copper thin film samples was investigated. The grain size of nanocrystalline copper samples was determined from the broadening of X-ray spectra. It was found that the grain size increased linearly with isothermal annealing time within the first 10 minutes, beyond which power-law growth kinetics is applied. The activation energy for grain growth was determined by constructing an Arrhenius plot, which shows an activation energy of about 21 – 30 kJ/mol. The low activation energy is attributed to the second phase particle drag and the porosity drag, which act as the pinning force for grain growth in nanocrystalline copper.

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7

Tanimoto, Hisanori, Nobuyori Yagi, Takanori Yamada, and Hiroshi Mizubayashi. "OS06W0399 Characterization and mechanical properties of high-density nanocrystalline copper." Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2003.2 (2003): _OS06W0399. http://dx.doi.org/10.1299/jsmeatem.2003.2._os06w0399.

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8

Chen, Jin Song, Yin Hui Huang, Bin Qiao, Jian Ming Yang, and Yi Qiang He. "Rapid Prototyped Nanocrystalline Copper Parts by Jet Electrodeposition." Materials Science Forum 682 (March 2011): 3–7. http://dx.doi.org/10.4028/www.scientific.net/msf.682.3.

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The system components and the theory of jet electrodeposition orientated by rapid prototyping (RP) are introduced.The nanocrystalline copper parts with simple shape were fabricated by RP technology. The microstructure evolution of the nanocrystalline Copper layer was examined by means of the Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). The results show that the jet electrodeposition can greatly enhance the limited current density, fine crystalline particles and improve deposition quality. The copper deposited layers have nanocrystalline microstructure with average size of 55.6nm. The grain size decreases to 41.4 nm in crystal plane (311).

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9

Saremi, M., and M. Abouie. "Oxidation and Corrosion Resistance of Nanocrystalline Copper Deposit Produced by Pulse Electrodeposition." Advanced Materials Research 264-265 (June 2011): 1519–25. http://dx.doi.org/10.4028/www.scientific.net/amr.264-265.1519.

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Pulse electrodeposition was used to produce nanocrystalline (nc) copper from copper sulfate electrolyte with saccharin as additive. The grain size of nanocrystalline coatings was determined using x-ray diffraction and atomic force microscopy (AFM) which was about 30 nm. Microcrystalline copper deposits were also produced by direct current electrodeposition processes and compared with pulse plated ones. Corrosion behavior of the coatings was investigated using polarization and Impedance measurements in different solutions. The oxidation test was carried out at 650°C in an electrical furnace. It was demonstrated that the nanocrystalline film was markedly superior to regularly grained films made by direct current (DC) plating; nanocrystalline deposits show higher corrosion resistance and much higher oxidation resistance.

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10

Bazios, Panagiotis, Konstantinos Tserpes, and Spiros Pantelakis. "Prediction of mechanical properties of nanocrystalline materials using Voronoi FE models of representative volume elements." MATEC Web of Conferences 233 (2018): 00029. http://dx.doi.org/10.1051/matecconf/201823300029.

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In the present work, a numerical model is developed to predict the mechanical properties of nanocrystalline materials using a Finite Element Analysis. The model is based on Representative Volume Elements (RVE) in which the microstructure of the material is described using the Voronoi tessellation algorithm. The use of the Voronoi particles was based on the observation of the morphology of nanocrystalline materials by Scanning Electron and Transmission Electron Microscopy. In each RVE, three-dimensional modelling of the grain and grain boundaries as randomlyshaped sub-volumes is performed. The developed model has been applied to pure nanocrystallline copper taking into account the parameters of grain size and grain boundary thickness. The mechanical properties of nanocrystalline copper have been computed by loading the RVE in tension. The numerical results gave a clear evidence of grain size effect and the Hall-Petch relationship, which is a consequence of macroscopic strain being preferentially accumulated at grain boundaries. On the other hand, for a given grain volume fraction, the results for elastic moduli showed no effect of the grain size. The model predictions have been validated successfully against numerical results from the literature and predictions of the Rule of Mixtures and the Mori-Tanaka analytical model.

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11

SAREMI, MOHSEN, MARYAM ABOUIE, and R. VAGHAR. "ELECTROCHEMICAL AND PHYSICAL PROPERTIES OF NANOCRYSTALLINE COPPER DEPOSITS PRODUCED BY PULSE ELECTRODEPOSITION." International Journal of Modern Physics B 22, no. 18n19 (July 30, 2008): 3005–12. http://dx.doi.org/10.1142/s0217979208047869.

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This paper reports our recent studies on nanocrystalline layer of copper produced using pulse plating method. The grain size of the copper layer was about 60 nm. Electrochemical and physical Properties of the nanocrystalline surface were investigated using Potentiostatic scanning and Impedance measurements. Microcrystalline copper deposits were also produced by direct current electrodeposition processes and compared with pulse plated ones. Effects of deposition parameters, such as the peak Density, frequency, current-on time and current-off time of the pulse current (PC), on the grain size were investigated for the purpose of process optimization. It was demonstrated that the nanocrystalline film was markedly superior to regularly grained film made by direct current (DC) plating; the nanocrystalline deposit shows higher electrochemical stability and lower electrical resistance.

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12

Shanthi, M., C. Y. H. Lim, and Manoj Gupta. "Tribological Characteristics of Nanocrystalline Copper." Journal of Metastable and Nanocrystalline Materials 23 (January 2005): 267–70. http://dx.doi.org/10.4028/www.scientific.net/jmnm.23.267.

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In the present study, two sets of powder metallurgy copper samples, with grain sizes of 99 nm and 63 nm, respectively, were investigated under different tribological conditions. The wear behavior of these materials was studied through a pin-on-disc configuration using sliding velocities of 0.5, 1 and 2 m/s with normal loads of 10 and 30 N. The finer-grained copper was able to outperform (by between 4- to 16-fold) its coarser-grained counterpart under severe test conditions, but no advantage was observed when conditions were milder. Scanning electron microscopy revealed the dominant wear mechanisms to be oxidative wear under mild sliding, with a transition to adhesive wear with increases in sliding speed and normal load.

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13

Gräf, C. "Potentiometrical investigations of nanocrystalline copper." Solid State Ionics 131, no. 1-2 (June 1, 2000): 165–74. http://dx.doi.org/10.1016/s0167-2738(00)00631-7.

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14

Guduru, Ramesh K., K. Linga Murty, Khaled M. Youssef, Ronald O. Scattergood, and Carl C. Koch. "Mechanical behavior of nanocrystalline copper." Materials Science and Engineering: A 463, no. 1-2 (August 2007): 14–21. http://dx.doi.org/10.1016/j.msea.2006.07.165.

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15

Youngdahl, C. J., J. R. Weertman, R. C. Hugo, and H. H. Kung. "Deformation behavior in nanocrystalline copper." Scripta Materialia 44, no. 8-9 (May 2001): 1475–78. http://dx.doi.org/10.1016/s1359-6462(01)00712-6.

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16

Fais, Alessandro, Matteo Leoni, and Paolo Scardi. "Fast Sintering of Nanocrystalline Copper." Metallurgical and Materials Transactions A 43, no. 5 (May 17, 2011): 1517–21. http://dx.doi.org/10.1007/s11661-011-0727-7.

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17

Huang, Y. K., A. A. Menovsky, and F. R. de Boer. "Electrical resistivity of nanocrystalline copper." Nanostructured Materials 2, no. 5 (September 1993): 505–13. http://dx.doi.org/10.1016/0965-9773(93)90168-b.

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18

Qin, Ying, Peng Yuan Zhang, and Jian Feng Chen. "Preparation of Nanocrystalline Copper Powders by Aqueous Reduction." Advanced Materials Research 11-12 (February 2006): 575–78. http://dx.doi.org/10.4028/www.scientific.net/amr.11-12.575.

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This paper aims at a simple preparation method of nanocrystalline copper powders through copper sulfate reduction by potassium borohydride in aqueous solution. The product powders obtained in various conditions were investigated by X-ray powder diffraction, transmission electron microscope and particle size distribution analyzer. The parameters that influence the preparation process of copper crystalline were researched, such as the effect of complexing agent, the molar ratio of copper sulfate to potassium borohydride and the quantity of protective polymer. Finally, the preferable reaction conditions were determined, and well-dispersed nanocrystalline copper powders with average diameter of 28.4nm were obtained.

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19

Rodríguez Baracaldo, Rodolfo, Jose Antonio Benito Páramo, and José María Cabrera Marrero. "Nanocrystalline and ultrafine grain copper obtained by mechanical attrition." Ingeniería e Investigación 30, no. 1 (January 1, 2010): 141–45. http://dx.doi.org/10.15446/ing.investig.v30n1.15223.

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This article presents a method for the sample preparation and characterisation of bulk copper having grain size lower than 1 µm (ultra-fine grain) and lower than 100 nm grain size (nanocrystalline). Copper is initially manufactured by a milling/alloying mechanical method thereby obtaining a powder having a nanocrystalline structure which is then consolidated through a process of warm compaction at high pressure. Microstructural characterisation of bulk copper samples showed the evolution of grain size during all stages involved in obtaining it. The results led to determining the necessary conditions for achieving a wide range of grain sizes. Mechanical characterisation indicated an increase in microhardness to values of around 3.40 GPa for unconsolidated nanocrystalline powder. Compressive strength was increased by reducing the grain size, thereby obtaining an elastic limit of 650 MPa for consolidated copper having a ~ 62 nm grain size.

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20

Honkanen, Mari, Minnamari Vippola, and Toivo Lepistö. "Oxidation of copper alloys studied by analytical transmission electron microscopy cross-sectional specimens." Journal of Materials Research 23, no. 5 (May 2008): 1350–57. http://dx.doi.org/10.1557/jmr.2008.0160.

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In this work, the oxide structures of three polycrystalline copper grades, unalloyed oxygen-free (OF) copper and alloyed CuAg and deoxidized high-phosphor (DHP) copper, were studied using cross-sectional analytical transmission electron microscopy (AEM) samples. The oxidation treatments were carried out in air at 200 and 350 °C for different exposure times. The detailed oxide layer structures were characterized by AEM. At 200 °C, a nano-sized Cu2O layer formed on the all copper grades. At 350 °C, a nano-sized Cu2O layer formed first on the all copper grades. After longer exposure time at 350 °C, a crystalline CuO layer grew on the Cu2O layer of the unalloyed OF-copper. In the case of the alloyed CuAg- and DHP-copper, a crystalline and columnar shaped layer, consisting of Cu2O and CuO grains, formed on the nanocrystalline Cu2O layer. At 350 °C, the unalloyed copper oxidized notably slower than the alloyed coppers, and its oxide structures were different than those of the alloyed coppers.

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21

Rajgarhia, Rahul K., Douglas E. Spearot, and Ashok Saxena. "Plastic deformation of nanocrystalline copper-antimony alloys." Journal of Materials Research 25, no. 3 (March 2010): 411–21. http://dx.doi.org/10.1557/jmr.2010.0072.

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Molecular dynamics simulations are used to evaluate the influence of Sb dopant atoms at the grain boundaries on plastic deformation of nanocrystalline Cu. Deformation is conducted under uniaxial tensile loading, and Sb atoms are incorporated as substitutional defects at the grain boundaries. The presence of randomly dispersed Sb atoms at the grain boundaries does not appreciably influence the mechanisms associated with dislocation nucleation in nanocrystalline Cu; grain boundary ledges and triple junctions still dominate as partial dislocation sources. However, the magnitude of the tensile stress associated with the partial dislocation nucleation event does increase with increasing Sb concentration and also with increasing grain size. The flow stress of nanocrystalline Cu increases with increasing Sb concentration up to 1.0 at.% Sb, with a maximum observed at a grain size of 15 nm for all Sb concentrations (0.0–2.0 at.% Sb).

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22

Simões, Sonia, Rosa Calinas, P. J. Ferreira, M. Teresa Vieira, Filomena Viana, and Manuel F. Vieira. "Effect of Annealing Conditions on the Grain Size of Nanocrystalline Copper Thin Films." Materials Science Forum 587-588 (June 2008): 483–87. http://dx.doi.org/10.4028/www.scientific.net/msf.587-588.483.

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Nanocrystalline metals demonstrate a broad range of fascinating mechanical properties at the nanoscale, namely a significant increase in hardness and superior yield stress. In this regard, understanding grain growth in nanocrystalline metals is crucial, particularly because nano size grains are characterized by a high curvature, which results in a high driving force for grain growth. In this work, the effect of annealing conditions on grain size of copper nanocrystalline thin films was investigated. The nanocrystalline copper thin films were first deposited by d.c. magnetron sputtering on a copper substrate. The specimens were then annealed in vacuum at 100, 300 and 500°C from 10 minutes to 5 hours. Transmission electron microscopy observations revealed that the as-deposited thin films have a bimodal grain size distribution; an average grain size of 43±2nm and the presence of nanotwins. Abnormal grain growth was observed for some samples annealed. Increasing the annealing time induced significant grain growth and promoted twin formation in the larger grains. Finally, the hardness of these nanocrystalline Cu thin films was determined using atomic force microscope. The relation between mechanical properties, annealing conditions and grain size was analyzed.

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23

Bandyopadhyay, S., and D. Chakravorty. "Preparation of nanocrystalline copper by electrodeposition." Journal of Materials Research 12, no. 10 (October 1997): 2719–24. http://dx.doi.org/10.1557/jmr.1997.0362.

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Copper particles of sizes in the range 3.1 to 11.4 nm have been grown within gel compositions of the system CuO–SiO2 by an electrodeposition process applying voltages varying from 5 to 15 V. Composite films of these metal particles dispersed in a polystyrene matrix have been prepared on Corning No. 7059 glass slides by a dip-coating technique and their optical absorption characteristics have been delineated. The spectra show maxima at wavelengths in the range 380 to 470 nm, depending on the particle size. The results have been analyzed using the Mie theory. The electrical conductivity as extracted from this analysis is found to have reasonable correspondence with data reported earlier for copper nanoparticles in glass-ceramic systems.

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24

Kim, Hyoung Seop, and Yuri Estrin. "Modelling Mechanical Properties of Nanocrystalline Copper." Materials Science Forum 437-438 (October 2003): 351–54. http://dx.doi.org/10.4028/www.scientific.net/msf.437-438.351.

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25

Arbuzova, T. I., S. V. Naumov, V. L. Arbuzov, K. V. Shal’nov, A. E. Ermakov, and A. A. Mysik. "Surface magnetism of nanocrystalline copper monoxide." Physics of the Solid State 45, no. 2 (February 2003): 304–10. http://dx.doi.org/10.1134/1.1553536.

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26

Lu, L., L. B. Wang, B. Z. Ding, and K. Lu. "High-tensile ductility in nanocrystalline copper." Journal of Materials Research 15, no. 2 (February 2000): 270–73. http://dx.doi.org/10.1557/jmr.2000.0043.

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In this work we report a high-tensile ductility in a fully dense bulk nanocrystalline (nc) pure copper sample prepared by electrodeposition. A tensile ductility with an elongation to fracture of 30% was obtained in the nc Cu specimen with an average grain size of 27 nm, which is comparable to that for the coarse-grained polycrystalline Cu. An enhanced yield stress (119 MPa) and a depressed strain hardening exponent (0.22) were observed in the nc Cu sample with respect to the conventional polycrystalline Cu. The high-tensile ductility was attributed to the minimized artifacts in the nc sample, and the grain-boundary sliding deformation mechanism resulted from the numerous amount small-angle grain boundaries and the low microstrain (dislocation density).

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27

Panagopoulos, C. N., G. D. Plainakis, and D. A. Lagaris. "Nanocrystalline Ni–W coatings on copper." Materials Science and Engineering: B 176, no. 6 (April 2011): 477–79. http://dx.doi.org/10.1016/j.mseb.2010.03.058.

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28

Folmanis, G. �., and V. A. Uglov. "Nanocrystalline copper powders produced by electrolysis." Soviet Powder Metallurgy and Metal Ceramics 30, no. 2 (February 1991): 95–96. http://dx.doi.org/10.1007/bf00797278.

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29

Zhang, Zhikun, Zuolin Cui, Chuncheng Hao, Lifeng Dong, Zhaoguo Meng, and Liyan Yu. "Defect of nanocrystalline copper and silver." Science in China Series B: Chemistry 41, no. 1 (February 1998): 30–35. http://dx.doi.org/10.1007/bf02875553.

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30

Wang, Y. M., K. Wang, D. Pan, K. Lu, K. J. Hemker, and E. Ma. "Microsample tensile testing of nanocrystalline copper." Scripta Materialia 48, no. 12 (June 2003): 1581–86. http://dx.doi.org/10.1016/s1359-6462(03)00159-3.

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31

Lu, L., M. L. Sui, and K. Lu. "Cold rolling of bulk nanocrystalline copper." Acta Materialia 49, no. 19 (November 2001): 4127–34. http://dx.doi.org/10.1016/s1359-6454(01)00248-8.

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32

C̆ížek, J., I. Procházka, P. Vostrý, F. Chmelík, and R. K. Islamgaliev. "Positron Lifetime Spectroscopy of Nanocrystalline Copper." Acta Physica Polonica A 95, no. 4 (April 1999): 487–95. http://dx.doi.org/10.12693/aphyspola.95.487.

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33

Krasilnikov, Nikolay A., and Georgy I. Raab. "Grain Boundary Effects in Nanocrystalline Copper." Materials Science Forum 294-296 (November 1998): 701–6. http://dx.doi.org/10.4028/www.scientific.net/msf.294-296.701.

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34

Hwang, Seung J., D. Wexler, and A. Calka. "Mechanochemical synthesis of nanocrystalline Al2O3dispersed copper." Journal of Materials Science 39, no. 14 (July 2004): 4659–62. http://dx.doi.org/10.1023/b:jmsc.0000034165.79830.d7.

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35

Fais, A., and P. Scardi. "Capacitor discharge sintering of nanocrystalline copper." Zeitschrift für Kristallographie Supplements 2008, no. 27 (February 2008): 37–44. http://dx.doi.org/10.1524/zksu.2008.0006.

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36

Zhang, Xiaopu, Jian Han, John J. Plombon, Adrian P. Sutton, David J. Srolovitz, and John J. Boland. "Nanocrystalline copper films are never flat." Science 357, no. 6349 (July 27, 2017): 397–400. http://dx.doi.org/10.1126/science.aan4797.

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37

Sharma, P., and S. Ganti. "On the grain-size-dependent elastic modulus of nanocrystalline materials with and without grain-boundary sliding." Journal of Materials Research 18, no. 8 (August 2003): 1823–26. http://dx.doi.org/10.1557/jmr.2003.0253.

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A closed-form model was proposed to evaluate the elastic properties of nanocrystalline materials as a function of grain size. Grain-boundary sliding, present in nanocrystalline materials even at relatively low temperatures, was included in the formulation. The proposed analytical model agrees reasonably well with the experimental results for nanocrystalline copper and palladium.

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38

El-Atwani, Osman, Hyosim Kim, Cayla Harvey, Mert Efe, and Stuart A. Maloy. "Limitations of Thermal Stability Analysis via In-Situ TEM/Heating Experiments." Nanomaterials 11, no. 10 (September 28, 2021): 2541. http://dx.doi.org/10.3390/nano11102541.

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This work highlights some limitations of thermal stability analysis via in-situ transmission electron microscopy (TEM)-annealing experiments on ultrafine and nanocrystalline materials. We provide two examples, one on nanocrystalline pure copper and one on nanocrystalline HT-9 steel, where in-situ TEM-annealing experiments are compared to bulk material annealing experiments. The in-situ TEM and bulk annealing experiments demonstrated different results on pure copper but similar output in the HT-9 steel. The work entails discussion of the results based on literature theoretical concepts, and expound on the inevitability of comparing in-situ TEM annealing experimental results to bulk annealing when used for material thermal stability assessment.

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39

Musa, Aminu, Mansor B. Ahmad, Mohd Zobir Hussein, Saiman Mohd Izham, Kamyar Shameli, and Hannatu Abubakar Sani. "Synthesis of Nanocrystalline Cellulose Stabilized Copper Nanoparticles." Journal of Nanomaterials 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/2490906.

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A chemical reduction method was employed for the synthesis of copper nanoparticles stabilized by nanocrystalline cellulose (NCC) using different concentrations of copper salt in aqueous solution under atmospheric air. CuSO4·5H2O salt and hydrazine were used as metal ion precursor and reducing agent, respectively. Ascorbic acid and aqueous NaOH were also used as an antioxidant and a pH moderator, respectively. The number of CuNPs increased with increasing concentration of the precursor salt. The formation of copper nanoparticles stabilized by NCC (CuNPs@NCC) was investigated by UV-visible spectroscopy (UV-vis), where the surface absorption maximum was observed at 590 nm. X-ray diffraction (XRD) analysis showed that the CuNPs@NCC are of a face-centered cubic structure. Moreover, the morphology of the CuNPs@NCC was investigated using transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM), which showed well-dispersed CuNPs with an average particle size less than 4 nm and the shape of CuNPs was found to be spherical. Energy dispersive X-ray spectroscope (EDS) also confirmed the presence of CuNPs on the NCC. The results demonstrate that the stability of CuNPs decreases with an increasing concentration of the copper ions.

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40

Wang, Jin Xiang, Nan Zhou, and Zheng Zhao. "Factors Effect on Grain Refining of Nanocrystalline Copper Fabricated by Explosive Loading and its Dynamic Mechanical Property." Advanced Materials Research 150-151 (October 2010): 1530–36. http://dx.doi.org/10.4028/www.scientific.net/amr.150-151.1530.

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By the method of severe plastic deformation at high strain rate of coarse-grained copper under explosively dynamic loading, nanocrystalline(NC) copper was fabricated. The deformation process were simulated recur to Ls-Dyna3d finite element program , the effects of the strain on the degree of grain-refining were analysed. Finally, the dynamic mechanical properties of the NC copper were researched recur to split Hopkinson pressure bar(SHPB). The results show that it is feasible to fabricate nanocrystalline copper by explosively dynamic plastic deformation of coarse-grained copper and the grain size of the NC copper can be controlled less than 100 nanometer; higher strain at high strain rate is beneficial to the grain refining; the distribution of the grain size is not uniform along the loading direction; dynamic yield strength of the NC copper enhences with the decreasing of the average grain size and increasing of the strain rate.

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41

Fan, Hui, Yang Pei Zhao, and Shan Kui Wang. "Technical Study of Jet Electrodeposition in Manufacture of Metal Parts." Key Engineering Materials 667 (October 2015): 259–64. http://dx.doi.org/10.4028/www.scientific.net/kem.667.259.

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Jet electrodeposition is one of electrochemical machining methods, which is able to increase cathodic current density, therefore having high deposition rate, good locality and nanocrystalline structure. These advantages enable jet electro-deposition to integrate with rapid prototyping technology in an effort to achieve selective electro-deposition on the cathode surface. This paper combine both methods to prepare nanocrystalline copper parts. The equipment system is developed, which is mainly composed of computer control system, machine body, electrolyte circulation system, nozzle and its hoisting mechanism and other parts. Deposition rate, locality, deposit thickness distribution and forming accuracy are analyzed. A group of nanocrystalline copper parts having good shape and size precision have been prepared. Influencing factors on forming accuracy are analyzed.

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42

Mahmoud, Arshad Ahmed, and Mohammad J.F. "Copper Doping Effect on Nanocrystalline Tin Oxide (SnO2) Thin Films for Gas Sensing Applications." NeuroQuantology 20, no. 5 (May 18, 2022): 723–28. http://dx.doi.org/10.14704/nq.2022.20.5.nq22228.

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In this work, Nanocrystalline SnO2 and copper doped SnO2 with (SnO2:Cu, Cu: 1%, 3%, 5%) was grown on glass substrates at (350 °C) via chemical pyrolysis method. The results of the structural properties using XRD analysis showed that The films have diffraction angles of different intensities and have a tetragonal crystal structure. The intensity decreases with an increased doping ratio. Atomic force microscopy showed that with increasing copper doping, the average grain size decreased. Transmittance of the prepared films is greater than 70% at 550 nm. The energy gap of the calculated tin oxide is 3.9 eV and decreases with increasing copper doping, while the absorption coefficient increases with increasing Cu ratio.

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Sleman, Ulla M. "Synthesis and characterization of nanocrystalline copper sulfide powders." Iraqi Journal of Physics (IJP) 16, no. 38 (October 30, 2018): 124–31. http://dx.doi.org/10.30723/ijp.v16i38.14.

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Nanocrystalline copper sulphide (Cu2-xS) powders were synthesized by chemical precipitation from their aqueous solutions composed of different molar ratio of copper sulfate dehydrate (CuSO4.5H2O) and thiorea (NH2)2CS as source of Cu+2, S-2 ions respectively, and sodium ethylene diamine tetra acetic acid dehydrate (EDTA) as a complex agent. The compositions, morphological and structural properties of the nanopowders were characterized by energy dispersive spectroscopy (EDS), scanning electron microscope (SEM), and X-ray diffraction (XRD), respectively. The compositional results showed that the copper content was high and the Sulfur content was low for both CuS and Cu2S nanopowders. SEM images shows that all products consist of aggregate of fine nanospheres with uniform distribution and the size of the particles formed are in nanometer range. XRD results revealed that the obtained powders contains a mixture of copper sulfide phases specially the intermediate phases and the rough estimate of the average crystallite size using the Scherrer formula gives a range of values (4.1-36.9) nm.

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Wang, Jin Xiang, Nan Zhou, and Rui Yang. "Study on the Fabrication of Nanocrystalline Copper by Explosive Dynamic Loading." Materials Science Forum 667-669 (December 2010): 109–14. http://dx.doi.org/10.4028/www.scientific.net/msf.667-669.109.

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By the method of severe plastic deformation at high strain rate of coarse-grained copper under explosively dynamic loading, nanocrystalline copper with the average grain size less than 200 nanometer was fabricated. The mechanism of grain-refining was investigated by means of transmission electron microscopy. Finally, the deformation processes were simulated using Ls-Dyna3d finite element program and the effects of the strain, strain rate as well as temperature rise on grain-refining were analysed systematically. The results show that it is feasible to fabricate nanocrystalline copper by explosively dynamic plastic deformation of coarse-grained copper; twin crystal and dislocation are the main mechanism of grain-refining; higher strain and lower temperature rise are beneficial to the grain refining; the distribution of the grain size is not uniform along the loading direction.

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Ding, Liu Wei, Hao Ran Geng, and Jing Hua Xu. "Fabrication and Characterization of Nanoscale Porous Copper Film." Advanced Materials Research 433-440 (January 2012): 683–88. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.683.

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Cu-38Zn thin film (wt %) was deposited on the unheated microscope glass at the nanometer scale by DC magnetron sputtering. Subsequently, the nanocrystalline films were dealloyed in H2SO4 aqueous solution etching of zinc component, resulting in the formation of nanoscale porous copper film with average porous diameter of approximately 94 nm. The films microstructure and element composition were characterized by X-ray diffraction and scanning electron microscopy. The experimental results show that Cu-38Zn films are quasi-amorphous structure, porous copper film with different porous sizes is prepared by selective dissolution of zinc atoms from a nanocrystalline dual-phase film under free corrosion conditions, the grain size of the Cu-Zn films has an important effect on the dealloying process and the microstructures of the nanoscale copper films.

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Wang, Y. M., M. W. Chen, H. W. Sheng, and E. Ma. "Nanocrystalline grain structures developed in commercial purity Cu by low-temperature cold rolling." Journal of Materials Research 17, no. 12 (December 2002): 3004–7. http://dx.doi.org/10.1557/jmr.2002.0436.

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Nanocrystalline pure copper was obtained by cold rolling a commercial bulk Cu to very large extensions at subambient temperatures. The eventual formation of nanocrystalline grain structures is attributed to dynamic grain refinement (recrystallization) mechanisms activated by the low-temperature continuous plastic deformation that leads to ultrahigh densities of dislocations.

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Panagopoulos, Christos N., Georgios D. Plainakis, and Maria G. Tsoutsouva. "Corrosion of Nanocrystalline Ni-W Coated Copper." Journal of Surface Engineered Materials and Advanced Technology 05, no. 02 (2015): 65–72. http://dx.doi.org/10.4236/jsemat.2015.52007.

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Lang, Eric, Mike Marshall, Henry Padilla, Brad Boyce, and Khalid Hattar. "In-situ TEM Cryoindentation of Nanocrystalline Copper." Microscopy and Microanalysis 27, S1 (July 30, 2021): 1492–93. http://dx.doi.org/10.1017/s1431927621005493.

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Rigsbee, J. M. "Development of Nanocrystalline Copper-Refractory Metal Alloys." Materials Science Forum 561-565 (October 2007): 2373–78. http://dx.doi.org/10.4028/www.scientific.net/msf.561-565.2373.

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Precipitation-strengthened Cu-based alloys have limited use as structural materials at high temperatures due to precipitate coarsening and strength loss. We have recently shown that Curefractory metal alloys produced by various physical vapor deposition methods have stable, nanocrystalline microstructures and maintain their strength properties even when annealed at temperatures as high as 900 C for up to 100 hours. This paper presents discussions of how these alloys are processed and the resulting microstructures. X-ray and electron microscopy results will be presented to document the phase transformations that occur in these alloys and result in such exceptionally stable microstructures.

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Siow, K. S., A. A. O. Tay, and P. Oruganti. "Mechanical properties of nanocrystalline copper and nickel." Materials Science and Technology 20, no. 3 (March 2004): 285–94. http://dx.doi.org/10.1179/026708304225010460.

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