Contact welding strength measurement for metal electrode materials conducting inrush electrical current

2020 ◽  
Vol 91 (10) ◽  
pp. 104706
Author(s):  
Wanbin Ren ◽  
Xu Zhang

1. Recent experiments by Reimann and Treloar among others have thrown further light on the way in which the electrical current supplying the filament emission passes through the coating of barium- or strontium-oxide, used to render the filament a low-temperature emitter. They have studied in particular the variation of the current flowing with applied potential and with temperature. Though these phenomena have been elaborately discussed already by these authors and also by Reimann and Murgoci, by Becker and by Lowry, it seems to us possible that something new can be said in the light of the more detailed theory of semi-conductors and rectifying contacts now available. It is possible that in return for the study of conductivity some light may be thrown on the most perplexing feature of thermionic emission from oxide-coated cathodes—its failure to saturate properly for moderate voltages. The recent experimental work of Reimann and Treloar need only be shortly summarised here. The conductivity measurements were made by measuring the current between two oxide-coated nickel filaments twisted tightly together and recoated after twisting. [The two twisted wires were used jointly as a single cathode for thermionic measurements.] The conductivity as measured is therefore derived from the current flowing from metal electrode to metal electrode for given potential difference between the electrodes, deeply immersed in the oxide and separated by a thickness of oxide of the order of 0⋅02 mm.


2016 ◽  
Vol 1136 ◽  
pp. 418-422 ◽  
Author(s):  
Manabu Iwai ◽  
Hideaki Hashimoto ◽  
Kiyoshi Suzuki

For the purpose of improving the electric discharge machinability of PCD, the authors have proposed a method using an electrode made of a specific transition metal which is easy to react with diamond. As a result, Ti, Nb, Ta, Mo, and W among various reactive metals brought very high efficiency, higher than 3 times of existing electrode materials (Cu, CuW) in the EDM of PCD. It was thought that the higher removal efficiency was due to the material properties such as mixing enthalpy between transition metal atom and carbon atom and a crystal structure of body centered cubic (bcc) lattice.


2020 ◽  
Vol 9 (1) ◽  
pp. 1610-1624
Author(s):  
Xinxia Yang ◽  
Yi Peng ◽  
Jia Hou ◽  
Yifan Liu ◽  
Xian Jian

Abstract As the most common energy storage technology on the market, lithium-ion batteries are widely used in various industries and have a profound impact on our daily lives, with the characteristics of high voltage, high capacity, good safety performance, and long cycle life. Lithium metal was first used in the anode of lithium-ion batteries. However, the inherent growth of lithium dendrites and the instability of the SEI film limit the practical application of lithium metal materials. Despite this, lithium metal is still an ideal anode material to meet the growing demands for electronic equipment and electric vehicles due to its extremely high theoretical specific capacity, low density, and the lowest negative electrochemical potential. With the urgent need to develop new energy storage technologies, the research on lithium metal anodes has once again received extensive attention. In this review, the research progress in the modification of composite lithium metal electrode materials is summarized, including lithium/alloy composite electrode, lithium/carbon-based materials composite electrode and artificial SEI film. The possible directions for future development of lithium metal electrode are also prospected.


2020 ◽  
Vol 20 (10) ◽  
pp. 6489-6494
Author(s):  
Batkhuyag Khorolsuren ◽  
Shenmin Lu ◽  
Chao Sun ◽  
Fang Jin ◽  
Wenqin Mo ◽  
...  

To study the substitutability of noble metal electrodes in memristors, the effect of Pt/HfO2/Ti structure on the replacement of noble metal electrode Pt by different electrodes was studied. Compared with the unsubstituted devices, the HfO2-based RRAM devices with TiN and TiOxNy electrodes devices showed good resistive switching performance and resistive switching mechanism under oxygen ion migration. Five devices were prepared, and their resistive switching mechanism under oxygen ion migration was investigated. Moreover, besides the resistive switching phenomenon of these RRAM devices, it was found that significant rectifying characteristics were exhibited in a highresistance state (HRS). This phenomenon can be explained by regulation of the Schottky barrier of the interface between the top electrode and the resistive layer, which can be influenced by the migration of oxygen vacancies.


1999 ◽  
Vol 596 ◽  
Author(s):  
A. M. Clark ◽  
Jianhua Hao ◽  
Weidong Si ◽  
X. X. Xi

AbstractSrTiO3 (STO) thin films were grown by pulsed laser deposition on single crystal STO substrates with a SrRuO3 buffer layer, which also serves as a bottom electrode. Measurements of the low frequency dielectric properties were performed in a parallel plate capacitor configuration for a range of temperatures using different top electrode materials. The contribution to the interfacial potential from Schottky barriers was investigated. In comparison to STO single crystals, thin films have continued dielectric non-linearity above T ∼ 70 K. This complicates conventional Schottky barrier height measurements using C-V curves because both Schottky barriers and dielectric non-linearity result in a decrease in dielectric constant under applied electric fields. However, by using I-V data, difficulties related to field dependence of the dielectric constant may be removed. Barrier height measurements for both metal and oxide electrodes were performed for T > 70 K. Calculated barrier heights from a modified Schottky equation were very low for an oxide electrode, and an order of magnitude higher for a normal metal electrode.


2019 ◽  
Vol 947 ◽  
pp. 130-134
Author(s):  
Dhammasook Mingmuang ◽  
Sukangkana Talangkun ◽  
Supasit Paengson ◽  
Tosawat Seetawan

The objective of this article was to demonstrate the alternative method to produce the metal electrode on ceramic substrate. AA1100 aluminium alloy was thin-coated on alumina substrate by friction surfacing using a CNC milling machine. The properties of the coating layer were presented. After that, the coated ceramic substrate was connected to a thermoelectric material and used as thermoelectric electrode of the thermoelectric cell. Voltage, differential temperature and electrical current were measured. Power and efficiency of the thermoelectric cell were calculated. The maximum temperature at hot side of the thermoelectric cell was 171.48 °C. At this temperature, the voltage was 0.00027 mV and the power was 0.000655 W. Efficiency of the fabricated thermoelectric cell was 4.715 x 10-7.


2007 ◽  
Vol 124-126 ◽  
pp. 791-794
Author(s):  
Young Min Choi ◽  
Jong Ung Kim ◽  
Beyong Hwan Ryu ◽  
Hyun Ju Chang ◽  
Chung Heop Kwak ◽  
...  

In general, Electrostatic chuck (ESC) was used to fix and clamp the silicon wafer with electrostatic force in the semiconductor fabrication process. Recently, due to their excellent chemical and plasma stability and high thermal conductivity, sintered ceramics has been used as an insulator material in the configuration of ESC. However, metals of high melting point, such as Mo, W, still used for electrode materials. Because of the thermal mismatch between metal electrode and ceramic insulator, micro cracks were produced at the interface during sintering process of ceramic or its operation process with high temperature, which leads to reduce the life time of ESC. To improve the compatibility between metal and ceramic, mesh type metal electrode was used in ESC but this type of electrode results in inhomogeneous electrostatic force. Homogeneous clamping force is very important to determine the final quality of semiconductor. We have investigated a ceramic electrostatic chuck composed of conducting ceramic electrode of titanium nitride instead of metal electrode. Aluminum nitride was added to titanium nitride to control the thermal expansion coefficient. This composite electrode shows not only a good electrical conductivity but also an excellent compatibility to dielectric layer. Compatibility between the electrode and dielectric layer enable to design the electrode with continuous sheet type which leads to homogeneous electrostatic force. Electrostatic force of ceramic ESC with conducting ceramic electrode was about 1700gf/4inch wafer when the applied voltage was DC 3kV.


Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 110 ◽  
Author(s):  
Sait Elmas ◽  
Thomas Macdonald ◽  
William Skinner ◽  
Mats Andersson ◽  
Thomas Nann

Conjugated polymers with stabilizing coordination units for single-site catalytic centers are excellent candidates to minimize the use of expensive noble metal electrode materials. In this study, conjugated metallopolymer, POS[Cu], was synthesized and fully characterized by means of spectroscopical, electrochemical, and photophysical methods. The copper metallopolymer was found to be highly active for the electrocatalytic hydrogen generation (HER) in an aqueous solution at pH 7.4 and overpotentials at 300 mV vs. reversible hydrogen electrode (RHE). Compared to the platinum electrode, the obtained overpotential is only 100 mV higher. The photoelectrochemical tests revealed that the complexation of the conjugated polymer POS turned its intrinsically electron-accepting (p-type) properties into an electron-donor (n-type) with photocurrent responses ten times higher than the organic photoelectrode.


Author(s):  
И.М. Соцкая ◽  
А.С. Угловский

В системе SORPAS®метод конечных элементов используется для создания численных моделей, позволяющих моделировать процессы контактной сварки. Моделирование процессов сварки выполняется для определения (испытания) свариваемости новых материалов путём прогнозирования результатов, возникающих в ходе использования конкретных базовых материалов, электродных материалов и параметров процесса сварки. Моделирование является основой для более сложных задач, связанных с оптимизацией и проектированием сварочных процессов. Удобный графический интерфейс содержит автоматические процедуры, позволяющие подготовить входные данные, ускорить построение модели, выполнить численные расчёты (моделирование), а также представить результаты сварочных процессов. После выполнения моделирования программа позволяет отображать кривые параметров динамического процесса в зависимости от времени (например, формы напряжения, тока, мощности и сопротивления, изменения силы и хода электрода, увеличения диаметра сварного шва и т. д.). В процессе сварки система обеспечивает визуализацию распределения температуры, тока, напряжения, твёрдости, а также деформаций и напряжений во всех материалах (элементах данной модели). The SORPAS®system uses the finite-element method to create numerical models enable to simulate contact welding processes. Simulation of welding processes is carried out to determine (test) the weldability of new materials by predicting the results arising during the use of specific base materials, electrode materials and parameters of the welding process. Simulation is the basis for more complex tasks related to the optimization and design of welding processes. The convenient graphic interface contains automatic procedures that allow you to prepare input data, speed up the model building, perform numerical calculations (modeling) and also present the results of welding processes. After the simulation the program allows you to display dynamic process parameter curves depending on time (for example, the shape of the voltage, current, power and resistance, changes in the force and stroke of the electrode, an increase in the diameter of the weld, etc.). During the welding process the system provides visualization of the distribution of temperature, current, voltage, hardness as well as deformations and stresses in all materials (elements of this model).


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