Papers by Keyword: Electrical Conductivity

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Authors: Kok Chong Yong, Ahmad Kifli Che Aziz
Abstract: Electrostatic charges are potentially generated on a commercial vehicle through several ways, such as friction of its rubber tyres while rolling on the road and also from the rotating of its mechanical components (e.g. bearings shaft). If these accumulated electrostatic charges are not dissipated from the vehicle, interferences of electronic components within the vehicle may occur. Highly accumulated electrostatic charges may also lead to safety hazards (e.g. fires and explosions) for vehicles that transporting highly flammable materials or during the vehicles refueling process.
Authors: Shi Yong Luo, Juan Chen, Wen Cai Xu, Li Xia Huo, Jun Yan Zhao
Abstract: A lead free graphite conducting pastes were prepared by using graphite powder, lead free low-melting glass and terpineol ethyl cellulose solution. By analyzing the sheet resistance, Vickers hardness as well as the adhesion strength of the sintered film prepared by the pastes formulated with different composition, the composition of the paste with preferable properties was evaluated as in mass percent: organic vehicle 60, graphite powder 15~20, and low melting glass 20~25. The films, prepared by the pastes using the lead free glass with a glass transition temperature of 476°C, were perfectly flat and compact after fired at a peak temperature within the range from 520°C to 580°C. The sheet resistance of the fired film with glass content of 25wt% was 135Ω/mm2 when the thickness of the film was 25±3μm, while the Vickers hardness and the binder force between the sintered film and the substrate were favorable. In addition, the rheological behaviors of the typical paste were characterized by using an ARES (RFS-III) rheometer. It is found that a weak flocculated network structure is formed in the paste for the high solid filler.
Authors: Telmo G. Santos, Gonçalo Sorger, Pedro Vilaça, R.M. Miranda
Abstract: Recent studies showed that electrical conductivity is a valuable technique to identify the different zones of solid-state welded joints with a good correlation with the microstructure and hardness. This is a relevant result since this technique is expedite and, in some cases, non destructive. The concept was applied to other welding processes as the ones involving fusion and to a wide range of materials. For this, a comprehensive study was performed using friction stir welding, tungsten inert gas (TIG) and gas metal arc (MAG) welding processes in either bead on plate or butt joints in: carbon steel, magnesium and titanium. Eddy current non-destructive testing (NDT) was used to measure the electrical conductivity at different depths in transverse sections of the processed materials. The obtained profiles were compared to the hardness profiles in the same sections. As a result, a good correlation was observed in most materials welded by solid state and by fusion processes. The variation of the electrical conductivity closely follows the one detected in the hardness. Another interesting conclusion is that, even for fusion welding of carbon steels, the technique has potential to complement the hardness measurements and microstructural observations, allowing to identify the distinct zones of welds in materials commonly used in industry.
Authors: E. Ayas, Alpagut Kara, Ferhat Kara
Abstract: An effective approach for preparing electrically conductive SiAlON-TiN composites was developed. Granules of a designed composition of α- SiAlON was obtained by spray drying and coated with varying amounts of TiO2 powder homogenously by mechanical mixing. Fully dense composites were obtained by spark plasma sintering (SPS) under a pressure of 50 MPa at 1650°C for 5min. According to the SEM analysis, unique microstructures containing continuously segregated in-situ formed TiN phase in 3-D were achieved. Additionally, XRD studies revealed that all TiO2 was successfully converted to TiN. The resistivity of the α-β SiAlON (1x1011 .m) was drastically reduced with the addition of only 5 vol. % TiO2 (2x10-4 .m).
Authors: Hyung Kwon Moon, Seung Boo Jung, Je Sik Shin
Abstract: In this paper, it was aimed to develop a new interconnect material having high electrical conductivity and strength simultaneously. The Cu composite sheet, possessing mesh type Ag conduction paths on the surface of a high strength Cu alloy sheet, was manufactured by damascene electroplating. The peel strength of Cu composite sheet prepared by damascene electroplating increased by above 50 times compared to Cu composite sheet by conventional electroplating. Al wire wedge bonding was able to be successfully conducted without extra metal thin film coating.
Authors: O.M. Shabanov, L.A. Kazieva, Sagim I. Suleymanov
Abstract: The electrical conductivity of molten sodium and potassium chloroaluminumates increase with increasing electrical field strength and reach the limiting values. The limiting high-voltage conductivities of the melts surpass their usual values up to 200% in NaAlCl4 and 700% in KAlCl4. These results have been obtained on the base of analysis of the microsecond high-voltage discharges in the melts (the Wien effect). After the high-voltage pulses discharges having been completed in the melts, their conductivity has been found to rise up to 50% (the “memory effect”). The relaxation time of a non-equilibrium state reaches 5 minutes and more.
Authors: Xiang Peng Xiao, Bai Qing Xiong, Qiang Song Wang, Guo Liang Xie, Li Jun Peng
Abstract: The microstructural features and heat treatment response of Cu-2.1Ni-0.5Si-0.2Zr-0.05Cr (wt.%) alloy have been investigated. The alloy was aged at 400°C、450°C and 500°C after a cold deformation of 70% reduction. The variation in hardness and electrical conductivity of the alloy was measured as a function of aging time. The results indicated the highest peak hardness value of approximately 205HV for the alloy aged at 400°C for 4h after the solution treatment and cold deformation. The alloy has two main phases, one is Ni2Si phase, and the other is Cr2Zr phase. The strengthening mechanisms of the alloy include spinodal decomposition strengthening, ordering strengthening and precipitation strengthening.
Authors: Hoon Cho, Byoung Soo Lee, Bok Hyun Kang, Ki Young Kim
Abstract: To develop Cu alloy with tensile strength of 800 MPa and electrical conductivity of 80 %IACS (International Annealed Copper Standard), the variation of mechanical strength and electrical conductivity in Cu-Ag alloy during fabrication processes including casting, solid solution and ageing treatment were investigated. Solid solution hardening leads to a large drop in electrical conductivity of Cu-Ag alloys due to super-saturation of Ag solute in Cu matrix. Ageing hardening gives rise to enhance both of the mechanical strength and the electrical conductivity. Therefore, it can be mentioned that the electrical conductivity of Cu-Ag alloys was affected dominantly by Ag solute in Cu matrix.
Authors: Hirotaka Matsunaga, Z. Horita, Kazutaka Imamura, Takanobu Kiss, Xavier Sauvage
Abstract: An age-hardenable Cu-2.9%Ni-0.6%Si alloy was subjected to high-pressure torsion. Aging behavior was investigated in terms of hardness, electrical conductivity and microstructural features. Transmission electron microscopy showed that the grain size is refined to ~150 nm and the Vickers microhardness was significantly increased through the HPT process. Aging treatment of the HPT-processed alloy led to a further increase in the hardness. Electrical conductivity is also improved with the aging treatment. It was confirmed that the simultaneous strengthening by grain refinement and fine precipitation is achieved while maintaining high electrical conductivity. Three dimensional atom probe analysis revealed that fine precipitates with sizes of ~20 nm or smaller were formed in the Cu matrix and some particles consist of Ni and Si with no appreciable amount of Cu.
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