A New Silver-Based Graded Composite as Electrical Contact Material

2007 ◽  
Vol 336-338 ◽  
pp. 2616-2618 ◽  
Author(s):  
Lu Wang ◽  
Yong Zhao ◽  
X.T. Zhu ◽  
Y. Wang
Keyword(s):  
Surface Layer ◽  
Metal Oxides ◽  
Contact Surface ◽  
Electrical Contact ◽  
Functionally Graded ◽  
Operating Parameters ◽  
Contact Material ◽  
Contact Materials ◽  
Electrical Contact Material ◽  
Graded Material

Silver metal oxides (Ag/MeO) are extensively used as electrical contact materials in switching systems. A contact material with ideal operating parameters is very difficultly fabricated by conventional manufacturing techniques. In this paper, a new electrical contact material characterized by graded distributions of different oxides in Ag matrix was fabricated in order to optimize the distributions of operating parameters in material bulk instead of to enhance synchronously properties of that on contact surface. Two selected metal oxides, NiO and SnO2, were doped into Ag matrices, of which one surface layer NiO 12wt% was doped and another SnO2 12wt%, and the concentrations of NiO and SnO2 were varied gradually in bulk. The electrical contact test results show that the average operating number of NiO doped surface layer of graded Ag composite as contact surface is 4600 under 20A current and 220V AC voltage without melted welding while that of samples doped uniformly with NiO is 2200 under the same testing conditions. However, the average loss of mass due to arc erosion of graded samples is higher than that of uniform samples. We conclude that the functionally graded material (FGM) concept has potential application for electric contact materials.

The Preparation and Properties of New Silver-Metal Oxide Graded Composite Electrical Contact Materials

2007 ◽  
Vol 280-283 ◽  
pp. 1917-1920 ◽  
Author(s):  
Yu Wang ◽  
F. Zhang ◽  
L.Z. Qi ◽  
L. Wang ◽  
L.C. Cheng
Keyword(s):  
Thermal Conductivity ◽  
Metal Oxide ◽  
Solid Phase ◽  
Electrical Contact ◽  
Functionally Graded ◽  
Physical Parameters ◽  
Contact Material ◽  
Electrical Contact Material ◽  
Graded Material ◽  
Silver Metal

Electrical contact material is a very important material for the electric power industry. An electrical contact material should display good structural characteristics (suitable hardness, high thermal conductivity and stabilization) as well as a good functional characteristic (low electrical resistivity). It is difficult to fabricate such a contact material with all these good performing parameters by common techniques because these physical parameters influence each other. In this paper, we report a novel investigation to design and prepare silver-metal oxide composite materials according to functionally layered and graded material (FLGM) concept and meeting requirement as electrical contact material. The silver-based composite samples characterized by layered component were prepared with conventional solid-phase sintering technique. One kind of sample consists of tin dioxide and silver material, in which SnO2 exhibits a graded distribution. Another consists of two metal oxides, cadmium and zinc oxides, and silver material, in which each layer has different metal oxide. Hardness, thermal conductivity and electrical conductivity, were measured and related problems are discussed. Especially, welding resistance as an important parameter for practical application was tested. SEM analyses before and after electrical erosion were also performed. We conclude that the functionally graded material (FGM) concept as a novel designing and fabricating method has potential for electrical contact composite material.

Preparation and Study on Nano-Ag/SnO2 Electrical Contact Material Doped Rare Earth Element

2014 ◽  
Vol 789 ◽  
pp. 270-274 ◽  
Author(s):  
Yan Cai Zhu ◽  
Jing Qin Wang ◽  
Hai Tao Wang ◽  
Li Qiang An
Keyword(s):  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Electrical Contact ◽  
Sol Gel ◽  
Fusion Welding ◽  
Electrical Performance ◽  
Contact Material ◽  
Contact Materials ◽  
Electrical Contact Material

As a new type of electrical contact material, Ag/SnO2 has poor processing performance and large contact resistance, which limits its application so far. In order to improve the machinability and electrical performance of the Ag/SnO2 electrical contact materials, a new kind of nanoAg/SnO2 electrical contact material doped rare earth element Ce was prepared by sol-gel-chemical plating method. The purity of the powders was analyzed by X-ray diffraction (XRD) and the crystallite size of the nanoparticle was calculated according to the Scherrer equation. The distribution of Ce-doped SnO2 powers were studied using scanning electron microscopy (SEM). In parallel, rated making and breaking experiments on nanoAg/SnO2 were conducted. The results of XRD and SEM show that the nanoSnO2 powders are small, uniform and with no obvious phenomenon of reunion, and thus significantly improve the density, strength and machinability of the sample. Furthermore, the results of arc erosion show that the nanoAg/SnO2 electricity contact materials doped element Ce have superior fusion welding resistance properties.

Research Progress in Silver Zinc Oxide Electrical Contact Material

2021 ◽  
Vol 1036 ◽  
pp. 77-90
Author(s):  
Shang Qiang Zhao ◽  
Ming Xie ◽  
Ji Heng Fang ◽  
Yong Tai Chen ◽  
Sai Bei Wang
Keyword(s):  
Zinc Oxide ◽  
Failure Mechanism ◽  
Rapid Development ◽  
Electrical Contact ◽  
Cadmium Oxide ◽  
Research Progress ◽  
Contact Material ◽  
Contact Materials ◽  
Electrical Contact Material ◽  
Electrical Contact Materials

Since the performance of silver metal oxide (Ag/MeO) electrical contact materials directly affects the reliability and service life of switching apparatus, the related research on high-performance Ag/MeO electrical contact materials has not stopped. And with the rapid development of switching apparatus, higher and higher requirements are put forward for the performance of Ag/MeO electrical contact materials. Thanks to low and stable contact resistance, short arc burning time, good resistance to high current impulse (3000-5000 A) and good anti-arc erosion, silver zinc oxide (Ag/ZnO) more than just serves as an indispensable environmentally friendly alternative to silver cadmium oxide (Ag/CdO) electrical contact material, and has become one of the important research hotspots of Ag/MeO in recent years. Nevertheless, Ag/ZnO is suffering the increasingly serious challenges, especially the poor processability and electrical properties due to the easy segregation of zinc oxide (ZnO) during the process of preparation, which urge scholars at home and abroad to seek favorable methods to optimize the Ag/ZnO. As yet, impressive strides have been made in optimization the preparation process, nano-technology and additive modification of materials, and research on the failure mechanism of materials. Aiming to provide reference for optimizing Ag/ZnO electrical contact material, this review retrospects the research progress in Ag/ZnO electrical contact materials in recent years, and expounds the preparation methods, processing technology, modification research and failure mechanism of Ag/ZnO, and points out the future development directions of Ag/ZnO.

The Contact Resistance and Arc Erosion Behavior of Separable CP-Nb-Cr/Cu-Cd Electrical Contact Material

2007 ◽  
Vol 353-358 ◽  
pp. 886-889 ◽  
Author(s):  
Yu Sheng Cui ◽  
Liang Zhen ◽  
Y. Wang ◽  
Wen Zhu Shao ◽  
V.V. Ivanov
Keyword(s):  
Surface Layer ◽  
Contact Resistance ◽  
Electrical Contact ◽  
Composition Analysis ◽  
Contact Material ◽  
Arc Erosion ◽  
Electrical Arc ◽  
Electrical Contact Material ◽  
Microstructure Observation ◽  
Powder Metallurgy Process

CP-Nb-Cr/Cu-Cd electrical contact material, which contains 1.7wt.% of Cd, 0.5wt.% of CP (man-made diamond particles), 2.0 wt.% of Nb and 0.7 wt.% of Cr, was fabricated by powder metallurgy process. The contact material was installed in different ac contactors covering current range from 40 to 630A. While tested under AC-4 electrical load, the electrical contact material was worn out gradually by repeated electrical arc, and microstructure of the arc-affected surface layer changed dramatically. Mechanism of arc erosion process and contact resistance fluctuation was discussed by corresponding microstructure observation and chemical composition analysis of the surface layer. CP-Nb-Cr/Cu-Cd electrical contact material is capable to be used in 63~250A ac contactors under AC-4 working conditions.

Numerical Analysis on the Electrical Performance of Microstructured Environmentally-Friendly Electrical Contact Material Ag/SnO2

2013 ◽  
Vol 419 ◽  
pp. 355-359
Author(s):  
Lei Wang ◽  
Wei Li Liu ◽  
Le Sheng Chen
Keyword(s):  
Numerical Simulation ◽  
Electrical Contact ◽  
Environmentally Friendly ◽  
Weight Percent ◽  
Diameter Ratio ◽  
Electrical Performance ◽  
Structural Parameter ◽  
Contact Material ◽  
Electrical Contact Material ◽  
Length To Diameter Ratio

The paper analyzes the influence of structural parameters on the electrical performance of the microstructured environmentally-friendly electrical contact material Ag/SnO2 by using numerical simulation method.The numerical results show that the reisitivity of fiber-like electrical contact material Ag/SnO2 is significantly reduced compared with the resistivity of Ag/SnO2 adding reinforcing nanoparticles in the traditional way.So the fiber-like electrical contact material Ag/SnO2 exhibits higher conductivity in macro. On further analysis, we learn that the resistivity of fibrous electrical contact materials is related to weight percent of reinforced phase, and micro-structural parameter of length to diameter ratio. The resistivity increases as weight percent of reinforced phase increases,and decreases non-linearly with micro-structural parameter of length to diameter ratio increasing.This demonstrates that numerical simulation is one of effective methods for analysis of the electrical performance of the microstructured electrical contact material.

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