scholarly journals Tribological Wear Behaviour of Electrical Contacts Made from AgNi10 Composite

2017 ◽  
Vol 62 (4) ◽  
pp. 2007-2013 ◽  
Author(s):  
M.W. Richert ◽  
G. Boczkal ◽  
A. Hotloś ◽  
P. Pałka ◽  
M. Karpiński
Keyword(s):  
Electrical Properties ◽  
Electrical Resistance ◽  
Alternating Current ◽  
Electrical Contacts ◽  
Contact System ◽  
Wear Behaviour ◽  
Duty Cycles ◽  
High Degree

AbstractThe effect of tribological wear of contacts made from an AgNi10 alloy on microstructure and electrical properties was investigated. The contacts were tested in duty cycles loaded with alternating current of 10A intensity. With this value of the current, intensive arcing of contacts occurred. The contacts were tested in the range of 125 to 500 thousand cycles. The contacting surfaces were reported to suffer a high degree of wear, but electrical resistance of the contact system remained stable.

scholarly journals Effect of Applied Pressure on the Electrical Resistance of Carbon Nanotube Fibers

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2106
Author(s):  
Chris J. Barnett ◽  
James D. McGettrick ◽  
Varun Shenoy Gangoli ◽  
Ewa Kazimierska ◽  
Alvin Orbaek White ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electrical Resistance ◽  
Copper Wire ◽  
Applied Pressure ◽  
Radial Strain ◽  
Electrical Current ◽  
Electrical Contacts ◽  
Electrical Performance ◽  
Macro Scale ◽  
Carbon Nanotube Fibers

Carbon nanotubes (CNTs) can be spun into fibers as potential lightweight replacements for copper in electrical current transmission since lightweight CNT fibers weigh <1/6th that of an equivalently dimensioned copper wire. Experimentally, it has been shown that the electrical resistance of CNT fibers increases with longitudinal strain; however, although fibers may be under radial strain when they are compressed during crimping at contacts for use in electrical current transport, there has been no study of this relationship. Herein, we apply radial stress at the contact to a CNT fiber on both the nano- and macro-scale and measure the changes in fiber and contact resistance. We observed an increase in resistance with increasing pressure on the nanoscale as well as initially on the macro scale, which we attribute to the decreasing of axial CNT…CNT contacts. On the macro scale, the resistance then decreases with increased pressure, which we attribute to improved radial contact due to the closing of voids within the fiber bundle. X-ray photoelectron spectroscopy (XPS) and UV photoelectron spectroscopy (UPS) show that applied pressure on the fiber can damage the π–π bonding, which could also contribute to the increased resistance. As such, care must be taken when applying radial strain on CNT fibers in applications, including crimping for electrical contacts, lest they operate in an unfavorable regime with worse electrical performance.

scholarly journals Вплив параметрів адитивного формування на електричні властивості графітонаповненого композиту на основі полілактиду

2021 ◽  
Vol 150 (5) ◽  
pp. 93-102
Author(s):  
Н. В. Сова ◽  
О. О. Слепцов ◽  
Т. Р. Федорів ◽  
А. О. Мартиненко ◽  
М. Р. Кудлай ◽  
...  
Keyword(s):  
Electrical Properties ◽  
3D Printing ◽  
Electrical Resistance ◽  
Specific Resistance ◽  
Polymer Melt ◽  
Electrical Characteristics ◽  
Additive Production ◽  
Filled Composite ◽  
Printing Parameters ◽  
Bulk Electrical Resistance

Purpose. Investigate the effect of additive formation parameters on the properties of an antistatic composition based on polylactide (PLA). Methodology. Surface and bulk electrical resistance were determined by ASTM D257. Findings. The influence of additive formation parameters on the electrical properties of graphite-filled composite based on polylactide has been studied. It was found that the value of resistivity significantly depends on the printing conditions, namely the temperature, speed, thickness of the layer. Increasing the printing temperature helps to reduce the resistivity of the sample. Reducing the thickness of the polymer layer also reduces the resistivity at a print speed within 3000 mm / min It was found that the specific electrical characteristics are significantly different in the plane of the sample in contact with the printing platform. Concentric method of laying layers of polymer melt is less effective in terms of resistivity than mutually perpendicular. It was found that the electrical resistivity of samples made of material for 3D printing, which was previously subjected to drying below the resistance of the sample made of undried material. The programmed change of 3D printing parameters allows to control the specific resistance of graphite-filled composite based on polylactide in the range of three orders and to obtain products with properties from antistatic to statically dissipative materials. Additive production allows to obtain products of the desired configuration with adjustable electrical properties. Originality. The peculiarities of the change of antistatic properties of the polymer composite depending on the conditions of additive formation of experimental samples are investigated. Depending on the applied parameters of additive molding, it is possible to obtain products with properties from antistatic to statically dissipative materials. Practical value. Technological modes of additive molding of composite products based on polylactide and graphite have been developed. Energy consumption for additive formation of products of different mass is estimated.

scholarly journals The influence of multifunctional microalloyed ceramics microstructure on its capacity properties

2018 ◽  
Vol 15 (2) ◽  
pp. 187-199
Author(s):  
Jelena Purenovic ◽  
Nedeljko Ducic ◽  
Branko Matovic ◽  
Milovan Purenovic
Keyword(s):  
Crystal Structure ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Electrical Resistance ◽  
Ceramic Materials ◽  
Porous Ceramics ◽  
Electrophysical Properties ◽  
Microstructural Properties ◽  
Structure Morphology ◽  
Composition Structure

Modified porous alumo-silicate ceramics, alloyed with magnesium and microalloyed with aluminum, belongs to modern multifunctional ceramic materials. Microalloying has led to important changes in dielectric and electrical properties of ceramics, such as dielectric constant and electrical resistance. These changes are conditioned by the microstructural properties of modified porous ceramics. The obtained results have shown the unity of the influence of composition, structure, morphology and application of microalloyed multifunctional alumosilicate ceramics on electrophysical properties. Microstructural investigations have shown that this type of ceramics has an amorphous-crystal structure, which causes important changes in its electrical properties and affects its activity. Therefore the ceramics can be considered as an active dielectric. A correlation between microstructural properties and structurally sensitive, i.e. electrophysical properties of microalloyed multifunctional alumo-silicate ceramics, was confirmed.

scholarly journals Investigation of the effect of carbon nanotubes on electrical properties of woven fiberglass/epoxy composite laminate

2019 ◽  
Vol 196 ◽  
pp. 00019
Author(s):  
Elivazeta Kalugina
Keyword(s):  
Electron Microscopy ◽  
Electrical Properties ◽  
Fatigue Test ◽  
Electrical Resistance ◽  
Composite Laminate ◽  
Epoxy Composite ◽  
Microstructural Analysis ◽  
Lcr Meter ◽  
Cracking Zone ◽  
Scanning Electron

The effect of epoxy modified by 0.05 wt. % of CNTs on electrical properties of woven fiberglass/epoxy composite laminate was examined. The electrical resistance was measured using 4-point probe method and LCR-meter during cyclic tensile and fatigue test. Microstructural analysis using field emission scanning electron microscopy (FESEM) was carried out. Based on the experimental data, the increase in load is accompanied by growth in electrical resistance. The change in resistance after 20 cycles was up to 3 %. During fatigue test, the change in resistance was considerable and made up to 25 % in cracking zone of the sample and over 110 % at the failure mode.

scholarly journals Development of a Novel Resistance Heating System for Microforming Using Surface-Modified Dies and Evaluation of Its Heating Property

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 440
Author(s):  
Ming Yang ◽  
Tetsuhide Shimizu
Keyword(s):  
Electrical Properties ◽  
Compression Test ◽  
Stress Reduction ◽  
Electrical Resistance ◽  
Heating System ◽  
Resistance Heating ◽  
Heating Efficiency ◽  
Coated Tools ◽  
Modified Surfaces ◽  
Surface Modified

For this study, a novel resistance heating system for microforming was developed using surfaces of forming dies as heating resources. The electrical resistance of the die surfaces was designed and the hard-coating material AlCrSiN was selected to coat the die surfaces for heating. To clarify the effects of the thickness and modified surfaces on heating efficiency, the temperature and stress reduction were evaluated in a micro-compression test using dies coated with 0.5 and 1 μm AlCrSiN films. Furthermore, the formability was also demonstrated using 1 μm thick AlCrSiN-coated tools in a microforging test. By applying surface-modified dies to the forming processes, we found that not only was the heating efficiency improved, but also the dependence of heating on the product’s shape and the material’s electrical properties was reduced.

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