A Study on the Development of Environment-Friendly Ag-SnO2 Electric Contact Materials through a Powder Metallurgy

2007 ◽  
Vol 539-543 ◽  
pp. 2761-2766 ◽  
Author(s):  
Hoon Cho ◽  
Duck Young Hwang ◽  
Hyung Ho Jo
Keyword(s):  
Powder Metallurgy ◽  
Manufacturing Process ◽  
Electrical Contact ◽  
Image Analyzer ◽  
Contact Material ◽  
Electric Contact ◽  
Contact Materials ◽  
Grain Distribution ◽  
Sno2 Powder ◽  
Electric Contact Material

It is generally known that Ag-CdO electric contact material excels others in characteristics. Thus, the contact material has been widely used, regardless of current strength. However, in a view point of environment, the advanced electric contact material without environmental load element such as cadmium has to be developed. Extensive studies have been carried out on Ag-SnO2 electric contact material as a substitute of Ag-CdO contact materials. In the manufacturing process of Ag-SnO2 electric contact material, it can be mentioned that typical internal oxidation process is not suitable to produce Ag-SnO2 electric contact material because the Sn located around surface may interrupt oxidation of Sn in the middle of material. Therefore, in the present study, powder metallurgy including compaction and sintering is introduced to solve the incomplete oxidation problems in manufacturing process of Ag-SnO2 electrical contact material. The formation of the blends was manufactured by wet blending of powders of Ag and SnO2. The quantity of SnO2 powder was 15wt.%, with intent to optimize the powdering process for the minute powder of which diameter is less than 5μ m. Particle size and grain distribution of Ag powder and SnO2 powder by powder metallurgy were measured by image analyzer. In order to estimate the properties of specimen tested with a variation of mixed time, the micro-hardness measurement was carried out. The Ag-SnO2-based contact material, which was produced through this study, was actually set in an electric switchgear of which working voltage is 462V and current is between 25 and 40A, for the purpose of testing its performance. As the result, it excelled the existing Ag-CdO-based contact materials in terminal-temperature ascent and main contact resistance.

Evaluation of Electrical Contact Material Stability on Mercuric Iodide

1993 ◽  
Vol 302 ◽  
Author(s):  
A. Y. Cheng
Keyword(s):  
Free Energy ◽  
Room Temperature ◽  
Electrical Contact ◽  
Radiation Detection ◽  
Electrical Contacts ◽  
Contact Material ◽  
Mercuric Iodide ◽  
Energy Data ◽  
Contact Materials ◽  
Temperature Radiation

ABSTRACTMercuric iodide detectors are leading candidates for room-temperature radiation detection applications. The inherently reactive nature of mercuric iodide limits the number of materials suitable for fabrication of electrical contacts. The theoretical stabilities of elemental contact materials on mercuric iodide were evaluated at 25°C. Additionally, the stabilities of transparent conductive compounds, for photodetector applications, were studied. Calculations were based on Gibbs free energy data, estimates and a series of hypothesized reactions with mercuric iodide. Leading candidate materials were identified and compared to experimental results.

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.

Copper-Based Electronic Materials Prepared by SPS and their Properties

2010 ◽  
Vol 97-101 ◽  
pp. 1730-1735
Author(s):  
Zhong Quan Guo ◽  
Hao Ran Geng ◽  
Bao Chuan Sun
Keyword(s):  
Powder Metallurgy ◽  
Electronic Materials ◽  
Electrical Contact ◽  
Compression Force ◽  
Contact Materials ◽  
Comprehensive Properties ◽  
Sintering Time ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Electrical Contact Materials

Copper-based electrical contact materials were prepared by Spark Plasma Sintering (SPS) method and powder metallurgy with the addition of different proportions of rare earth (RE) element. It is found that SPS method greatly enhances the density, hardness and conductivity of the composite materials, thus improving their comprehensive properties. Compared with powder metallurgy, SPS boasts a shorter sintering time, smaller compression force and higher efficiency. RE has considerable influence on the comprehensive properties of copper-based electrical contact materials. When the content of RE lower than 0.1%, the comprehensive properties can be improved by increasing RE.

scholarly journals Comparative Study of the Properties of Cu-Cr-Mo System Electrical Contact Material by Sintering and Infiltration Methods

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 700
Author(s):  
Yeong-Woo Cho ◽  
Jae-Jin Sim ◽  
Jong-Soo Byeon ◽  
Taek-Soo Kim ◽  
Kee-Ahn Lee ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Relative Density ◽  
High Voltage ◽  
Raw Materials ◽  
Electrical Contact ◽  
Green Compact ◽  
Contact Material ◽  
Mixed Powder ◽  
Contact Materials ◽  
Infiltration Method

Contact materials in high-voltage vacuum interrupters require properties such as high conductivity, density and hardness to minimize arc heat damage. In this study, Cu–Cr–Mo alloy contact materials were examined for their usage as high-voltage contact materials. Ball milling was performed after analyzing the raw materials of the Cu, Cr and Mo powders. A green compact was produced using high pressure with a mixed powder. Subsequently, the composite was produced by sintering via the temperature and infiltration method according to the Cu content in the green compact. The composite sintering method produced a density of 8.55 g/cm3 (relative density 93%), a hardness of 217 HV and an electrical conductivity of 40.7% IACS at 1200 °C. The composite of 10 wt.% Cu produced by the Cu infiltration method exhibited a density of 8.7 g/cm3 (relative density 94%), hardness of 274 HV and electrical conductivity of 39 IACS% at 1300 °C. The measurements of the physical properties of our newly established method demonstrated a new possibility of using the Cu–Cr–Mo alloy as a contact material for high-voltage vacuum interrupters.

scholarly journals Parameter Characterization in Processing of Silver – Aluminum Based Electrical Contact Materials

2017 ◽  
Vol 62 (3) ◽  
pp. 1895-1901 ◽  
Author(s):  
S. Praveen Kumar ◽  
R. Parameshwaran ◽  
A. Ananthi ◽  
J. Jenil Jaba Sam
Keyword(s):  
Powder Metallurgy ◽  
Tin Oxide ◽  
Electrical Contact ◽  
Cadmium Oxide ◽  
Aluminum Matrix ◽  
Stir Casting ◽  
Vital Role ◽  
Contact Materials ◽  
Potential Applications ◽  
Electrical Contact Materials

AbstractAn electrical contractor is one which plays significant role in day todays life in industries as well as in home appliances. In current scenario the materials for conducting purpose has an overwhelming research capability. Now a day the silver based electrical contact composite material have provided the potential applications in aerospace and automobile industries. Among silver based contact material the silver cadmium oxide and silver tin oxide plays a vital role in fabrication of electrical contactors. In this research an attempt has been made to study the influence of adding Aluminum with silver based electrical contact composite materials by two different processing routes namely stir-casting and powder metallurgy. Silver and aluminum matrix plays a virtual role in composite world owing to their highest conductivity. Optimum parameters were identified for attaining the maximum properties such as conductivity, hardness, density, and porosity of composition. By this better conducting property and mechanical property of the electrical contact can be improved by this system. Thus a screening test has be conducted with addition of Al with silver tin oxide compositions hence this paper aims to process the aluminum - silver based electrical contact materials by stir casting processing and powder metallurgy route and compare the results obtained.

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