scholarly journals Thermal Conductivity and Compaction of GDL-MPL Interfacial Composite Material

2018 ◽  
Vol 165 (7) ◽  
pp. F514-F525 ◽  
Author(s):  
R. Bock ◽  
A. D. Shum ◽  
X. Xiao ◽  
H. Karoliussen ◽  
F. Seland ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Composite Material

The Estimation of Thermal Conductivity for Alumina-Epoxy Composite Material with High Filling Volume Fraction

2014 ◽  
Vol 918 ◽  
pp. 21-26
Author(s):  
Chen Kang Huang ◽  
Yun Ching Leong
Keyword(s):  
Thermal Conductivity ◽  
Composite Material ◽  
Composite Materials ◽  
Physical Model ◽  
Electron Scattering ◽  
Volume Fraction ◽  
Epoxy Composite ◽  
The Matrix ◽  
Transport Theorem ◽  
Good Agreement

In this study, the transport theorem of phonons and electrons is utilized to create a model to predict the thermal conductivity of composite materials. By observing or assuming the dopant displacement in the matrix, a physical model between dopant and matrix can be built, and the composite material can be divided into several regions. In each region, the phonon or electron scattering caused by boundaries, impurities, or U-processes was taken into account to calculate the thermal conductivity. The model is then used to predict the composite thermal conductivity for several composite materials. It shows a pretty good agreement with previous studies in literatures. Based on the model, some discussions about dopant size and volume fraction are also made.

Examination of Microstructure of Cement Composite Material for Renovation of Horizontal Structures

2019 ◽  
Vol 808 ◽  
pp. 103-108
Author(s):  
Lenka Mészárosová ◽  
Vít Černý ◽  
Rostislav Drochytka ◽  
Winfried Malorny
Keyword(s):  
Thermal Conductivity ◽  
Composite Material ◽  
High Temperature ◽  
Surface Temperature ◽  
Cement Composite ◽  
Volume Weight ◽  
Coefficient Of Thermal Conductivity ◽  
New Material ◽  
Properties Of Materials ◽  
Low Volume

Development of new material is focused on modification of properties of materials with silicate binder so that these could be used for renovation of horizontal structures of high-temperature devices and at the same time contribute to reduction of heat transportation of constructions with higher surface temperature (in this case 200 and 500 °C). Main requirements for this material is low volume weight and low coefficient of thermal conductivity. This paper assesses influence of exposition to higher temperatures on microstructure.

THERMAL CONDUCTIVITY AND THERMAL AGING PERFORMANCE OF Sn WITH 0.7 wt.% Cu and VARIOUS GRAPHENE ADDITIONS

2019 ◽  
Vol 27 (06) ◽  
pp. 1950161
Author(s):  
CAIXIA SUN ◽  
FENGYUN ZHANG ◽  
HONGXIA ZHANG ◽  
NIANLONG ZHANG ◽  
SHOUYING LI ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Composite Material ◽  
Composite Materials ◽  
Thermal Aging ◽  
X Ray Diffraction ◽  
Diffraction Intensity ◽  
A Value ◽  
Aging Test ◽  
Accelerated Thermal Aging ◽  
Aging Performance

The effect of graphene content (0.08, 0.16 and 0.33[Formula: see text]wt.%) on the thermal conductivity and thermal aging performance of an Sn based composite material with 0.7[Formula: see text]wt.% Cu and various graphene additions was investigated via X-ray diffraction (XRD), scanning electron microscope (SEM) and accelerated thermal aging test. The XRD results showed that the graphene diffraction intensity was weak (approximately 10∘) due to little content and distribution of the graphene on the surface of the composite materials. After thermal aging testing the diffraction intensity on some crystal planes of the composite materials was enhanced, proving that preferential growth occurs on the crystal plane. SEM results showed that before aging testing no whiskers were generated on the surface of the composite materials. After the accelerated thermal aging at 100∘C for 24[Formula: see text]h, whisker growth became apparent in the composite materials. All the whiskers were located in the grains rather than on the grain boundaries of the composite materials. The highest thermal conductivity was obtained at 0.16[Formula: see text]wt.% graphene addition (indicated as 0.16[Formula: see text]wt.% graphene–0.7[Formula: see text]wt.% Cu/Sn). After the accelerated thermal aging at 100∘C for 24[Formula: see text]h, the bamboo-shaped whiskers with a low aspect ratio grew in large quantities on the surface of the 0.16[Formula: see text]wt.% graphene–0.7[Formula: see text]wt.% Cu/Sn composite material, while when the aging was at 100∘C for 366[Formula: see text]h the thermal conductivity decreased from 67[Formula: see text]W[Formula: see text][Formula: see text][Formula: see text][Formula: see text] to 52[Formula: see text]W[Formula: see text][Formula: see text][Formula: see text][Formula: see text]. When the graphene addition was 0.33[Formula: see text]wt.% (indicated as 0.33[Formula: see text]wt.% graphene–0.7[Formula: see text]wt.% Cu/Sn) the thermal conductivity maintains a value above 59[Formula: see text]W[Formula: see text][Formula: see text][Formula: see text][Formula: see text] after the accelerated thermal aging.

The Effect of Surface Active Substances on the Mechanical Properties of a Copper-Matrix Nanocomposite

2019 ◽  
Vol 945 ◽  
pp. 493-497
Author(s):  
Y. Shchetinin ◽  
Y. Kopylov ◽  
A. Zhirkov
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Composite Material ◽  
Carbon Nanostructures ◽  
Hot Isostatic Pressing ◽  
Copper Matrix ◽  
Planetary Mill ◽  
Preliminary Treatment ◽  
Nanostructured Composite ◽  
The Matrix

The presented work reviews the research in the field of production of nanostructured composite materials based on copper, reinforced with carbon nanostructures. Particular attention is paid to the use of composites with high thermal conductivity as structural materials. The method of manufacturing a composite material based on copper is described in detail: modes of preliminary annealing, pre-pressing, hot isostatic pressing. The characteristics of the matrix and alloying components are given, and also preliminary treatment of copper powder and carbon nanotubes is described. Different mechanisms of component mixing are considered, the process of mechanical alloying in a planetary mill is described in detail, the results of measuring the thermal conductivity of samples are given. The mechanical characteristics of the samples are considered in detail: ultimate strength, yield strength, elongation. The degree of influence of surfactants on the uniformity of the distribution of alloying components and the mechanical properties of the composite material is determined.

Theoretical Considerations on Fibre Reinforced Composites Thermal Conductivity Uncertainties

2015 ◽  
Vol 1128 ◽  
pp. 171-177
Author(s):  
Tudor Mihai Simionescu ◽  
Alina Adriana Minea
Keyword(s):  
Thermal Conductivity ◽  
Composite Material ◽  
Engineering System ◽  
Thermal Expansion Coefficients ◽  
Theoretical Approaches ◽  
Composites Materials ◽  
Expansion Coefficients ◽  
Theoretical Considerations ◽  
Fibre Reinforced Composites ◽  
Properties Of Composites

Thermal conductivity of composites is anisotropic in nature and data about thermal conductivity of resin facilitates to reduce stresses related to shrinkage of composites during cure and mismatch in thermal expansion coefficients. Before conducting experiments to determine thermal conductivity of various composites, knowledge about effect of different parameters influencing thermal conductivity is essential. The increasing use of composites, for various applications, emphasizes its importance/significance in the thermal property analysis of an engineering system. Published literature is rich with investigations of mechanical properties of composites, but fewer publications are focused on thermal properties. Several publications addressing different theoretical approaches for predicting thermal conductivity of composite materials have been noted. Various theoretical approaches are used to yield the thermal conductivity of a composite material so that the heat flow in anisotropic composite material in any direction can be estimated. In this paper few models will be considered and a theoretical study on thermal conductivity uncertainties will be conducted and discussed. The results identified the need and importance of carrying out further investigations on thermal behavior of composites materials.

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