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Gang Qian - One of the best experts on this subject based on the ideXlab platform.
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Effect of electrical current density, apparent Contact pressure, and sliding velocity on the electrical sliding wear behavior of Cu–Ti3AlC2 composites
Wear, 2020Co-Authors: Hao Zhao, Gang Qian, Yi Feng, Zijue Zhou, Jingcheng Zhang, Xiaochen Huang, Xuebin ZhangAbstract:Abstract The purpose of this research was to investigate the potential use of Cu–Ti3AlC2 composites sliding against a Cu–5%Ag alloy as a viable electrical Contact couple. Sliding friction and wear tests were conducted in the presence of an electric current using a custom-designed block-on-ring wear testing apparatus. The electrical current density was 0–15 A/cm2 along with an apparent Contact pressure of 1.25–7.5 N/cm2 and sliding velocities ranging from 2.5 to 15 m/s. The results indicate that friction coefficient, wear rate, and Contact Voltage drop measured for the sliding couple increases with an increase in the electrical current density. As the apparent Contact pressure increases, the Contact Voltage drop of Cu–Ti3AlC2 composites increases gradually, while friction coefficient and wear rate first decrease and then increase. With an increase in the sliding velocity, the friction coefficient of the sliding pair decreases and the Contact Voltage drop increases gradually, while wear rate decreases first, then increases. Adhesive wear and arc erosion wear proposed as the main wear modes. A lubricating film was observed to form on the wear surfaces under each test condition, and that film apparently improves the tribological properties of the sliding couples.
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Effect of current polarity on electrical sliding wear behavior of Cu-WS 2 -graphite-WS 2 nanotube composites in air and vacuum conditions
Science China Technological Sciences, 2013Co-Authors: Gang Qian, Yi Feng, Fanyan Chen, Liu Wenhong, Xuebin Zhang, Yan-fang LiuAbstract:In this paper Cu-WS2-graphite-WS2 nanotube composites were fabricated by powder metallurgy hot pressing method. The effect of current polarity on the wear rates and Contact Voltage drops of the composites were investigated using a brush-on-slip ring tribometer rubbing against Cu-5 wt.% Ag alloy ring in air and vacuum, respectively. The worn surfaces of the composites were analyzed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Surface profile curves of the worn tracks were measured using the surface profiler. The results demonstrated that the current polarity has a significant effect on the wear rates and Contact Voltage drops of the composites in both air and vacuum conditions. Positive brush possesses a higher wear rate compared with the negative brush in the air atmosphere since the electrical field direction activates oxidation at the positive brush surface while inhibits oxidation at the negative brush surface. Except for the regular wear losses, the combined effect of molten metal bridge erosion and arc erosion cause the positive brush to lose extra material and the negative brush to gain extra material, so the positive brush shows a higher wear rate in the vacuum condition. The Contact Voltage drop of the positive brush is lower than that of the negative brush in the air atmosphere, but contrarily, the positive brush shows a higher Contact Voltage drop in the vacuum condition.
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electrical sliding friction and wear properties of cu mos2 graphite ws2 nanotubes composites in air and vacuum conditions
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013Co-Authors: Shiyin Huang, Yi Feng, Kewang Ding, Gang QianAbstract:Abstract Cu–MoS 2 –graphite–WS 2 nanotubes composites were fabricated by the P/M hot pressing method. The tribological properties and Contact Voltage drops of the composites were investigated using a block-on-ring friction and wear tester in air and vacuum respectively, rubbing against Cu-5 wt% Ag alloy ring with different electric current. Tribo-films formed on the worn surfaces were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Results illustrated that the friction coefficients and wear rates in air were lower than those in vacuum due to the synergistic effect of lubrication from the mixture of MoS 2 and graphite in air and the limited lubrication properties of graphite in vacuum. The friction coefficients and wear rates increased gradually with the increasing current density because of the additional Joule heat resulting from the release of current. The Contact Voltage drops were low in the initial stage, and then increased to a stable value owing to the gradual formation of tribo-films on the sliding surface which changed the nature asperities from metal-metal to metal-film-metal type on the Contact interfaces of composites and rings.
Erwann Carvou - One of the best experts on this subject based on the ideXlab platform.
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Effect of Vibration Frequency on Mechanical Behavior of Automotive Sensor
Proceedings of the International Conference of Mechatronics and Cyber-MixMechatronics – 2018, 2018Co-Authors: Rochdi El Abdi, Julien Labbé, Florence Le Strat, Erwann CarvouAbstract:Due to repetitive micro-displacements, the fretting phenomenon was defined as an electrical and mechanical degradation of the electrical Contact interface in automotive sensors. Commonly, the electrical degradation was quantified by the increase of Contact resistance deduced from the Contact Voltage. This work aims to address the analysis of relative displacements according to three space directions between sensor components in Contact for different vibration frequencies for a Top Dead Center sensor. Particular attention was paid to measurements of displacements near crimping zones.
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Effect of vibration frequency on mechanical behavior of automotive sensor
International Journal of Mechatronics and Applied Mechanics, 2018Co-Authors: Rochdi El Abdi, Julien Labbé, Florence Le Strat, Erwann CarvouAbstract:Due to repetitive micro-displacements, the fretting phenomenon was defined as an electrical and mechanical degradation of the electrical Contact interface in automotive sensors. Commonly, the electrical degradation was quantified by the increase of Contact resistance deduced from the Contact Voltage. This work aims to address the analysis of relative displacements according to three space directions between sensor components in Contact for different vibration frequencies for a Top Dead Center sensor. Particular attention was paid to measurements of displacements near crimping zones. © 2018, Cefin Publishing House. All rights reserved.
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Fluctuation of Contact Voltage During Fretting Phases
Proceedings of the International Conference of Mechatronics and Cyber-MixMechatronics - 2017, 2017Co-Authors: Rochdi El Abdi, N. Benjemaa, Erwann Carvou, Sofiane El Mossouess, Laurent DoubletAbstract:Due to repetitive micro-displacements, the fretting phenomenon was defined as an electrical and mechanical degradation of the electrical Contact interface in telecommunications and more recently in power automotive connectors. Commonly, the electrical degradation was quantified by the increase of Contact resistance deduced from the Contact Voltage. This work aims to address the analysis of the change of Contact temperature and the Contact Voltage during the three successive fretting phases at low and high level Contacts. U-shape samples of cooper with a tin protective coating were used and fixed on a vibration system.
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Effect of Coating Contact Materials (Sn, Ag, Au) on Power Contact Voltage Fluctuation During Fretting Corrosion
2016Co-Authors: Sofiane El Mossouess, N. Benjemaa, Julien Labbé, Laurent Doublet, Rochdi El Abdi, Erwann Carvou, T. RodariAbstract:Yrtttvaf, corrosion phenomenon is known as the main cause of Contact Voltage fluctuation in tin, Ag and Au coatcd materials Contact at low level. Until now, these investigations were done with low current (a few milliamps), an unrealistic value for some higher current automotive applications. Indeed, in these cases, the joule effect due to fretting Voltage increases, leading to heat the Contact zone with some consequences like increasing oxidation, or softening Sn coating. Furthermore, higher Voltage (up to 14V), induces large Voltage fluctuations and subsequent arcing occurrence are observed. In this work, we will determine the relationship between the coating nature and fretting Voltage characteristics, especially fluctuation and level evolution. For this aim an experimental study was done on sphere/plan Contacts made with cooper, coatcd with tin, silver and gold. These Contacts are submitted to vibration amplitudes up to 100 micrometers at frequencies of a few 50Hz, under a current of 10A and a Voltage of 16VDC. The average Contact fluctuations are measured during one cycle while fast fluctuations inside the cycles are measured by oscilloscope Indeed, the analysis of the Voltage fluctuations in term of level and time appearance is a very useful tool to analyze in-situ fretting behavior. Upon analysis of experimental data, it is found that noble coating (Ag, Au) show lower and delayed average Voltage fluctuations over the cycle. Moreover, fast fluctuations can reach arc Voltage with variable occurrences and time.
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Statistical analysis of Voltage from constriction to micro-arc values during aging by fretting
2015 IEEE 61st Holm Conference on Electrical Contacts (Holm), 2015Co-Authors: El S. Mossouess, N. Benjemaa, Yee Kin E. Choi, El R. Abdi, Laurent Doublet, T. Rodari, Erwann CarvouAbstract:In a previous work we observe that the vibration of Contact interfaces is the main cause of Contact Voltage fluctuations due to the so called fretting corrosion phenomenon. In fact the process of generated particles by mechanical wear produce the increase of Contact Voltage frequently assimilated as high Contact resistance. The main objective of this work is to examine conjointly Contact Voltage and the occurrence of arcs during the well-known three successive fretting phases. The arc Voltage is measured during fretting with set oscilloscopes which plot the arc Voltage histograms in real time. So, a histogram is built and arc duration is determined and the position on the track of fretting. We applied a Voltage of 16V and a current of 3A. Samples extracted from commercial Contact are used and fixed on vibration system (frequency 20Hz and relative displacement of 0.8 mm). The main results show that the arcs are observed during the first and final phase of fretting. We assume that after the initiation period of fretting, the wear is increased and induce the increase of the Contact Voltage and it reaches few hundred millivolts (melting and fritting Voltage) and induce micro-arcs. In the second phase, it seems that number of arcs decreases. Finally in ultimate stage of degradation, intermittent arcing Voltage is detected close 12V due to bounce on degraded surface filed wear debris.
Kongjun Zhou - One of the best experts on this subject based on the ideXlab platform.
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Study and experiment on non-Contact Voltage sensor suitable for three-phase transmission line
Sensors (Switzerland), 2016Co-Authors: Qiang Zhou, Songnong Li, Dongping Xiao, W He, Kongjun ZhouAbstract:A Voltage transformer, as Voltage signal detection equipment, plays an important role in a power system. Presently, more and more electric power systems are adopting potential transformer and capacitance Voltage transformers. Transformers are often large in volume and heavyweight, their insulation design is difficult, and an iron core or multi-grade capacitance Voltage division structure is generally adopted. As a result, the detection accuracy of transformer is reduced, a huge phase difference exists between detection signal and Voltage signal to be measured, and the detection signal cannot accurately and timely reflect the change of conductor Voltage signal to be measured. By aiming at the current problems of electric transformation, based on electrostatic induction principle, this paper designed a non-Contact Voltage sensor and gained detection signal of the sensor through electrostatic coupling for the electric field generated by electric charges of the conductor to be measured. The insulation structure design of the sensor is simple and its volume is small; phase difference of sensor measurement is effectively reduced through optimization design of the electrode; and Voltage division ratio and measurement accuracy are increased. The Voltage sensor was tested on the experimental platform of simulating three-phase transmission line. According to the result, the designed non-Contact Voltage sensor can realize accurate and real-time measurement for the conductor Voltage. It can be applied to online monitoring for the Voltage of three-phase transmission line or three-phase distribution network line, which is in accordance with the development direction of the smart grid.
Qiang Zhou - One of the best experts on this subject based on the ideXlab platform.
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Research on Non - Contact Voltage Measurement Technology Based on Near Field Detection
2019 IEEE Sustainable Power and Energy Conference (iSPEC), 2019Co-Authors: Peng Wenxin, Qiang Zhou, Xingzhe HouAbstract:The construction requirements of the global energy internet greatly promote the information-based and intelligent development of electric power equipment. As the important component of electric power equipment, Voltage transformer adopts the double-side detection method. As a result, the transformer is large in volume and weight, and inaccurate in detection, etc. With regard to the existing problems of the current Voltage transformer, the non-Contact Voltage sensor is proposed on the basis of the near field detection method in this paper to achieve the Voltage detection in power transmission line and other electric devices. New method and means are provided for the Voltage detection of electric power system, contributing to promoting the information-based intelligent development level of electric power equipment in the global energy internet construction.
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Study and experiment on non-Contact Voltage sensor suitable for three-phase transmission line
Sensors (Switzerland), 2016Co-Authors: Qiang Zhou, Songnong Li, Dongping Xiao, W He, Kongjun ZhouAbstract:A Voltage transformer, as Voltage signal detection equipment, plays an important role in a power system. Presently, more and more electric power systems are adopting potential transformer and capacitance Voltage transformers. Transformers are often large in volume and heavyweight, their insulation design is difficult, and an iron core or multi-grade capacitance Voltage division structure is generally adopted. As a result, the detection accuracy of transformer is reduced, a huge phase difference exists between detection signal and Voltage signal to be measured, and the detection signal cannot accurately and timely reflect the change of conductor Voltage signal to be measured. By aiming at the current problems of electric transformation, based on electrostatic induction principle, this paper designed a non-Contact Voltage sensor and gained detection signal of the sensor through electrostatic coupling for the electric field generated by electric charges of the conductor to be measured. The insulation structure design of the sensor is simple and its volume is small; phase difference of sensor measurement is effectively reduced through optimization design of the electrode; and Voltage division ratio and measurement accuracy are increased. The Voltage sensor was tested on the experimental platform of simulating three-phase transmission line. According to the result, the designed non-Contact Voltage sensor can realize accurate and real-time measurement for the conductor Voltage. It can be applied to online monitoring for the Voltage of three-phase transmission line or three-phase distribution network line, which is in accordance with the development direction of the smart grid.
Yi Feng - One of the best experts on this subject based on the ideXlab platform.
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Effect of electrical current density, apparent Contact pressure, and sliding velocity on the electrical sliding wear behavior of Cu–Ti3AlC2 composites
Wear, 2020Co-Authors: Hao Zhao, Gang Qian, Yi Feng, Zijue Zhou, Jingcheng Zhang, Xiaochen Huang, Xuebin ZhangAbstract:Abstract The purpose of this research was to investigate the potential use of Cu–Ti3AlC2 composites sliding against a Cu–5%Ag alloy as a viable electrical Contact couple. Sliding friction and wear tests were conducted in the presence of an electric current using a custom-designed block-on-ring wear testing apparatus. The electrical current density was 0–15 A/cm2 along with an apparent Contact pressure of 1.25–7.5 N/cm2 and sliding velocities ranging from 2.5 to 15 m/s. The results indicate that friction coefficient, wear rate, and Contact Voltage drop measured for the sliding couple increases with an increase in the electrical current density. As the apparent Contact pressure increases, the Contact Voltage drop of Cu–Ti3AlC2 composites increases gradually, while friction coefficient and wear rate first decrease and then increase. With an increase in the sliding velocity, the friction coefficient of the sliding pair decreases and the Contact Voltage drop increases gradually, while wear rate decreases first, then increases. Adhesive wear and arc erosion wear proposed as the main wear modes. A lubricating film was observed to form on the wear surfaces under each test condition, and that film apparently improves the tribological properties of the sliding couples.
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Effect of current polarity on electrical sliding wear behavior of Cu-WS 2 -graphite-WS 2 nanotube composites in air and vacuum conditions
Science China Technological Sciences, 2013Co-Authors: Gang Qian, Yi Feng, Fanyan Chen, Liu Wenhong, Xuebin Zhang, Yan-fang LiuAbstract:In this paper Cu-WS2-graphite-WS2 nanotube composites were fabricated by powder metallurgy hot pressing method. The effect of current polarity on the wear rates and Contact Voltage drops of the composites were investigated using a brush-on-slip ring tribometer rubbing against Cu-5 wt.% Ag alloy ring in air and vacuum, respectively. The worn surfaces of the composites were analyzed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Surface profile curves of the worn tracks were measured using the surface profiler. The results demonstrated that the current polarity has a significant effect on the wear rates and Contact Voltage drops of the composites in both air and vacuum conditions. Positive brush possesses a higher wear rate compared with the negative brush in the air atmosphere since the electrical field direction activates oxidation at the positive brush surface while inhibits oxidation at the negative brush surface. Except for the regular wear losses, the combined effect of molten metal bridge erosion and arc erosion cause the positive brush to lose extra material and the negative brush to gain extra material, so the positive brush shows a higher wear rate in the vacuum condition. The Contact Voltage drop of the positive brush is lower than that of the negative brush in the air atmosphere, but contrarily, the positive brush shows a higher Contact Voltage drop in the vacuum condition.
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electrical sliding friction and wear properties of cu mos2 graphite ws2 nanotubes composites in air and vacuum conditions
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013Co-Authors: Shiyin Huang, Yi Feng, Kewang Ding, Gang QianAbstract:Abstract Cu–MoS 2 –graphite–WS 2 nanotubes composites were fabricated by the P/M hot pressing method. The tribological properties and Contact Voltage drops of the composites were investigated using a block-on-ring friction and wear tester in air and vacuum respectively, rubbing against Cu-5 wt% Ag alloy ring with different electric current. Tribo-films formed on the worn surfaces were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Results illustrated that the friction coefficients and wear rates in air were lower than those in vacuum due to the synergistic effect of lubrication from the mixture of MoS 2 and graphite in air and the limited lubrication properties of graphite in vacuum. The friction coefficients and wear rates increased gradually with the increasing current density because of the additional Joule heat resulting from the release of current. The Contact Voltage drops were low in the initial stage, and then increased to a stable value owing to the gradual formation of tribo-films on the sliding surface which changed the nature asperities from metal-metal to metal-film-metal type on the Contact interfaces of composites and rings.