The Hall Carrier Mobility of AgBiTe2-Ag2Te Composite

2001 ◽  
Vol 691 ◽  
Author(s):  
T. Sakakibara ◽  
Y. Takigawa ◽  
K. Kurosawa
Keyword(s):  
Electrical Conductivity ◽  
Composite Material ◽  
Composite Materials ◽  
Hall Coefficient ◽  
Carrier Mobility ◽  
Matrix Phase ◽  
Second Phase ◽  
Temperature Range ◽  
The Matrix ◽  
Van Der Pauw

ABSTRACTWe prepared a series of (AgBiTe2)1−x(Ag2Te)x(0≤×≤1) composite materials by melt and cool down [1]. The Hall coefficient and the electrical conductivity were measured by the standard van der Pauw technique over the temperature range from 93K to 283K from which the Hall carrier mobility was calculated. Ag2Te had the highest mobility while the mobility of AgBiTe2was the lowest of all samples at 283K. However the mobility of the (AgBiTe2)0.125(Ag2Te)0.875composite material was higher than the motility of Ag2Te below 243K. It seems that a small second phase dispersed in the matrix phase is effective against the increased mobility.

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.

scholarly journals Particularities of structure formation of aluminum-copper composite materials manufactured by casting technology

2020 ◽  
pp. 116-121
Author(s):  
V. A. Kalinichenko ◽  
A. S. Kalinichenko ◽  
S. V. Grigoriev
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Structure Formation ◽  
Matrix Material ◽  
Matrix Alloy ◽  
Alloying Elements ◽  
Casting Technology ◽  
The Matrix ◽  
Reinforcing Material ◽  
Copper Composite

To create friction pairs operating in severe working conditions, composite materials are now increasingly used. Composite materials obtained with the use of casting technologies are of interest due to the possibility to manufacture wide range of compositions at low price compared to powder metallurgy. Despite the fact that many composite materials have been sufficiently studied, it is of interest to develop new areas of application and give them the properties required by the consumer. In the present work the composite materials on the basis of silumin reinforced with copper granules were considered. Attention was paid to the interaction between the matrix alloy and the reinforcing phase material as determining the properties of the composite material. The analysis of distribution of the basic alloying elements in volume of composite material and also in zones of the interphases interaction is carried out. The analysis of the possibility of obtaining a strong interphase zone of contact between the reinforcing component and the matrix material without significant dissolution of the reinforcing material is carried out.

Effect of Solution Treatment on Second Phase Dissolution for an Al-9.2Zn-2.0Mg-1.9Cu Alloy

2020 ◽  
Vol 993 ◽  
pp. 321-326
Author(s):  
Hong Wei Liu ◽  
Kai Wen ◽  
Xi Wu Li ◽  
Zhi Hui Li ◽  
Li Zhen Yan ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Solution Temperature ◽  
Second Phase ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
Phase Dissolution ◽  
Solution Treated ◽  
The Matrix

The second phase dissolution of Al-9.2Zn-2.0Mg-1.9Cu alloy conducted by various temperatures of 2h was researched with the help of optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), electrical conductivity and differential scanning calorimetry (DSC) analysis. The results gave rise to the second phase existence of Mg(Zn,Cu,Al)2 and Fe-containing phases in the as-extruded alloy. When the alloy solution treated with a temperature varied from 450°C to 470°C, a small quantity of Mg(Zn,Cu,Al)2 phase still existed in the alloy while its content exhibited a decrement trend with the solution temperature rose. For the alloy solution treated at a temperature of 475°C, Mg(Zn,Cu,Al)2 phase dissolved into the matrix completely while Fe-containing phase still remained. The electrical conductivity of quenched alloy decrease with the solution temperature increase and reached a minimum value at 470°C, and then rose slightly for the solution temperature of 475°C.

Continuous and Discontinuous Recrystallization of 6013 Aluminum Alloy

2013 ◽  
Vol 753 ◽  
pp. 221-224 ◽  
Author(s):  
Krzysztof Sztwiertnia ◽  
Magdalena Bieda ◽  
Anna Korneva
Keyword(s):  
Aluminum Alloy ◽  
Grain Boundaries ◽  
Second Phase ◽  
Sheet Plane ◽  
Temperature Range ◽  
Orientation Mapping ◽  
Second Phase Particles ◽  
The Matrix ◽  
Continuous Recrystallization

In situ orientation mapping using TEM and calorimetric measurements were carried out to investigate the annealing behavior of cold-rolled 6013 aluminum alloy. The recrystallization of the material can be considered to be a number of processes that correspond to two separate stored energy release peaks. In the temperature range of the peak 1, the deformation zones around the large second-phase particles acted as sites for particle-stimulated nucleation. In the matrix, at the same time, some elongation of grains occurred. The elongated matrix grains appeared because of the reduction of the dislocation density and the annihilation of some low-angle grain boundaries between chains of subgrains lying in layers parallel to the sheet plane. The matrix processes in this temperatures range can be considered forms of continuous recrystallization. The matrix high-angle grain boundaries started to migrate at the temperature range of the peak 2. They moved mostly in the direction normal to the sheet plane. Heating of the sample for an appropriate time at those temperatures resulted in the complete discontinuous recrystallization of the material. The recrystallized microstructure was dominated now by elongated grains, which were a few times thicker than those obtained by annealing at the temperatures of the peak 1.

scholarly journals Sintering of composite materials for tool appointment, based on impact diamonds, under high pressure and temperatures

2021 ◽  
Vol 66 (1) ◽  
pp. 47-57
Author(s):  
V. T. Senyut
Keyword(s):  
Silicon Carbide ◽  
Composite Material ◽  
Composite Materials ◽  
Removal Rate ◽  
Structure Type ◽  
Synthetic Diamonds ◽  
The Matrix ◽  
Magnetic Abrasive Polishing ◽  
Metal Matrix Composite Material ◽  
Impact Diamond

The article presents the results of a study of composite materials based on diamond-lonsdaleite abrasive (DLA) and various binders (Fe–Ti mechanocomposite, silicon carbide SiC). A metal-matrix composite material with a multimodal nano- and microlevel structure, characterized by increased adhesion of diamond grains to the binder, is obtained on the basis of impact diamonds and a Fe–Ti nano-mechanical composite. It is shown that the use of impact diamonds in comparison with synthetic diamonds makes it possible to reduce the pressure of thermobaric treatment by 30–50 % at the same sintering temperatures. The use of Fe–Ti–DLA composites in the process of magnetic-abrasive polishing (MAP) makes it possible to increase the removal rate of material based on silicon by 1.5–2 times and reduce the processing time by 30 % compared to ferroabrasive powder (FAP) based on synthetic diamonds. The effect of adding of silicon carbide on the process of obtaining a superhard composite material impact diamond – SiC is investigated. It is found that adding of SiC helps to reduce the defectiveness of the material and increase the homogeneity of its structure in comparison with the material without adding of a binder. In this case, an increase in the content of SiC and Si also leads to an inversion of the structure type of the superhard composite from polycrystalline to matrix. It is found that the additional use of amorphous soot and boron affects the refinement of the matrix structure of the composite material due to the formation of boron carbide and secondary finely dispersed silicon carbide.

scholarly journals Study of tensile strength and morphology of polyester matrix composite materials reinforced Hibiscus tiliaceust bark powder as raw material of rear bumper vehicle

2021 ◽  
Vol 7 (1) ◽  
pp. 085-090
Author(s):  
Sujita Darmo Darmo ◽  
Rudy Sutanto Sutanto
Keyword(s):  
Tensile Strength ◽  
Composite Material ◽  
Composite Materials ◽  
Volume Fraction ◽  
Fibrous Composite ◽  
Natural Fibers ◽  
Alkaline Treatment ◽  
Raw Material ◽  
Soaking Time ◽  
The Matrix

Fibrous composite materials continue to be researched and developed with the long-term goal of becoming an alternative to metal substitutes. Due to the nature of the fiber reinforced composite material, its high tensile strength, and low density compared to metal. In general, the composition of the composite consists of reinforcing fibers and a matrix as the binding material. The potential of natural fibers as a reinforcing composite material is still being developed and investigated. The research that has been done aims to determine the characteristics of the tensile strength of the composite strengthened with Hibiscus tiliaceust bark powder (HTBP) with alkaline NaOH and KOH treatment. The reinforcing material used is HTBP and the matrix is polyester resin, with volume fraction of 5%, 10% and 20% with an alkaline treatment of 5% NaOH and 5% KOH with immersion for 2 hours, 4 hours, 6 hours and 8 hours. Tensile testing specimens and procedures refer to ASTM D3039 standard. The results of this study showed the highest tensile strength of 34.96 MPa in the alkaline treatment of 5% KOH, soaking time of 8 hours with a volume fraction of 10% and the lowest tensile strength of 21.96 MPa of 5% KOH alkaline treatment, soaking time of 6 hours with a volume fraction of 20%. .with 10% volume fraction of 34.96 MPa and the lowest tensile strength was 5% KOH alkaline treatment at 6 hours immersion with 20% volume fraction.

scholarly journals High sound absorption of polyester composites / fiber hemp / nanocellulose for automotive interior materials

2020 ◽  
Vol 2 (2) ◽  
pp. 170-174
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Sound Absorption ◽  
Natural Fiber ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Transmission Loss ◽  
Hemp Fiber ◽  
The Matrix ◽  
Polyester Composite

Human health and environmental comfort are disturbed by the presence of noise, especially in cars, so that effective sound-absorbing materials are currently being developed. To answer the problem of noise in car interiors, polyester composite materials with local hemp fiber and nanocellulose reinforcement were developed. Natural fiber is biodegradable and renewable, and acts as an alternative to the use of synthetic fibers. The method used for the composite material manufacturing process was the casting method. The matrix of the composite material was polyester, while the reinforcement was a combination of local hemp fiber and nanocellulose fiber. Alkalization and non-alkalization processes have been carried out on hemp fiber. The composition of nanocellulose was 0%, 1%, and 3%. The characterization applied in this research were SEM test, FTIR test, sound transmission loss test, and density test. Optimal results were obtained on hemp fiber reinforced polyester composite materials without alkalization and without nanocellulose. Sound transmission loss (STL) was 61.91 dB up to 68.52 dB for the frequency range of 630 Hz to 125 Hz. The standard noise limit on 8-passenger passenger's four-wheeled vehicles is 77-80 dB. Based on the results obtained, the sound absorption is good. The density of this composite material was obtained at 0.989 gram/cm3. This composite material has the potential for developing dashboard material.

scholarly journals PENGEMBANGAN MATERIAL RINGAN SERAT GELAS PADA INDUSTRI KERETA API

2020 ◽  
Vol 19 (3) ◽  
pp. 187-194
Author(s):  
Oki Kurniawan ◽  
Willy Artha Wirawan ◽  
Akbar Zulkarnain
Keyword(s):  
Tensile Strength ◽  
Composite Material ◽  
Composite Materials ◽  
Manufacturing Industry ◽  
Bending Strength ◽  
Transportation Industry ◽  
Fiber Glass ◽  
Railroad Industry ◽  
The Matrix ◽  
Glass Reinforcement

Abstract The use of composite materials has been developed in the railroad transportation industry sector in Indonesia. For example, PT INKA has used composite materials with fiber glass reinforcement. The purpose of this study is to determine the characteristics of tensile strength and bending strength of the composite material so that it can be proposed to be further developed and utilized by the manufacturing industry, especially the railroad industry. In this study, 4 types of matrix variations were examined, namely epoxy, repoxy, polyester, and bhispenol using fiber glass reinforcement. Tensile strength and bending strength tests were performed in accordance with the ASTM D-638 and the ASTM D-790 standards, respectively. The results of this study indicate that the variation of the matrix is very influential on the tensile strength and bending strength of composite materials. Keywords: composite material, glass fiber, tensile strength, bending strength  Abstrak Penggunaan material komposit mulai banyak dikembangkan di sektor industri trasportasi kereta api di Indone-sia. Sebagai contoh, PT INKA sudah menggunakan material komposit dengan penguat serat gelas. Tujuan penelitian ini adalah untuk mengetahui karakteristik kekuatan tarik dan kekuatan bending material komposit agar dapat diusulkan untuk lebih dikembangkan dan dimanfaatkan oleh industri manufaktur, khususnya industri kereta api. Pada penelitian ini digunakan 4 jenis variasi matriks, yaitu epoxy, repoxy, polyester, dan bhispenol dengan menggunakan penguat serat gelas. Pengujian kekuatan tarik menggunakan standar ASTM D-638 dan pengujian bending menggunakan standar ASTM D-790. Hasil studi ini menunjukkan bahwa variasi matriks sangat berpengaruh pada kekuatan tarik maupun kekuatan bending material komposit. Kata-kata kunci: material komposit, serat gelas, kekuatan tarik, kekuatan bending

scholarly journals Mathematical Modeling of Electrical Conductivity of Anisotropic Nanocomposite with Periodic Structure

Mathematics ◽  
2021 ◽  
Vol 9 (22) ◽  
pp. 2948
Author(s):  
Sergey Korchagin ◽  
Ekaterina Pleshakova ◽  
Irina Alexandrova ◽  
Vitaliy Dolgov ◽  
Elena Dogadina ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Composite Materials ◽  
Optical Anisotropy ◽  
Nanocomposite Material ◽  
The Matrix ◽  
Self Similar ◽  
Anisotropic Form ◽  
Shape And Size

Composite materials consisting of a dielectric matrix with conductive inclusions are promising in the field of micro- and optoelectronics. The properties of a nanocomposite material are strongly influenced by the characteristics of the substances included in its composition, as well as the shape and size of inclusions and the orientation of particles in the matrix. The use of nanocomposite material has significantly expanded and covers various systems. The anisotropic form of inclusions is the main reason for the appearance of optical anisotropy. In this article, models and methods describing the electrical conductivity of a layered nanocomposite of a self-similar structure are proposed. The method of modeling the electrical conductivity of individual blocks, layers, and composite as a whole is carried out similarly to the method of determining the dielectric constant. The advantage of the method proposed in this paper is the removal of restrictions imposed on the theory of generalized conductivity associated with the need to set the dielectric constant.

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