A kind of preparation method of ultra-coarse spherical tungsten powder

A tungsten powder and spherical technology, which is applied in the field of preparation of ultra-coarse spherical tungsten powder, can solve problems such as poor fluidity, difficulty in powder feeding, and too fine powder, and achieve good fluidity, fast heat transfer and cooling speed, and high sphericity Effect

Active Publication Date: 2017-12-22
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problem of difficulty in feeding powder due to too fine raw material powder and poor fluidity when preparing spherical tungsten powder

Method used

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  • A kind of preparation method of ultra-coarse spherical tungsten powder
  • A kind of preparation method of ultra-coarse spherical tungsten powder
  • A kind of preparation method of ultra-coarse spherical tungsten powder

Examples

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Embodiment example 1

[0022] 1. Preparation of Precursor Powder

[0023] Using conventional tungsten powder as raw material, granulate with 5wt.% polyvinyl alcohol (PVA) solution, the addition amount is 4wt.%, vacuum dry at 60°C for 1 hour after granulation, and sieve to obtain precursor powder.

[0024] 2. Preparation of ultra-coarse spherical tungsten powder

[0025] Before the radio frequency plasma starts arcing, the diffusion pump unit is pre-evacuated to 1.0×Pa to prevent tungsten and oxygen from reacting to form tungsten oxide. The main process parameters of RF plasma are: argon is used as working gas, side gas and carrier gas, working gas flow rate is 30 slpm, side gas flow rate is 100 slpm, system negative pressure is 200 mm Hg, carrier gas flow rate is 4 slpm, powder feeding rate is 10 g / min, the equipment output power is 45KW. After the obtained precursor powder is sent into the plasma high-temperature zone, the precursor powder absorbs heat, melts and spheroidizes, and is quenched an...

Embodiment example 2

[0027] 1. Preparation of Precursor Powder

[0028] Using conventional tungsten powder as raw material, granulate with 5wt.% polyvinyl alcohol (PVA) solution, the addition amount is 4wt.%, vacuum dry at 60°C for 1 hour after granulation, and sieve to obtain precursor powder.

[0029] 2. Preparation of ultra-coarse spherical tungsten powder

[0030] Before the radio frequency plasma starts arcing, the diffusion pump unit is pre-evacuated to 1.0×Pa to prevent tungsten and oxygen from reacting to form tungsten oxide. The main process parameters of RF plasma are: argon is used as working gas, side gas and carrier gas, working gas flow rate is 35 slpm, side gas flow rate is 120 slpm, system negative pressure is 240 mm Hg, carrier gas flow rate is 5 slpm, powder feeding rate is 30 g / min, the output power of the equipment is 60KW. After the obtained precursor powder is sent into the plasma high-temperature zone, the precursor powder absorbs heat, melts and spheroidizes, and is quen...

Embodiment example 3

[0032] 1. Preparation of Precursor Powder

[0033] Using conventional tungsten powder as raw material, granulate with 5wt.% polyvinyl alcohol (PVA) solution, the addition amount is 4wt.%, vacuum dry at 60°C for 1 hour after granulation, and sieve to obtain precursor powder.

[0034] 2. Preparation of ultra-coarse spherical tungsten powder

[0035] Before the radio frequency plasma starts arcing, the diffusion pump unit is pre-evacuated to 1.0×Pa to prevent tungsten and oxygen from reacting to form tungsten oxide. The main process parameters of RF plasma are: argon is used as working gas, side gas and carrier gas, working gas flow rate is 30 slpm, side gas flow rate is 100 slpm, system negative pressure is 220 mm Hg, carrier gas flow rate is 4 slpm, powder feeding rate is 20 g / min, the equipment output power is 50KW. After the obtained precursor powder is sent into the plasma high-temperature zone, the precursor powder absorbs heat, melts and spheroidizes, and is quenched an...

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Abstract

The invention provides a preparation method for ultra-coarse spherical tungsten powder and belongs to the technical field of powder preparation. Conventional tungsten powder is selected as a raw material, polyving akohol (PVA) pelleting, vacuum drying and screening are conducted, and large-particle precursor powder is obtained; and when passing a radio frequency plasma body high-temperature region, the precursor powder is subjected to heat absorption, melting and spheroidizing and then subjected to shock cooling and curing, and the spherical powder is obtained. The prepared spherical tungsten powder is large in grain size, uniform in component, high in sphericility, good in liquidity and low in oxygen content and meets the process requirements of a laser near-net forming technology and a shaped charge liner manufacturing technology. The preparation method has the beneficial effect that the problems that when the spherical tungsten powder is prepared, due to the fact that the raw material powder is too fine, liquidity is poor, and powder conveying is difficult are solved effectively.

Description

technical field [0001] The invention belongs to the technical field of powder preparation, and in particular provides a preparation method of ultra-coarse spherical tungsten powder. technical background [0002] Metal tungsten has excellent properties such as high melting point, high hardness, low expansion coefficient, good corrosion resistance and thermal electron emission capability, and is widely used in many fields such as aerospace, military industry and electronics industry. [0003] With the development of science and technology, the requirements for raw material tungsten powder are constantly increasing, while conventional tungsten powder particles are irregular in shape, not only has low bulk density, but also has poor powder fluidity, which limits its application. Spherical tungsten powder has been paid more and more attention in industrial production because of its good fluidity and high bulk density. In the field of thermal spraying, ultra-coarse spherical tung...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): B22F9/14B22F9/06
CPCB22F9/06B22F9/14B22F2009/065
Inventor郝俊杰舒进锋郭志猛吴成义龙海明吴立成李伸
OwnerUNIV OF SCI & TECH BEIJING