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A kind of preparation method of polyhedral tungsten powder

A technology of polyhedron and tungsten powder, which is applied in metal processing equipment, transportation and packaging, etc., can solve the problem that the shape of tungsten powder cannot be controlled, and achieve the effect of uniform shape and particle size, high microhardness and few defects

Active Publication Date: 2022-05-06
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The reduction of tungsten trioxide with hydrogen to prepare tungsten powder has a disadvantage. When tungsten trioxide is reduced at high temperature, the original microscopic morphology will also be changed due to the effect of "volatility-deposition", so that it is impossible to control the morphology of the oxide. To achieve the purpose of controlling the morphology of tungsten powder

Method used

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  • A kind of preparation method of polyhedral tungsten powder
  • A kind of preparation method of polyhedral tungsten powder
  • A kind of preparation method of polyhedral tungsten powder

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Step 1. Mix ammonium tungstate and sodium chloride evenly in ultrapure water at a molar ratio of 1:0.5, stir and evaporate to dryness with a magnetic stirrer, and grind to obtain a mixed powder of ammonium tungstate and sodium chloride ;

[0027] Step 2: Take the obtained mixed powder and place it in a porcelain boat, and in a tube furnace with an argon atmosphere as a protection, uniformly heat up to 400°C for 30 minutes at high temperature and calcinate to obtain a mixed powder of tungsten trioxide and sodium chloride;

[0028] Step 3: After the calcination is completed, continue to raise the temperature evenly, change the atmosphere in the furnace to hydrogen, place the mixed powder of tungsten trioxide and sodium chloride at 850°C for reduction, and cool with the furnace;

[0029] In the process of cooling with the furnace, the cooling medium of the part that cools down from a higher temperature is hydrogen. When the temperature in the furnace drops to about 200°C, ...

Embodiment 2

[0033] Step 1. Mix ammonium tungstate and sodium chloride evenly in ultrapure water at a molar ratio of 1:1, stir and evaporate to dryness with a magnetic stirrer, and grind to obtain a mixed powder of ammonium tungstate and sodium chloride ;

[0034] Step 2: Take the obtained mixed powder and place it in a porcelain boat, and in a tube furnace with an argon atmosphere as a protection, uniformly heat up to 400°C for 30 minutes at high temperature and calcinate to obtain a mixed powder of tungsten trioxide and sodium chloride;

[0035] Step 3: After the calcination is completed, continue to raise the temperature evenly, change the atmosphere in the furnace to hydrogen, place the mixed powder of tungsten trioxide and sodium chloride at 850°C for reduction, and cool with the furnace;

[0036] In the process of cooling with the furnace, the cooling medium of the part that cools down from a higher temperature is hydrogen. When the temperature in the furnace drops to about 200°C, th...

Embodiment 3

[0040] Step 1. Mix ammonium tungstate and sodium chloride evenly in ultrapure water at a molar ratio of 1:2, stir and evaporate to dryness with a magnetic stirrer, and grind to obtain a mixed powder of ammonium tungstate and sodium chloride ;

[0041] Step 2: Take the obtained mixed powder and place it in a porcelain boat, and in a tube furnace with an argon atmosphere as a protection, uniformly heat up to 400°C for 30 minutes at high temperature and calcinate to obtain a mixed powder of tungsten trioxide and sodium chloride;

[0042] Step 3: After the calcination is completed, continue to raise the temperature evenly, change the atmosphere in the furnace to hydrogen, place the mixed powder of tungsten trioxide and sodium chloride at 850°C for reduction, and cool with the furnace;

[0043] In the process of cooling with the furnace, the cooling medium of the part that cools down from a higher temperature is hydrogen. When the temperature in the furnace drops to about 200°C, th...

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Abstract

The invention provides a preparation method of polyhedral tungsten powder. In the method, ammonium tungstate and sodium chloride are mixed evenly in water, stirred and evaporated to dryness, and then the obtained mixed powder is placed in a tube furnace, and firstly heated in an argon atmosphere. Calcining at high temperature to decompose ammonium tungstate into tungsten trioxide, and then raise it to a higher temperature under hydrogen atmosphere to reduce polyhedral tungsten powder. The process used in the present invention is simple and efficient, and the prepared tungsten powder is a hexahedron or dodecahedron with a micron particle size, which can be widely used in cathode emission materials, geological mining tools, oil drill bits, hard wear-resistant materials, etc. An important raw material for the preparation of other tungsten-based materials.

Description

technical field [0001] The invention relates to metal powder preparation technology, in particular to a preparation method of polyhedral tungsten powder Background technique [0002] The production of metal tungsten powder is a key step in the production of metal tungsten and tungsten alloys. To a large extent, the performance of tungsten powder affects the performance of tungsten and its alloy products in terms of pressing, sintering and processing. Among them, the formability of powder is of great significance to the preparation of tungsten and its alloy products. At present, the methods of preparing tungsten powder at home and abroad mainly include mechanical ball milling method, spray drying method, sol-gel method, physical chemical method and plasma physicochemical method, and the tungsten powder prepared by different methods has its own characteristics. Taking the mechanical ball milling method as an example, the tungsten powder prepared by this method has coarse part...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B22F9/22B22F1/06B22F1/145
CPCB22F1/0007B22F9/22B22F1/14
Inventor 吴壮志王德志杨刘熠熠刘新利段柏华
Owner CENT SOUTH UNIV
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