Method for preparing silver-tungsten carbide contact material from silver-coated tungsten carbide powder and silver-tungsten carbide contact material

A technology of silver-coated tungsten carbide and silver tungsten carbide, which is used in contacts, electrical components, electrical switches, etc., can solve the problems of unstable composition, uneven penetration of silver flakes, uneven metallographic structure of contact materials, etc.

Active Publication Date: 2014-05-28
WENZHOU LONGSUN ELECTRICAL ALLOY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The traditional mechanical powder mixing method is to mix silver powder and tungsten carbide powder through a powder mixer. Since the surface of tungsten carbide particles has the characteristics of hard alloy, the surface wettability is poor, and the affinity between the particles is poor when mixed with silver powder particles, which is easy to cause the powder to mix incorrectly. Uniform, in the subsequent sintering and infiltration process, the infiltration of silver flakes is uneven, resulting in segregation, resulting in uneven metallographic structure, unstable composition, high resistivity and other quality problems of the contact material, which affect the service life of the electrical contact material

Method used

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  • Method for preparing silver-tungsten carbide contact material from silver-coated tungsten carbide powder and silver-tungsten carbide contact material
  • Method for preparing silver-tungsten carbide contact material from silver-coated tungsten carbide powder and silver-tungsten carbide contact material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] 1. Prepare Ag50WC50 coating powder 5Kg

[0026] 1.1. Ag required for material preparation: 5×50%=2.5 Kg, thus calculating AgNO3 crystal: 2.5 / 0.6351=3.936 Kg (0.6351 is the molar mass ratio of silver to silver nitrate);

[0027] Required WC powder: 5×50%=2.5 Kg,

[0028] Required Cu powder: 2.5 / 3.4=0.735 Kg (from the replacement reaction equation, it is estimated that 1g of Cu replaces Ag by about 3.4g);

[0029] 1.2. Add 3.936 Kg of AgNO3 crystals into deionized water at 25-45°C, stir and dissolve with stainless steel to obtain AgNO3 solution, so that the molar concentration of AgNO3 solution is 5-7mol / L;

[0030] 1.3. Put WC powder and Cu powder into the reaction tank, add 10-15L of deionized water at 25-45°C, and stir evenly for 5 minutes to obtain a mixed aqueous solution;

[0031] 1.4. Slowly add the AgNO3 solution into the mixed aqueous solution under constant stirring until the AgNO3 solution is completely added, and continue to stir for 3 to 5 minut...

Embodiment 2

[0044] 1. Prepare Ag47WC53 coating powder 5Kg

[0045] 1.1. Ag required for material preparation: 5×47%=2.35 Kg, thus calculating AgNO3 crystal: 2.35 / 0.6351=3.7Kg (0.6351 is the molar mass ratio of silver to silver nitrate);

[0046] Required WC powder: 5×53%=2.65 Kg,

[0047]Required Cu powder: 2.35 / 3.4=0.691 Kg (from the replacement reaction equation, 1g of Cu replaces Ag with about 3.4g);

[0048] 1.2. Add 3.7Kg of AgNO3 crystals into deionized water at 25-45°C, stir and dissolve with stainless steel to obtain AgNO3 solution, so that the molar concentration of AgNO3 solution is 5-7mol / L;

[0049] 1.3. Put WC powder and Cu powder into the reaction tank, add 9.4-14.1L of deionized water at 25-45°C, and stir evenly for 5 minutes to obtain a mixed aqueous solution;

[0050] 1.4. Slowly add the AgNO3 solution into the mixed aqueous solution under constant stirring until the AgNO3 solution is completely added, and continue to stir for 3 to 5 minutes to carry out a chemica...

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Abstract

The invention discloses a method for preparing a silver-tungsten carbide contact material from silver-coated tungsten carbide powder and the silver-tungsten carbide contact material. According to the technical scheme, a silver-tungsten carbide electrical contact is prepared from raw materials, i.e., a silver nitrate crystal and tungsten carbide powder, by a chemical coating powder preparation process and a liquid-phase infiltration process; the prepared silver-tungsten carbide electrical contact comprises the following components in percentage by weight: 38%-42% of tungsten carbide, 0-0.2% of additives and the balance being silver, wherein the additives are one or more selected from nickel, copper and zirconium. The silver-tungsten carbide contact material prepared by the method has the advantages of high density, high hardness, low and stable contact resistance, uniform metallographic structure, favorable high-temperature oxidation resistance, electric arc erosion resistance, wear resistance and the like.

Description

technical field [0001] The invention relates to the technical field of powder metallurgy electrical contact materials, in particular to a method for preparing silver-tungsten carbide contact materials from silver-coated tungsten carbide powder. Background technique [0002] The electrical contact is a key component of the switching device, which undertakes the function of conducting current, and its performance directly affects the reliability and service life of the switching device. Therefore, the switching device requires that the electrical contact should have good electrical and thermal conductivity, low contact resistance and Features such as temperature rise, high resistance to fusion welding and electrical corrosion resistance. [0003] In recent years, the miniaturization of electrical switches has made the temperature rise of electrical contacts unable to meet the miniaturization of electrical contacts under working conditions, so the electrical contacts are requir...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01H1/0233H01H11/04
Inventor 冯如信罗小虎
Owner WENZHOU LONGSUN ELECTRICAL ALLOY CO LTD
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