Journal articles: 'Conductivity and resistance matrix'

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Sugio, Kenjiro, Keisuke Kono, Yong Bum Choi, and Gen Sasaki. "Evaluation of Effective Thermal Conductivity of Metal Matrix Composites by Using Image-Based Calculation." Materials Science Forum 941 (December 2018): 1939–43. http://dx.doi.org/10.4028/www.scientific.net/msf.941.1939.

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Interfacial thermal resistance in Al-SiC composites was evaluated by comparing the measured thermal conductivity and the calculated thermal conductivity. Al-20vol.%SiC composites changing SiC particle size, 3 μm to 30 μm, was fabricated by spark plasma sintering and heat treatment. Effective thermal conductivity was measured with the steady state thermal conductivity measuring device. Effective thermal conductivity was also calculated by using SEM image and the measured relative density. Comparing the measured thermal conductivity and the calculated thermal conductivity, interfacial thermal resistance in Al-SiC composites was evaluated as about 1.0x10-8 (m2K)/W.

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Aoki, Toi, Noboru Nakayama, Masaomi Horita, and Hiroaki Fukui. "Influence of Elastic Modulus of Matrix on Conductivity of VGCF Dispersed in Plastic Matrix." Materials Science Forum 1016 (January 2021): 243–49. http://dx.doi.org/10.4028/www.scientific.net/msf.1016.243.

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Pressure-sensitive conductive material is used for various pressure sensors consists of a polymer nanocomposite with carbon nanotubes (VGCF). And the resistance in it were changed by adding applied load. Recently, carbon nanotubes (VGCF) has drawn attention as a function filler that imparts various functions to a resin, including electrical properties. In polycarbonate (PC) composite with VGCF, the resistance decreases with increase in applied load. And increase of the addition amount of VGCF was enhanced the mechanical properties and electronic properties. In addition, this conclusion suggested that strain of PC/VGCF caused reducing the resistance. Therefore, changing matrix is predictably effective on electrical properties in pressure-conductive materials. In the present study, we used various matrix had different elastic modulus. The addition amount of VGCF was 12.5% volume rate. We made silicone/VGCF and polyethylene (PE)/VGCF and polycarbonate (PC)/VGCF by twin screw extruder and injection moldings. To clarify the influence of elastic modulus of matrix on conductivity of VGCF dispersed plastic matrix composites. The experimental results showed that conductive property of pressure-sensitive conductive materials is related to elastic modulus of them.

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Siddiqui, M. U., U. Hayat, Abul Arif, and N. Saheb. "On the thermal conductivity of spark plasma sintered alumina hybrid nanocomposites: Estimation modeling and experimental validation." Science of Sintering 51, no. 1 (2019): 101–14. http://dx.doi.org/10.2298/sos1901101s.

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In the current work, an improved model to estimate the thermal conductivity of spark plasma sintered nanocomposites is presented. In the developed model, the thermal conductivity of the matrix was modeled as a function of the average matrix crystallite size rather than taking a constant matrix thermal conductivity. The model has been validated against experimentally measured thermal conductivity of Al2O3-SiC-CNT hybrid nanocomposites. Using the experimental and modeling results, it was shown that the addition of SiC and CNT inclusions to alumina resulted in a decrease in its thermal conductivity. The main reason for this decrease was found to be the reduction in the thermal conductivity of the alumina matrix itself because of the reduction in the crystallite size. Additional reduction in the composite thermal conductivity was due to the matrix-inclusion interface resistance and porosity. The predicted and measured thermal conductivities were found to be in good agreement.

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Zhang, M., Peng Cheng Zhai, and Qing Jie Zhang. "The Effective Conductivity of Multiphase Composites with Imperfect Thermal Contact at Constituent Interfaces." Materials Science Forum 631-632 (October 2009): 127–32. http://dx.doi.org/10.4028/www.scientific.net/msf.631-632.127.

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This paper studies the effective thermal conductivity of multiphase composite in which a thermal boundary resistance exists at constituent interfaces. Based on the theoretical framework of conductivity for binary system composites in the presence of a thermal contact resistance between matrix and inclusion given by Y. Benveniste and T. Miloh (1986), the fundamental concept is generalized for the case of multiphase composites with imperfect contact which permits a temperature discontinuity between matrix and inclusions of different phases. A micromechanics model, the “generalized self-consistent scheme (GSCS)” based on a particle-matrix embedding in the effective medium, is generalized to evaluate the effective conductivity of multiphase medium with imperfect thermal contact at constituent interfaces. Numerical results are given for three-phase particulate composites with spherical particles to illustrate the effect of imperfect interfaces on the effective thermal conductivity of multiphase composites.

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Li, Xiao Tuo, Xin Yu Fan, Ying Dan Zhu, and Juan Li. "Thermal Modeling of Randomly Distributed Multi-Walled Carbon Nanotube/Polymer Composites." Advanced Materials Research 548 (July 2012): 123–27. http://dx.doi.org/10.4028/www.scientific.net/amr.548.123.

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A three-dimensional computational model based on the finite element method was developed to predict the thermal properties of randomly distributed multi-walled carbon nanotube (MWCNT)/polymer composites. The numerical results agree very well with the experimental data for MWCNT/epoxy composites with the MWCNT loading below ~10 vol% at the interfacial thermal resistance of ~1.0×10-8 m2K/W, which may give insight into the relationship between the thermal behavior of MWCNT-matrix interfaces and the thermal conductivity of composites. This model is also a useful tool to evaluate the effects of MWCNT-matrix interfacial thermal resistance, volume fraction, thermal conductivity and diameter of MWCNTs on the thermal conductivity of other types of MWCNT/ polymer composites.

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Stankevich, Stanislav, Olga Bulderberga, Sergejs Tarasovs, Daiva Zeleniakiene, Maria Omastova, and Andrey Aniskevich. "Electrical Conductivity of Glass Fiber-Reinforced Plastic with Nanomodified Matrix for Damage Diagnostic." Materials 14, no. 16 (August 10, 2021): 4485. http://dx.doi.org/10.3390/ma14164485.

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The electrical conductivity of glass fiber-reinforced plastic (GFRP) with epoxy matrix modified by multiwall carbon nanotubes (MWCNT) was studied. The electrical conductivity of nanomodified lamina and multi-layered GFRP was investigated on several levels using a structural approach. Components of the electrical conductivity tensor for unidirectional-reinforced monolayer were calculated similarly as in micromechanics using the conductivity of the nanomodified matrix. The electrical conductivity of multilayer composite was calculated using laminate theory and compared with values measured experimentally for various fiber orientation angles. Calculated and experimental data were in good agreement. The voltage distribution measured throughout the laminate allowed detecting the damage in its volume. The electrode network located on the laminate surface could determine the location, quantification, and geometry of the damage in the GFRP lamina modified with MWCNT. Experimental and calculated electrical resistance data for GFRP double-cantilever beam specimens were investigated in Mode I interlaminar fracture toughness test. Results demonstrate that electrical resistance could be successfully used for the diagnostic of the crack propagation during interlaminar fracture of the MWCNT-modified GFRP.

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Shaari, N. S., M. H. Ismail, A. Jumahat, M. Zainudin, M. F. A. Manap, and N. Shaari. "Thermal Conductivity of Copper Matrix Composites Reinforced with Multi-wall Carbon Nanotubes." Journal of Physics: Conference Series 2051, no. 1 (October 1, 2021): 012048. http://dx.doi.org/10.1088/1742-6596/2051/1/012048.

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Abstract Carbon nanotubes (CNTs) reinforced with metal matrix composites (MMCs) have attracted an increasing interest due to their promising properties. One of the challenges in metal matrix-CNTs composites research is producing a uniform dispersion of CNTs. A poor dispersion of CNTs within the matrix, attributed to strong CNTs entanglement caused by Van der Waals forces. In this study, Cu/CNTs composites have been successfully fabricated by the powder metallurgy (PM) route. The thermal conductivity of Cu/CNTs composites showed that the thermal conductivity decreased after the incorporation of CNTs. The analysis revealed that the interfacial thermal resistance between the Cu matrix and CNTs plays a significant role in determining the thermal conductivity performances. Besides, the influences of porosity and distribution of CNTs also affected the thermal conductivity results.

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Wieczorek, Jakub, Tomasz Maciąg, Karolina Kowalczyk, and Damian Migas. "Evaluation of thermal properties of MMCp composites with silver alloy matrix." Journal of Thermal Analysis and Calorimetry 142, no. 1 (May 13, 2020): 175–82. http://dx.doi.org/10.1007/s10973-020-09741-5.

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Abstract Silver, silver alloys, and composites with silver matrix are used mainly as electric contacts, circuit-breakers, and slide bearings. Contacts working conditions require as high as possible thermal and electrical conductivity, wear resistance during electric arc work, low susceptibility to tacking, and chemical stability. Unreinforced silver alloys do not meet those expectations, hence increasing interest in metal matrix composites. Reinforcing with ceramic particles improves tribological wear resistance and minimizes formability of silver alloys. At the same time, introduction of ceramic particles decreases thermal and electrical conductivity. In this paper, manufacturing method of silver-based composites reinforced with particles Al2O3, SiC, and glassy carbon was described. Composites were subjected to differential thermal analysis. Furthermore, thermal diffusivity measurements using laser flash method, as well as measurements of linear thermal expansion coefficient using dilatometric method were performed in order to determine heat conductivity of the prepared composites.

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Tang, Jin, Ke Xin Chen, and C. S. Fu. "Preparation and Properties of β-Si₃N₄/Epoxy Matrix Composite." Key Engineering Materials 336-338 (April 2007): 1350–52. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.1350.

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Thermally conducting, but electrically insulating, polymer-matrix composites exhibiting low dielectric constant are needed for electronic packaging. For developing such composites, this work used silicon nitride particles as fillers and epoxy as matrix. The thermal conductivity of Si3N4 particles epoxy-matrix composites was increased by up to 31.4 times than that of neat polymer by silane surface treatment of the particles prior to composites fabrication. The increase in thermal conductivity is due to decrease in the filler-matrix thermal contact resistance through the improvement of the interface between matrix and particles. At 45.4 vol. % silane-treated Si3N4 particles only, the thermal conductivity of epoxy-matrix composites reached 9.72W/ (m*K). The dielectric constant was also low (up to 5.0 at 1 MHz). However, Si3N4 addition caused the flexural strength and ductility to decrease from the values of the neat polymer.

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10

Garnier, B., and F. Danes. "Design of High Thermal Conductivity Particle Filled Polymer Using Effective Thermal Conductivity Models." Materials Science Forum 714 (March 2012): 21–24. http://dx.doi.org/10.4028/www.scientific.net/msf.714.21.

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The context of this work is the enhancement of the thermal conductivity of polymer by adding conductive particles. It will be shown how we can use effective thermal conductivity models to investigate effect of various factors such as the volume fraction of filler, matrix thermal conductivity, thermal contact resistance, and inner diameter for hollow particles. Analytical models for lower bounds and finite element models will be discussed. It is shown that one can get some insights from effective thermal conductivity models for the tailoring of conductive composite, therefore reducing the amount of experimental work.

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Bodnárová, Lenka, Jitka Peterková, Jiri Zach, and Kateřina Sovová. "Determination of Thermal Conductivity on Lightweight Concretes." Key Engineering Materials 677 (January 2016): 163–68. http://dx.doi.org/10.4028/www.scientific.net/kem.677.163.

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A range of testing methods were used to study the potential structural changes as a result of the effects of high temperatures on lightweight types of concrete developed above all for fire resistant structures. One such test for monitoring changes in concrete structures is the non-stationary determination of the coefficient of thermal conductivity using the hot wire method. The matrix structure progressively collapses as a result of the effects of high temperatures on the concrete structure ́s surface because erosion takes place of the matrix and aggregate porous structures. The degradation of the porosity of the concrete results in the deterioration of its thermal insulating properties. This paper assesses the dependence of the thermal conductivity coefficient of lightweight concretes on temperature and determines the potential occurrence of structural changes in the lightweight concrete matrix. The results were verified using other methods to determine the concrete ́s resistance to thermal load.

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12

Aung, Zaw Ye, Pavel Prosuntsov, and Sergey Reznik. "Influence of single-walled carbon nanotubes’ diameter and length on the thermal conductivity of polymer composites." MATEC Web of Conferences 224 (2018): 03018. http://dx.doi.org/10.1051/matecconf/201822403018.

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Physical properties of composite materials can be improved by carbon nanotubes (CNTs). However, the thermal resistance between the polymer matrix and CNT at nanoscale can result in lower thermal conductivity. The paper analyses influence of CNTs’ diameter and length on effective thermal conductivity in epoxy-based composites. It analyses the effect of the diameters, lengths and volumetric fraction of CNT on composites’ thermal conductivity.

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13

Cui, Kunkun, Yingyi Zhang, Tao Fu, Jie Wang, and Xu Zhang. "Toughening Mechanism of Mullite Matrix Composites: A Review." Coatings 10, no. 7 (July 14, 2020): 672. http://dx.doi.org/10.3390/coatings10070672.

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Mullite has high creep resistance, low thermal expansion coefficient and thermal conductivity, excellent corrosion resistance and thermal shock resistance, and plays an important role in traditional ceramics and advanced ceramic materials. However, the poor mechanical properties of mullite at room temperature limit its application. In order to improve the strength and toughness of mullite, the current research focuses on the modification of mullite by using the second phase. The research status of discontinuous phase (particle, whisker, and chopped fiber) and continuous fiber reinforced mullite matrix composites is introduced, including preparation process, microstructure, and its main properties. The reinforcement mechanism of second phase on mullite matrix composites is summarized, and the existing problems and the future development direction of mullite matrix composites are pointed out and discussed.

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14

Abyzov, A. M., S. V. Kidalov, and F. M. Shakhov. "Filler-matrix thermal boundary resistance of diamond-copper composite with high thermal conductivity." Physics of the Solid State 54, no. 1 (January 2012): 210–15. http://dx.doi.org/10.1134/s1063783412010027.

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15

Mileiko, S. T., and A. A. Khvostunkov. "Strength, cracking resistance, and electrical conductivity of the carbon fiber-carbide matrix composite." Mechanics of Composite Materials 27, no. 1 (1991): 42–47. http://dx.doi.org/10.1007/bf00630717.

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Bui, Khoa, and Dimitrios V. Papavassiliou. "Heat Transfer in Nanocomposites with Monte-Carlo Simulations." Defect and Diffusion Forum 312-315 (April 2011): 177–82. http://dx.doi.org/10.4028/www.scientific.net/ddf.312-315.177.

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Carbon nanotubes (CNTs) have been suggested to be reinforcement fillers in a variety of composite materials due to their exceptional electrical, thermal and mechanical properties. In terms of thermal properties, incorporating CNTs into a polymer matrix should increase the effective thermal conductivity of the resulting composite. However, the presence of resistance to the transfer of heat at the CNT-polymer interface, known as the Kapitza resistance, results in underperformance of CNT nanocomposites, in terms of thermal properties. In this work, we use Monte Carlo simulations to calculate the effective thermal conductivity of CNT nanocomposites taking into account the Kapitza resistance, as well as the effective thermal conductivity for different inclusion geometries (sphere, cylinder and parallelepiped). The effect of the dispersion pattern of the nano-inclusions is also investigated. Finally, comparing the calculated thermal conductivity from the simulations to experiments, the methodology can be used to calculate the Kapitza resistance of such systems.

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17

Kausar, A. "Advances in Carbon Fiber Reinforced Polyamide-Based Composite Materials." Advances in Materials Science 19, no. 4 (December 1, 2019): 67–82. http://dx.doi.org/10.2478/adms-2019-0023.

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AbstractCarbon fiber has been used to reinforce both aliphatic and aromatic polyamides. Aliphatic polyamide is known as nylon and aromatic polyamide is often referred to as aramid. Among aliphatic polyamides, polyamide 6, polyamide 6,6, polyamide 11, polyamide 12, and polyamide 1010 have been used as matrices for carbon fiber. Factors affecting the properties of polyamide/carbon fiber composites are: fiber amount, fiber length, fiber orientation, matrix viscosity, matrix-fiber interactions, matrix-fiber adhesion, and conditions encountered during manufacturing processes. This article presents a state-of-the-art review on polyamide/carbon fiber composites. Polyamide/carbon fiber composites are lightweight and exhibit high strength, modulus, fatigue resistance, wear resistance, corrosion resistance, gear, electrical conductivity, thermal conductivity, chemical inertness, and thermal stability. Incorporation of oxidized or modified carbon fiber and nanoparticle modified carbon fiber into polyamide matrices have been found to further enhance their physical properties. Applications of polyamide/carbon fiber composites in aerospace, automobile, construction, and other industries have been stated in this review. To fully exploit potential of polyamide/carbon fiber composites, concentrated future attempts are needed in this field.

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Yuan, Jia Wei, Kui Zhang, Xing Gang Li, Ting Li, Yong Jun Li, Ming Long Ma, Guo Liang Shi, Meng Li, and Lin Lai. "Effect of Solute Atoms on the Thermal Property of Mg Alloys." Materials Science Forum 817 (April 2015): 319–24. http://dx.doi.org/10.4028/www.scientific.net/msf.817.319.

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The reason for the distinct difference in the thermal conductivities of different series of Mg alloys was investigated.The crystallographic lattice parameter and the thermal conductivity of Mg–Zn, Mg–Al, and Mg–Gd binary alloys, which all contain the same atomic percentage of the solutes were measured. The Mg–Zn alloys exhibited the highest thermal conductivity and the smallest lattice distortion, and Mg–Gd alloys exhibited lowest thermal conductivity and largest lattice distortion, respectively. Results indicate that the thermal conductivity of the Mg alloys depends on the difference in atomic radius of the solute and matrix atoms. Therefore, the reason for the Mg-7Gd-5Y-0.5Nd-0.5Zr alloy components have excellent thermal resistance is the serious lattice distortion caused by the significant difference in the atomic radius between the solute and matrix atoms.

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Namsone, Eva, Genadijs Sahmenko, Elvija Namsone, and Aleksandrs Korjakins. "THERMAL CONDUCTIVITY AND FROST RESISTANCE OF FOAMED CONCRETE WITH POROUS AGGREGATE." Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference 3 (June 15, 2017): 222. http://dx.doi.org/10.17770/etr2017vol3.2625.

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The paper reports a study, which was carried out to examine thermal and frost resistance properties of foamed concrete (FC) with porous aggregate (expanded glass (EG) granules and cenospheres). By adding lightweight and porous aggregate to the FC mixture, it is possible to improve important physical, mechanical, and thermal properties of the prepared FC specimens. In the framework of this study the coefficient of thermal conductivity and frost resistance of hardened FC samples were determined. The structure of FC matrix and used aggregates were characterised by using a method of optical microscopy.

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Chen, Yutong, Yan Han, Wuqiang Yang, and Kun Li. "A New Iterative Algorithm Based on Correction of Sensitivity Matrix for Electrical Resistance Tomography." Mathematical Problems in Engineering 2019 (December 28, 2019): 1–15. http://dx.doi.org/10.1155/2019/6384132.

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Electrical resistance tomography (ERT) is used to reconstruct the resistance/conductivity distribution. Usually, a uniform distribution is assumed as the initial condition to obtain a generic sensitivity matrix, which may be very different from a theoretical sensitivity matrix, resulting in a large error. The aim of this study is to analyse the difference between a generalized sensitivity matrix and a theoretical sensitivity matrix and to improve image reconstruction. The effect of the generic sensitivity matrix and theoretical sensitivity matrix on image reconstruction is analyzed. The error caused by the use of the generic sensitivity matrix is estimated. To reduce the error, an improved iterative image reconstruction algorithm is proposed, which is based on calculation of the error between the generic sensitivity matrix and the theoretical sensitivity matrix, and a correction coefficient with a penalty. During the iterative process, the resistivity distribution and sensitivity matrix are alternatively corrected. Simulation and experimental results show that the proposed algorithm can improve the quality of images, e.g., of two-phase distributions.

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Zhang, Duanwei, Fusheng Liu, Sheng Wang, Mengxi Yan, Xin Hu, and Mengying Xu. "D-GQDs Modified Epoxy Resin Enhances the Thermal Conductivity of AlN/Epoxy Resin Thermally Conductive Composites." Polymers 13, no. 23 (November 24, 2021): 4074. http://dx.doi.org/10.3390/polym13234074.

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This article proposes a method of increasing thermal conductivity (λ) by improving the λ value of a matrix and reducing the interfacial thermal resistance between such matrix and its thermally conductive fillers. D-GQDs (graphene quantum dots modified by polyetheramine D400) with a π–π-conjugated system in the center of their molecules, and polyether branched chains that are rich in amino groups at their edges, are designed and synthesized. AlN/DG-ER (AlN/D-GQDs-Epoxy resin) thermally conductive composites are obtained using AlN as a thermally conductive and insulating filler, using D-GQDs-modified epoxy resin as a matrix. All of the thermal conductivity, electrically insulating and physical–mechanical properties of AlN/DG-ER are investigated in detail. The results show that D-GQDs linked to an epoxy resin by chemical bonds can increase the value of λ of the epoxy–resin matrix and reduce the interfacial thermal resistance between AlN and DG-ER (D-GQDs–epoxy resin). The prepared AlN/DG-ER is shown to be a good thermally conductive and insulating packaging material.

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Hamdi, Khalil, Zoheir Aboura, Walid Harizi, and Kamel Khellil. "Structural health monitoring of carbon fiber reinforced matrix by the resistance variation method." Journal of Composite Materials 54, no. 25 (April 23, 2020): 3919–30. http://dx.doi.org/10.1177/0021998320921476.

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In this work, electrical resistance change method is used for carbon fiber reinforced thermoplastic polymers damage monitoring. The electrical resistance variation could be an interesting complementary to existing/classical damage monitoring methods. It is extremely attributed to electrical conductivity of composite material and it appears that enhancing the conductivity of materials, by the use of conductive nanofillers in our case, improves their sensitivity to mechanical loading. Carbon fiber reinforced thermoplastic polymers with different nanofillers types and concentrations were manufactured and tested in tensile loading. Concentration of 0 and 8 wt% of carbon black and 2.5 wt% of carbon nanotubes were used with Polyamide 6 sheets as matrix. Nanofillers weakening effect was discussed according to their concentrations and types. The acoustic emission, digital image correlation and in-situ microscopy were also recorded during testing. A correlation between all these signals and the evolution of the electrical resistance of the composites during the tensile loading was performed. It was found that CB enhances sensitivity of carbon fiber reinforced thermoplastic polymers to damage detection, especially delamination. For the carbon nanotubes, results are less promising. A discussion is held about the nanofillers concentration influence.

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23

Du, Fei-Peng, Hao Tang, and De-Yong Huang. "Thermal Conductivity of Epoxy Resin Reinforced with Magnesium Oxide Coated Multiwalled Carbon Nanotubes." International Journal of Polymer Science 2013 (2013): 1–5. http://dx.doi.org/10.1155/2013/541823.

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Magnesium oxide coated multiwalled carbon nanotubes (MgO@MWNT) were fabricated and dispersed into epoxy matrix. The microstructures of MgO@MWNT and epoxy/MgO@MWNT nanocomposites were characterized by TEM and SEM. Electrical resistivity and thermal conductivity of epoxy nanocomposites were investigated with high resistance meter and thermal conductivity meter, respectively. MgO@MWNT has core-shell structure with MgO as shell and nanotube as core, and the thickness of MgO shell is ca. 15 nm. MgO@MWNT has been dispersed well in the epoxy matrix. MgO@MWNT loaded epoxy nanocomposites still retain electrical insulation inspite of the filler content increase. However, thermal conductivity of epoxy was increased with the MgO@MWNT content increasing. When MgO@MWNT content reached 2.0 wt.%, thermal conductivity was increased by 89% compared to neat epoxy, higher than that of unmodified MWNT nanocomposites with the same loading content.

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Almasri, Atheer M. "Predicting the thermal conductivity of polypropylene-multiwall carbon nanotubes using the Krenchel model." Science and Engineering of Composite Materials 25, no. 2 (March 28, 2018): 383–88. http://dx.doi.org/10.1515/secm-2016-0032.

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AbstractThe thermal conductivity of particulate composite models is well documented in the literature. This paper attempts to fit the experimental data for the thermal conductivity of polymer nanocomposites to a three-phase Krenchel model. The use of this model is applicable for structures that consist of a polymer matrix, a nanofiller, and an interfacial layer around the nanoparticles. The effect of Kapitza’s thermal resistance is implemented in the model along with the assumption that the nanofillers are cylindrical and well connected to each other; however, no parameters related to any type of dispersants or the dispersion techniques are stated in the model. The results of the three-phase Krenchel model were validated using the experimental data of thermal conductivity of multiwall carbon nanotubes embedded in polypropylene matrix nanocomposites. It was found that the model was in good agreement with the experimental thermal conductivity data. Moreover, the results from the model showed that the filler geometrical packing factor was 0.75; consequently, the carbon nanotubes formed bundles of several cylindrical tubes. The length of the interface between the nanotubes and the polymer matrix was around 1 Å. Finally, the thermal conductivity of the composite bundle cylinder was 21.63 W/(m K).

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Zhao, Lei, Chen Gao, Lin Yuan, Chin San Wu, Xiao Hua Liu, and Chi Hui Tsou. "Electrical Conductivity and Hydrophobicity of Modified Graphene / Polyvinyl Alcohol Composite Films." Materials Science Forum 1003 (July 2020): 213–18. http://dx.doi.org/10.4028/www.scientific.net/msf.1003.213.

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Modified graphene (MG) incorporated into a matrix of polyvinyl alcohol (PVA) were prepared by a hydrothermal method and ultrasonic dispersion. The effect of high MG content on the properties of composite films was studied. Due to the chemical reaction between MG and PVA, the water resistance and electrical conductivity were improved. The properties of new film and the possibility of its application as conductivity materials were discussed.

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Sugio, Kenjiro, Rio Yamada, Yong Bum Choi, and Gen Sasaki. "Effect of the Interfacial Thermal Resistance on Effective Thermal Conductivity of Al/SiC Particle-Dispersed Composites." Materials Science Forum 879 (November 2016): 1889–94. http://dx.doi.org/10.4028/www.scientific.net/msf.879.1889.

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Steady state thermal conductivity measuring device was designed to measure the effective thermal conductivity of composites. Computer simulations of thermal conduction revealed that the designed device over estimates the effective thermal conductivity, and the correction coefficient was suggested. With this designed device, the effective thermal conductivities of Al/SiC particle-dispersed composites were measured by changing the size of SiC particles from 0.3 μm to 3 μm. The critical element size which could determine the optimal size of reinforcements have been suggested, and validity of the critical element size for Al/SiC composites was confirmed. The thermal conductivity of the composites including small SiC particles was degraded by the interfacial thermal resistance between the matrix and the reinforcement. On the other hand, the thermal conductivity of the composites including large SiC particles was not affected by the interfacial thermal resistance. These results suggest that consideration of the critical element size is valid.

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Ouyang, Qiu Bao, H. L. Gu, W. L. Wang, Di Zhang, and Guo Ding Zhang. "Friction and Wear Properties of Aluminum Matrix Composites and its Application." Key Engineering Materials 351 (October 2007): 147–50. http://dx.doi.org/10.4028/www.scientific.net/kem.351.147.

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Friction and wear properties of aluminum matrix composites are studied, including brake speed, brake pressure, and surface temperature etc. A conclusion can be drawn that SiC particle reinforced aluminum matrix composites are of stable friction coefficient, high thermal conductivity, and excellent wear-resistance. Hubs of motorcycle with brake rings of Al/SiC composites were manufactured and exhibited an excellent braking performance.

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PADHI, PRAKASH C., GOURI S. TRIPATHI, and PRASANTA K. MISRA. "THEORY OF MAGNETO RESISTANCE OF AMORPHOUS SEMICONDUCTORS." International Journal of Modern Physics B 23, no. 22 (September 10, 2009): 4579–87. http://dx.doi.org/10.1142/s0217979209053461.

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We propose a simple theory to explain the anomalous magneto resistance of amorphous semiconductors in the hopping regime. We derive an expression for the magneto resistance (Δρ/ρ0), in this regime by using a reinterpretation of the effective electronic mass, velocity, and lifetime based on the density matrix approach and a three-site jump probability in topologically disordered systems. Our theory accounts for the experimental observation of (Δρ/ρ0) for low magnetic fields at room temperature and below and supports Mott's T-1/4 for the variable range hopping of electrical conductivity.

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Hao, Xiang Yang, Xiao Ying Hua, Guo Sheng Gai, and Jian Lu. "Preparing ACB/UHMWPE Composite by PCS Process and its Electric Resistance-Temperature Behavior." Advanced Materials Research 826 (November 2013): 223–27. http://dx.doi.org/10.4028/www.scientific.net/amr.826.223.

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Composite particles with ultra-high molecular polyethylene (UHMWPE) matrix core and acetylene black (ACB) shell were produced by particle composite system (PCS), and molded into conductive polymer composites. Morphology of these composite particles was investigated by SEM. Matrix particles were coated by ACB nanoparticles very well. Conductive networks of ACB in polymer composites were seen by SEM. The results of electrical behavior study show that the polymer composites exhibit low percolation threshold and its electric conductivity is less affected by temperature due to unusual ACB distribution. Related mechanism is discussed.

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Liu, Xiao Xiao, Qiang Xu, and Hong Nian Cai. "Thermal Conductivity of Sm₂Zr₂O₇-Carbon Nanotube Composite." Advanced Materials Research 105-106 (April 2010): 398–402. http://dx.doi.org/10.4028/www.scientific.net/amr.105-106.398.

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CNT (carbon nanotube) was purified by acid washing method and then dispersed in alcohol. Sm2Zr2O7-CNT composite powders containing different amounts of CNT were synthesized by corprecipitation method and hot-press sintering were selected to prepare the composites. The density and thermal conductivity of the samples were tested. The micro-morphology and phase structure of composites were characterized by field emission scanning electron microscope and X-ray diffraction, respectively. Based on these experiments and theoretical analyses, the influences of carbon nanotube on the micro-morphology, phase structure and thermal conductivity of Sm2Zr2O7-CNT composite were revealed. Results showed that the carbon nantube uniformly dispersed in Sm2Zr2O7 matrix and the thermal conductivity of composites varied with the different amounts of CNT. In this article, the variation of thermal conductivity can be explained by the comprehensive evaluation of Sm2Zr2O7, CNT, pore and the heterogeneous interfaces thermal resistance between matrix and additives.

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Novikov, N. V., A. L. Maystrenko, V. I. Kushch, and S. A. Ivanov. "Quality rating of a metal matrix-diamondcomposite from its thermal conductivity and electric resistance." Mechanics of Composite Materials 42, no. 3 (May 2006): 253–62. http://dx.doi.org/10.1007/s11029-006-0035-2.

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Dobri, A., and T. D. Papathanasiou. "A Multi-Scale, Semi-Analytical Model for Transient Heat Transfer in a Nano-Composite Containing Spherical Inclusions." Eurasian Chemico-Technological Journal 21, no. 2 (June 30, 2019): 101. http://dx.doi.org/10.18321/ectj819.

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This paper presents a semi-analytical model for transient heat conduction in a composite material reinforced with small spherical inclusions. Essential to the derivation of the model is the assumption that the size of the inclusions is much smaller than the length scale characterizing the macroscopic problem. An interfacial thermal resistance is also present between the two phases. During heating, the inclusions are treated as heat sinks within the matrix, with the coupling provided by the boundary conditions at the surface of the embedded particles. Application of Duhamel’s Theorem at the particle scale provides the local relationship between the temperature profile in a particle and the matrix that surrounds it. A simple spatial discretization at the macro-scale leads to an easily solvable system of coupled Ordinary Differential Equations for the matrix temperature, particle surface temperature and a series of ψ-terms related to the heat exchange between phases. The interfacial thermal resistance between the two phases can lead to the particle temperature lagging behind that of the surrounding matrix. The resulting transient response of the matrix temperature cannot be reproduced by a material with a single effective thermal conductivity. In the case where transient methods are used to determine effective thermal conductivity, this transient response may introduce errors into the measurement.

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Coman, Gelu, Gabriel-Bogdan Carp, Ion Ion, Alina Ceoromila, and Nicusor Baroiu. "Materiale compozite pe baza de deseuri de beton celular autoclavizat si rasina poliesterica nesaturata." Materiale Plastice 56, no. 1 (March 30, 2019): 256–60. http://dx.doi.org/10.37358/mp.19.1.5162.

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This paper presents an experimental study on the potential use of new type of composite as insulation material. The composite material (AACW-UPR) was synthesised through mixture between the Autoclaved Aerated Concrete Waste (AACW) as filler and Unsaturated Polyester Resin (UPR) as matrix. Several samples of the composite material with different UPR concentrations (50 and 70 vol.%) and different AACW particle size (0.2-1 mm, 1.5-2.5 mm, 3-6 mm) were prepared. The thermal behaviour and the water absorption capacity of the AACW-UPR composite materials were studied. Also, the influence of water absorption capacity on thermal resistance and thermal conductivity was studied. During the investigations we noticed the following: good chemical compatibility between the AACW particles and the UPR matrix; a decrease in thermal conductivity for samples with 50 vol.% UPR and inserted particles size between 3-6 mm and an increase in water absorption capacity with the increase in the filler content in the matrix. The increasing water absorption capacity determined a decrease in thermal resistance and a reduction of the composite features as insulating material.

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Zou, Cunlei, Zongning Chen, Enyu Guo, Huijun Kang, Guohua Fan, Wei Wang, Rengeng Li, Siruo Zhang, and Tongmin Wang. "A nano-micro dual-scale particulate-reinforced copper matrix composite with high strength, high electrical conductivity and superior wear resistance." RSC Advances 8, no. 54 (2018): 30777–82. http://dx.doi.org/10.1039/c8ra06020g.

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A nano Cu₅Zr and micro ZrB₂ dual-scale particulate-reinforced copper matrix composite is prepared by in situ synthesis and heat treatment, which has high strength, high electrical conductivity and superior wear resistance.

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Badrul, Farah, Khairul Anwar Abdul Halim, MohdArif Anuar Mohd Salleh, Azlin Fazlina Osman, Nor Asiah Muhamad, Muhammad Salihin Zakaria, Nurul Afiqah Saad, and Syatirah Mohd Noor. "The Influence of Compounding Parameters on the Electrical Conductivity of LDPE/Cu Conductive Polymer Composites (CPCs)." Journal of Physics: Conference Series 2080, no. 1 (November 1, 2021): 012008. http://dx.doi.org/10.1088/1742-6596/2080/1/012008.

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Abstract Low-linear density (LDPE) and copper (Cu) were used as main polymer matrix and conductive filler in order to produce electrically conductive polymer composites (CPC). The selection of the matrix and conductive filler were based on their due to its excellence properties, resistance to corrosion, low cost and electrically conductive. This research works is aimed to establish the effect of compounding parameter on the electrical conductivity of LDPE/Cu composites utilising the design of experiments (DOE). The CPCs was compounded using an internal mixer where all formulations were designed by statistical software. The scanning electron micrograph (SEM) revealed that the Cu conductive filler had a flake-like shape, and the electrical conductivity was found to be increased with increasing filler loading as measured using the four-point probe technique. The conductivity data obtained were then analysed by using the statistical software to establish the relationship between the compounding parameters and electrical conductivity where it was found based that the compounding parameters have had an effect on the conductivity of the CPC.

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Savostyanov, George, Michael Slepchenkov, Dmitriy Shmygin, and Olga Glukhova. "Specific Features of Structure, Electrical Conductivity and Interlayer Adhesion of the Natural Polymer Matrix from the Layers of Branched Carbon Nanotube Networks Filled with Albumin, Collagen and Chitosan." Coatings 8, no. 11 (October 24, 2018): 378. http://dx.doi.org/10.3390/coatings8110378.

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This paper considers the problem of creating a conductive matrix with a framework made of carbon nanotubes (CNTs) for cell and tissue engineering. In silico investigation of the electrical conductivity of the framework formed by T-junctions of single-walled carbon nanotubes (SWNTs) (12, 12) with a diameter of 1.5 nm has been carried out. A numerical evaluation of the contact resistance and electrical conductivity of seamless and suture T-junctions of SWCNTs is given. The effect of the type of structural defects in the contact area of the tubes on the contact resistance of the T-junction of SWCNTs was revealed. A coarse-grained model of a branched SWCNT network with different structure densities is constructed and its electrical conductivity is calculated. A new layered bioconstruction is proposed, the layers of which are formed by natural polymer matrixes: CNT-collagen, CNT-albumin and CNT-chitosan. The energy stability of the layered natural polymer matrix has been analyzed, and the adhesion of various layers to each other has been calculated. Based on the obtained results, a new approach has been developed in the formation of 3D electrically conductive bioengineering structures for the restoration of cell activity.

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Liang, Weijie, Tiehu Li, Xiaocong Zhou, Xin Ge, Xunjun Chen, Zehua Lin, Xiaoyan Pang, and Jianfang Ge. "Globular Flower-Like Reduced Graphene Oxide Design for Enhancing Thermally Conductive Properties of Silicone-Based Spherical Alumina Composites." Nanomaterials 10, no. 3 (March 18, 2020): 544. http://dx.doi.org/10.3390/nano10030544.

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The enhancement of thermally conductive performances for lightweight thermal interface materials is a long-term effort. The superb micro-structures of the thermal conductivity enhancer have an important impact on increasing thermal conductivity and decreasing thermal resistance. Here, globular flower-like reduced graphene oxide (GFRGO) is designed by the self-assembly of reduced graphene oxide (RGO) sheets, under the assistance of a binder via the spray-assisted method for silicone-based spherical alumina (S-Al2O3) composites. When the total filler content is fixed at 84 wt%, silicone-based S-Al2O3 composites with 1 wt% of GFRGO exhibit a much more significant increase in thermal conductivity, reduction in thermal resistance and reinforcement in thermal management capability than that of without graphene. Meanwhile, GFRGO is obviously superior to that of their RGO counterparts. Compared with RGO sheets, GFRGO spheres which are well-distributed between the S-Al2O3 fillers and well-dispersed in the matrix can build three-dimensional and isotropic thermally conductive networks more effectively with S-Al2O3 in the matrix, and this minimizes the thermal boundary resistance among components, owning to its structural characteristics. As with RGO, the introduction of GFRGO is helpful when decreasing the density of silicone-based S-Al2O3 composites. These attractive results suggest that the strategy opens new opportunities for fabricating practical, high-performance and light-weight filler-type thermal interface materials.

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Tolypinа, N. M., E. M. Shigareva, M. V. Golovin, and D. S. Shigarev. "APPLICATION OF AGGREGATES OF NEPHELINE BEARING ROCKS IN INCREASED CORROSION RESISTANCE CONCRETE." Vestnik SibADI 15, no. 4 (September 12, 2018): 596–605. http://dx.doi.org/10.26518/2071-7296-2018-4-596-605.

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Introduction. Diffusion of aggressive components of the external environment deeper into the concrete intensively flows through the contact surfaces and between the filler and the cement matrix. Therefore, it is better to apply active fillers that interact with the cement matrix on certain mechanisms for reducing the conductivity of the contact surfaces, which leads to the products durability.Materials and methods. Methods of mechanical testing, x-ray phase analysis, scanning electron microscopy were used for comparative studies of concrete corrosion resistance with the active filler (urtite) and with the inactive one (quartz sand).Results. This research indicates that the urtite filler significantly increases the strength and corrosion resistance of concrete in comparison with the traditional filler with quartz sand. The investigation of the contact zone of cement stone-aggregate with the usage of REM demonstrates that there are no corrosion products in the contact zone of urtite with the cement matrix, while the contact zone of quartz sand and its surface acquires corrosion products represented mainly by gypsum.Discussion and conclusion. The increased corrosion resistance of the fine aggregate concrete through the application of active filler on the basis of urtite provides lower conductivity of the contact surfaces between cement matrix and filler due to the chemical affinity of the rock-forming minerals of nepheline to calcium hydroxide. The additional factor that enhances the self-inhibition of acid corrosion is the formation of the gel-like layer of silica on the surface of nepheline, which inhibits the advancement of hydroxide ions due to the flow of electro-surface processes. Thus, the nepilnameciais fillers are appropriate to apply in concrete, which is used in the conditions of the chemical aggression of high intensity.

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Farooq, Umar, Muhammad Umair Ali, Shaik Javeed Hussain, Muhammad Shakeel Ahmad, Amad Zafar, Usman Ghafoor, and Tayyab Subhani. "Improved Ablative Properties of Nanodiamond-Reinforced Carbon Fiber–Epoxy Matrix Composites." Polymers 13, no. 13 (June 22, 2021): 2035. http://dx.doi.org/10.3390/polym13132035.

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The influence of nanodiamonds (NDs) on the thermal and ablative performance of carbon-fiber-reinforced–epoxy matrix compositeswas explored. The ablative response of the composites with 0.2 wt% and 0.4 wt% NDs was studied through pre-and post-burning morphologies of the composite surfaces by evaluation of temperature profiles, weight loss, and erosion rate. Composites containing 0.2 wt% NDs displayed a 10.5% rise in erosion resistance, whereas composites containing 0.4 wt% NDs exhibited a 12.6% enhancement in erosion resistance compared to neat carbon fiber–epoxy composites. A similar trend was witnessed in the thermal conductivity of composites. Incorporation of composites with 0.2 wt% and 0.4 wt% NDs brought about an increase of 37 wt% and 52 wt%, respectively. The current study is valuable for the employment of NDs in carbon fiber composite applications where improved erosion resistance is necessary.

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HE, YAN, and YUANZHENG TANG. "THERMAL CONDUCTIVITY OF CARBON NANOTUBE/NATURAL RUBBER COMPOSITE FROM MOLECULAR DYNAMICS SIMULATIONS." Journal of Theoretical and Computational Chemistry 12, no. 03 (April 19, 2013): 1350011. http://dx.doi.org/10.1142/s0219633613500119.

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Classical molecular dynamics (MD) simulations are employed to study the thermal conductivity of carbon nanotube/natural rubber (CNT/NR) composite. An aligned CNT/NR system is constructed by atomic potential function and periodic boundary condition and the anisotropic thermal conductivity is predicted in three main directions. The highest thermal conductivity of 80 W/(mK) is predicted along the axial direction of CNT. However, the transverse thermal conductivity perpendicular to the CNT axis is only about 0.6 W/(mK). For obtaining thermal conductivity of randomly oriented CNT/NR composite, an isotropic algorithm is provided from thermal resistance analysis method and results indicate the thermal conductivity improvement of randomly oriented CNT/NR composite is negligible. It is deduced therefore aligning CNTs in NR matrix can be a promising method in thermal management of CNT/NR composite.

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Mosiałek, M., M. Przybyła, M. Tatko, P. Nowak, M. Dudek, and M. Zimowska. "Composite Ag-La0.8Sr0.2MnO3-σ Cathode for Solid Oxide Fuel Cells." Archives of Metallurgy and Materials 58, no. 4 (December 1, 2013): 1337–40. http://dx.doi.org/10.2478/amm-2013-0170.

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Abstract Composite cathodes for solid oxide fuel cells composed of metallic silver dispersed in ceramic (La0:8Sr0:2MnO3-σ) matrix were prepared on the surface of solid electrolyte by two-step procedure. First the matrix of controlled porosity was created by sintering mixture of La0:8Sr0:2MnO3-σ powder with the organic polymer beads then the matrix was saturated with AgNO3 solution and sintered again. Such obtained cathodes showed higher electrical conductivity and lower charge transfer resistance in oxygen reduction reaction in comparison to pure ceramic cathodes

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HONG, YU, XIAOLI CHEN, WENFANG WANG, and YUCHENG WU. "MICROSTRUCTURE AND PROPERTIES OF SiC PARTICLES REINFORCED COPPER BASED ALLOY COMPOSITE." Modern Physics Letters B 27, no. 19 (July 25, 2013): 1341025. http://dx.doi.org/10.1142/s021798491341025x.

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Copper-matrix composites reinforced with SiC particles are prepared by mechanical alloying. The microstructure characteristics, relative density, hardness, tensile strength, electrical conductivity, thermal conductivity and wear properties of the composites are investigated in this paper. The results indicate that the relative density, macro-hardness and mechanical properties of composites are improved by modifying the surface of SiC particles with Cu and Ni . The electrical conductivity and thermal conductivity of composites, however, are not obviously improved. For a given volume fraction of SiC , the Cu / SiC ( Ni ) has higher mechanical properties than Cu / SiC ( Cu ). The wear resistance of the composites are improved by the addition of SiC . The composites with optimized interface have lower wear rate.

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Yang, Xuping, Wenbin Yang, Jinghui Fan, Juying Wu, and Kai Zhang. "Effects of molding on property of thermally conductive and electrically insulating polyamide 6–based composite." Journal of Thermoplastic Composite Materials 32, no. 9 (August 23, 2018): 1190–203. http://dx.doi.org/10.1177/0892705718794792.

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Thermally conductive and electrically insulating polyamide 6 (PA6) matrix quaternary composites were prepared by hot press molding and injection molding, respectively. The quaternary composites were composed of zero-dimensional aluminum oxide particle, one-dimensional silicon carbide whisker, two-dimensional flake graphite, and PA6 resin matrix. Morphology, structure, density, thermal conductivity, volume electrical resistivity, and tensile strength of two types of composites were characterized by scanning electron microscopy, X-ray diffractometer, thermal conductivity tester, high resistance micro-current tester, and tensile tester. The results showed that crystallinity, thermal conductivity, density, and tensile strength of hot press molding samples were superior to those of samples made by injection molding method. This is due to that hot press molding method can provide higher molding pressure and longer annealing time than injection molding. The mechanism could be explained that the performances of the composites were promoted by increasing molding pressure and annealing time.

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Sugio, Kenjiro, Yong-Bum Choi, and Gen Sasaki. "Effect of the Interfacial Thermal Resistance on the Effective Thermal Conductivity of Aluminum Matrix Composites." Journal of the Japan Institute of Metals 81, no. 10 (2017): 467–74. http://dx.doi.org/10.2320/jinstmet.j2017014.

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Sugio, Kenjiro, Yong-Bum Choi, and Gen Sasaki. "Effect of the Interfacial Thermal Resistance on the Effective Thermal Conductivity of Aluminum Matrix Composites." MATERIALS TRANSACTIONS 57, no. 5 (2016): 582–89. http://dx.doi.org/10.2320/matertrans.mc201505.

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Lavrov, I. V., A. A. Kochetygov, V. V. Bardushkin, A. P. Sychev, and V. B. Yakovlev. "Effective Thermal Conductivity of Composites with Contact Thermal Resistance between the Inclusions and the Matrix." Russian Engineering Research 40, no. 8 (August 2020): 622–27. http://dx.doi.org/10.3103/s1068798x20080134.

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Wąsik, Mateusz, and Joanna Karwan-Baczewska. "Copper Metal Matrix Composites Reinforced by Titanium Nitride Particles." Key Engineering Materials 682 (February 2016): 270–75. http://dx.doi.org/10.4028/www.scientific.net/kem.682.270.

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Copper based Metal Matrix Composites are promising materials for electrical and electrotechnical applications such as electronic packaging and contacts, resistance welding electrodes, heat exchangers etc. Introducing the ceramics particles into the copper matrix allows to achieve a higher mechanical properties comparing to pure copper. The literature shows the variety of reinforcement materials are used. The most commonly strengthening phase include: oxides Al2O3,Y2O3, SiO2, carbides SiC, WC, TiC, ZrC, borides TiB2, ZrB2 and others such us volcanic tuff, carbon or intermetalic phases Al-Fe. [1-7]. It is obvious that reinforcement material without TiN leads to decrease the electrical conductivity of copper. Preliminary investigations concerning nanoscale Cu-based composites with TiN particles were presented in papers [10, 11]. Powder metallurgy (PM) process leads to obtain uniform distribution of strengthening phase in matrix. In order to achieve uniform distribution the process parameters such as mixing and selection the sizes of particles must be appropriate selected. The another factor of decreasing the mechanical and electrical properties by using PM route is porosity. Conventional PM process includes pressing and sintering does not always allow to achieve the high density what is one of the main criterion for high electrical conductivity material. The hard ceramic particles in metal matrix which are not deformable make difficult the densification process. In some cases the use of more advanced methods of production is desirable. The use of titanium nitride particles is justified by their high electrical conductivity in compare to the other reinforcement materials.

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Mizerová, Celílie, Ivo Kusák, and Pavel Rovnaník. "ELECTRICAL PROPERTIES OF FLY ASH GEOPOLYMER COMPOSITES WITH GRAPHITE CONDUCTIVE ADMIXTURES." Acta Polytechnica CTU Proceedings 22 (July 25, 2019): 72–76. http://dx.doi.org/10.14311/app.2019.22.0072.

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Construction materials with increased electrical conductivity could be possibly used in health monitoring of structures (stress, deformation, damages), their maintenance or traffic monitoring. The aim of this study was the application of functional filler and its influence on the electrical properties of the alkali-activated fly ash matrix. The graphite powder was added to the reference material in the amount of 2–10 %. Besides the assessment of the critical amount of filler necessary to achieve a percolation threshold in the structure of the composite, the effect on the electrical properties of the matrix (resistance, capacitance, conductivity) was determined. The optimal amount of filler was also determined with respect to the changes in microstructure of the binder and its mechanical properties.

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HUANG, CONGLIANG, YANHUI FENG, XINXIN ZHANG, and GE WANG. "THERMAL CONDUCTIVITY OF NANOPOROUS GLASS ALUMINA FILM AND COMPOSITES." Modern Physics Letters B 28, no. 03 (January 23, 2014): 1450019. http://dx.doi.org/10.1142/s0217984914500195.

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In this paper, cross-plane thermal conductivities of the nanoporous glass alumina film (NGAF) and its composites ( Ag /NGAF, with Ag nanowires embedded in) were measured. And a model was setup to predict the thermal conductivity of the nanoporous material. Results show that the thermal conductivity of the NGAF is about 50 times smaller than that of the ceramic alumina. It is about 0.5 W ⋅ m -1⋅ K -1 and depends on both the pore radius and the porosity. The thermal conductivity of the Ag /NGAF is not larger than that of the NGAF. The contact resistance and the unfilled space between Ag nanowires and the matrix are responsible for that.

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Kwon, Dae Hwan, Thuy Dang Nguyen, Dina V. Dudina, Ji Soon Kim, Young Jin Yum, and Young Soon Kwon. "Properties of Dispersion Strengthened Cu-TiB₂ Nanocomposites Prepared by Spark Plasma Sintering." Solid State Phenomena 119 (January 2007): 63–66. http://dx.doi.org/10.4028/www.scientific.net/ssp.119.63.

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Preparation of titanium diboride reinforced copper matrix composites with high conductivity and mechanical strength was developed based on in situ produced powders. The effect of the titanium diboride content on the mechanical properties of the bulk material produced from the powders by Spark Plasma Sintering technique was studied. Increasing titanium diboride content from 2.5 up to 7.5 wt.% resulted in a 1.5-fold increase in yield strength, tensile strength and hardness and 5-fold increase in wear resistance with only 10% decrease in conductivity.

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Journal articles on the topic 'Conductivity and resistance matrix'

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