Light-colored compound conductive coatings based on CuI: Effect of volume fraction of CuI on morphology and electrical conductivity

2010 ◽  
Vol 68 (3) ◽  
pp. 208-213 ◽  
Author(s):  
Sen Song ◽  
Vijay Mannari
Keyword(s):  
Electrical Conductivity ◽  
Volume Fraction ◽  
Conductive Coatings ◽  
Colored Compound

scholarly journals Elastic wave velocity and electrical conductivity in a brine-saturated rock and microstructure of pores

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Tohru Watanabe ◽  
Miho Makimura ◽  
Yohei Kaiwa ◽  
Guillaume Desbois ◽  
Kenta Yoshida ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Elastic Wave ◽  
Wave Velocity ◽  
High Pressures ◽  
Seismic Velocity ◽  
Volume Fraction ◽  
Elastic Wave Velocity ◽  
Fluid Volume ◽  
Sem Observation ◽  
Wide Aperture

AbstractElastic wave velocity and electrical conductivity in a brine-saturated granitic rock were measured under confining pressures of up to 150 MPa and microstructure of pores was examined with SEM on ion-milled surfaces to understand the pores that govern electrical conduction at high pressures. The closure of cracks under pressure causes the increase in velocity and decrease in conductivity. Conductivity decreases steeply below 10 MPa and then gradually at higher pressures. Though cracks are mostly closed at the confining pressure of 150 MPa, brine must be still interconnected to show observed conductivity. SEM observation shows that some cracks have remarkable variation in aperture. The aperture varies from ~ 100 nm to ~ 3 μm along a crack. FIB–SEM observation suggests that wide aperture parts are interconnected in a crack. Both wide and narrow aperture parts work parallel as conduction paths at low pressures. At high pressures, narrow aperture parts are closed but wide aperture parts are still open to maintain conduction paths. The closure of narrow aperture parts leads to a steep decrease in conductivity, since narrow aperture parts dominate cracks. There should be cracks in various sizes in the crust: from grain boundaries to large faults. A crack must have a variation in aperture, and wide aperture parts must govern the conduction paths at depths. A simple tube model was employed to estimate the fluid volume fraction. The fluid volume fraction of 10−4–10−3 is estimated for the conductivity of 10−2 S/m. Conduction paths composed of wide aperture parts are consistent with observed moderate fluctuations (< 10%) in seismic velocity in the crust.

Investigate of Electrical Conductivity of Shape-Memory Polymer Filled with Carbon Black

2008 ◽  
Vol 47-50 ◽  
pp. 714-717 ◽  
Author(s):  
Xin Lan ◽  
Jin Song Leng ◽  
Yan Ju Liu ◽  
Shan Yi Du
Keyword(s):  
Electrical Conductivity ◽  
Carbon Black ◽  
Shape Memory ◽  
Shape Recovery ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Recovery Process ◽  
Thermomechanical Properties ◽  
Electrically Conductive ◽  
New System

A new system of thermoset styrene-based shape-memory polymer (SMP) filled with carbon black (CB) is investigated. To realize the electroactive stimuli of SMP, the electrical conductivity of SMP filled with various amounts of CB is characterized. The percolation threshold of electrically conductive SMP filled with CB is about 3% (volume fraction of CB), which is much lower than many other electrically conductive polymers. When applying a voltage of 30V, the shape recovery process of SMP/CB(10 vol%) can be realized in about 100s. In addition, the thermomechanical properties are also characterized by differential scanning calorimetery (DSC).

MICROSTRUCTURE AND PROPERTIES OF SiC PARTICLES REINFORCED COPPER BASED ALLOY COMPOSITE

2013 ◽  
Vol 27 (19) ◽  
pp. 1341025 ◽  
Author(s):  
YU HONG ◽  
XIAOLI CHEN ◽  
WENFANG WANG ◽  
YUCHENG WU
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Relative Density ◽  
Volume Fraction ◽  
Copper Matrix ◽  
Matrix Composites ◽  
Wear Properties ◽  
Sic Particles ◽  
Copper Based Alloy

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.

scholarly journals In Situ Doping of Nitrogen in -Oriented Bulk 3C-SiC by Halide Laser Chemical Vapour Deposition

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 410
Author(s):  
Youfeng Lai ◽  
Lixue Xia ◽  
Qingfang Xu ◽  
Qizhong Li ◽  
Kai Liu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Chemical Vapour Deposition ◽  
High Speed ◽  
Vapour Deposition ◽  
Volume Fraction ◽  
Chemical Vapour ◽  
Optical Transmittance ◽  
Undoped Sample ◽  
Maximum Value

Doping of nitrogen is a promising approach to improve the electrical conductivity of 3C-SiC and allow its application in various fields. N-doped, <110>-oriented 3C-SiC bulks with different doping concentrations were prepared via halide laser chemical vapour deposition (HLCVD) using tetrachlorosilane (SiCl4) and methane (CH4) as precursors, along with nitrogen (N2) as a dopant. We investigated the effect of the volume fraction of nitrogen (ϕN2) on the preferred orientation, microstructure, electrical conductivity (σ), deposition rate (Rdep), and optical transmittance. The preference of 3C-SiC for the <110> orientation increased with increasing ϕN2. The σ value of the N-doped 3C-SiC bulk substrates first increased and then decreased with increasing ϕN2, reaching a maximum value of 7.4 × 102 S/m at ϕN2 = 20%. Rdep showed its highest value (3000 μm/h) for the undoped sample and decreased with increasing ϕN2, reaching 1437 μm/h at ϕN2 = 30%. The transmittance of the N-doped 3C-SiC bulks decreased with ϕN2 and showed a declining trend at wavelengths longer than 1000 nm. Compared with the previously prepared <111>-oriented N-doped 3C-SiC, the high-speed preparation of <110>-oriented N-doped 3C-SiC bulks further broadens its application field.

Electrical Conductivity of VGCF/ Aluminum Composites Fabricated by Electro Spark Sintering

2007 ◽  
Vol 561-565 ◽  
pp. 729-732 ◽  
Author(s):  
Gen Sasaki ◽  
Fumiaki Kondo ◽  
Kazuhiro Matsugi ◽  
Osamu Yanagisawa
Keyword(s):  
Electrical Conductivity ◽  
Residual Stress ◽  
Electrical Resistivity ◽  
Thermal Expansion ◽  
Carbon Fiber ◽  
Ultrasonic Vibration ◽  
Volume Fraction ◽  
Pure Aluminum ◽  
Average Diameter ◽  
Aluminum Powders

Vapor grown carbon fiber (VGCF) was sleaved in acetone with ultrasonic vibration. Then pure aluminum powders with 3 μm in average diameter was poured into VGCF containing acetone and mixed with ultrasonic vibration. The composites were fabricated by electro spark sintering. The strength, rigidity, electrical conductivity and microstructure of the composites was investigated. VGCF was distributed uniformly and no pores was observed in composite. As increasing the volume fraction of VGCF in composites, the strength of composites increased gradually but the elongation decreased. The electrical resistivity of the composites increased as increasing VGCF content, constantly. The theoretical resistivity of composites without residual stress is lower than that of experimental results. It seems that is caused by the high dislocation density and strain introduced by big difference of thermal expansion between VGCF and pure aluminum.

Dynamics of Phase Transformation of Cu-Ni-Si-Zr-Cr Alloy during Aging Precipitation

2012 ◽  
Vol 490-495 ◽  
pp. 3109-3113
Author(s):  
Xiang Peng Xiao ◽  
Bai Qing Xiong ◽  
Qiang Song Wang ◽  
Guo Liang Xie ◽  
Li Jun Peng
Keyword(s):  
Electrical Conductivity ◽  
Phase Transformation ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Avrami Equation ◽  
Transformation Kinetics ◽  
Transformation Ratio ◽  
Aging Precipitation ◽  
Effects Of Aging ◽  
New Phase

The effects of aging temperature and aging time on properties of Cu-2.1Ni-0.5Si -0.2Zr-0.05Cr (wt.%) alloy were studied. The transformation ratio of new phase in Cu-2.1Ni-0.5Si-0.2Zr-0.05Cr alloy was calculated when aging at 400°C, 450°C and 500°C by measuring electrical conductivity, the relation between the electrical conductivity and the quantity of new phase. The Avrami-equation of phase transformation kinetics and the Avrami-equation of electrical conductivity during aging were established for Cu-2.1Ni-0.5Si-0.2Zr-0.05Cr alloy, on the basis of linear relationship between the electric conductivity and the volume fraction of precipitates. The calculated values of electrical conductivity well consistent with those of experiment can provide reference on the alloy of production process. The characteristics of precipitates in the alloy after solution treatment and cold rolling were established, and the results show the precipitate was δ-Ni2Si phase.

Microstructure and Properties of Cu-Cr Alloys Prepared by a Shortened Process and a Conventional Process

2011 ◽  
Vol 199-200 ◽  
pp. 1890-1895 ◽  
Author(s):  
Cheng Dong Xia ◽  
Ming Pu Wang ◽  
Gen Ying Xu ◽  
Wan Zhang ◽  
Yan Lin Jia ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Cold Rolling ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Conductivity Measurement ◽  
Electrical Conductivity Measurement ◽  
Copper Strip ◽  
Microstructure And Properties ◽  
Conventional Process ◽  
The Difference

The microstructure and properties of Cu-0.4wt%Cr alloys prepared by a shortened process and a conventional process were investigated by means of optical microscopy (OM), transmission electron microscopy (TEM), hardness testing and electrical conductivity measurement. After online hot rolling- quenching and cold rolling with 60% reduction and then aging at 450°C for 30min (process A), and solution treatment - cold rolling with 60% reduction - aging 450°C for 60min (process B), good properties combination of the alloys are obtained, and the hardness and electrical conductivity reach to 156HV, 86.4%IACS and 169HV, 81.1%IACS, respectively, and the shortened process (A) is suitable for commercial copper strip production. Plenty of fine and dispersed precipitates are responsible for the hardness and electrical conductivity improvement of the alloys. The difference of properties between process A and B is resulting form the difference of effective precipitates volume fraction under the various processes.

Design of High-Strength, High-Conductivity Alloys

MRS Bulletin ◽  
1996 ◽  
Vol 21 (6) ◽  
pp. 13-18 ◽  
Author(s):  
J. Miyake ◽  
G. Ghosh ◽  
M.E. Fine
Keyword(s):  
Electrical Conductivity ◽  
Computer Aided Design ◽  
Volume Fraction ◽  
High Strength ◽  
Pure Metal ◽  
Alloy Design ◽  
High Conductivity ◽  
Solid Solution Strengthening ◽  
Computer Aided ◽  
The Matrix

Computer-aided design of alloys is becoming increasingly useful, replacing the completely experimental approach. The computer-aided approach significantly reduces the cost of alloy design and more easily leads to optimum properties by reducing the amount of experimentation. Design of high-strength, high-conductivity alloys is a good example of the efficacy of using the computer to design experimental alloys.Alloys that have both high strength and high electrical conductivity are needed for many applications such as lead frames, connectors, conducting springs, and sliding contacts. Figure 1 shows the strength and conductivity of some commercially available copper-based alloys. Since dissolved solutes in an otherwise pure metal rapidly reduce the electrical conductivity (as well as the thermal conductivity), solid solution strengthening is not suitable for designing this class of alloys. Such alloys must be designed on the basis of precipitation or dispersion hardening. The theory of the yield stress of alloys with precipitates or dispersed phases has been well-formulated and may be used for alloy design. The solubility of the hardening phase in the matrix must be very small. Otherwise the conductivity will be degraded too much. Nordheim's rule relates conductivity to dissolved solute in alloys and is also available for alloy design. Decreasing the dissolved solute increases the conductivity and strength due to an increase in the volume fraction of the precipitate.

Improving the Electrical Conductivity of Composites Comprised of Short Conducting Fibers in a Nonconducting Matrix: The Addition of a Nonconducting Particulate Filler

1995 ◽  
Vol 390 ◽  
Author(s):  
Pu-Woei Chen ◽  
D. D. L. Chung
Keyword(s):  
Electrical Conductivity ◽  
Percolation Threshold ◽  
Silica Fume ◽  
Carbon Fibers ◽  
Volume Fraction ◽  
Filler Volume Fraction ◽  
Conducting Filler ◽  
Particulate Filler

ABSTRACTThe addition of a second discontinuous filler (silica fume) that is essentially nonconducting to a composite with a comparably non-conducting matrix (cement) and a conducting discontinuous filler (carbon fibers) was found to increase the electrical conductivity of the composite when the conducting filler volume fraction was less than 3.2%. The maximum conducting filler volume fraction for the second filler to be effective was only 0.5% when the second filler was sand, which was much coarser than silica fume. The improved conductivity due to the presence of the second filler is due to the improved dispersion of the conducting filler. The silica fume addition did not affect the percolation threshold, but the sand addition increased the threshold.

Influence of Co on Strength of Cu-Ni-Co-Si Alloy

2014 ◽  
Vol 783-786 ◽  
pp. 2468-2473 ◽  
Author(s):  
Atsushi Ozawa ◽  
Chihiro Watanabe ◽  
Ryoichi Monzen
Keyword(s):  
Electrical Conductivity ◽  
Dislocation Density ◽  
Cold Rolling ◽  
Volume Fraction ◽  
Crystal System ◽  
The Difference ◽  
Co Alloys

The effects of Co on the strength of Cu-Ni-Co-Si alloys have been investigated using Cu-2.0wt%Ni-0.5wt%Si (0%Co), Cu-1.4wt%Ni-0.6wt%Co-0.5wt%Si (0.6%Co) and Cu-1.0wt% Ni-1.0wt%Co-0.5wt%Si (1.0%Co) alloys produced by combining cold rolling to a 25% reduction with aging. Aging the 0.6%Co and 1.0%Co alloys at 525 and 425°C produces orthorhombic (Ni, Co)2Si precipitates that have the same crystal system as Ni2Si precipitates formed in the 0%Co alloy. The larger the amount of Co in the three alloys is, the higher the strength and electrical conductivity of the alloys initially aged at 525°C, rolled to a 25% reduction and re-aged at 425°C become. The increase in strength with increasing Co content is caused by both of the decrease in inter-precipitate spacing and increase in dislocation density. The increase in strength by re-aging at 425°C becomes more pronounced as the Co content increases. This arises because the larger the amount of Co is, the larger the difference between the equilibrium solubilities at 525 and 425°C becomes, the more the volume fraction of precipitates is increased by re-aging at 425°C.

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