A method for preparing niobium-tungsten binary composite carbide nanopowder

A binary composite and carbide technology, applied in the field of powder metallurgy, can solve the problems of fine powder particles, difficulty in preparing nano-tungsten carbide powder, uneven mixing of inhibitors, etc., and achieve the effect of fine grain size and high purity

Active Publication Date: 2019-03-05
GANZHOU NONFERROUS METALLURGICAL RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This technology subverts the traditional simple mechanical mixing process of raw material tungsten carbide powder and inhibitor niobium carbide powder, and realizes the mixing of niobium-tungsten binary composite carbide at the molecular scale. Not only the powder particles are fine, but also the chemical uniformity and purity are very high. , which solves the problem of difficult preparation of nano-tungsten carbide powder and uneven mixing of inhibitors. The powder can be used to prepare ultra-fine / nanocrystalline cemented carbide

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] Example 1 Preparation of Nb-30wt%W ultrafine / nano-niobium-tungsten binary composite carbide powder

[0042] (1) Preparation of sol solution

[0043] Weigh 1276g of ammonium paratungstate with 5 crystal water (5(NH 4 ) 2 O-12WO 3 -5H 2 O), and dissolve it in 30L fluoroniobate solution, then add 300ml of surfactant PEG-600, stir well to obtain the sol solution; the fluoroniobate concentration is 100g / L as niobium oxide, and the HF acid concentration is 1.2mol / L.

[0044] (2) Ammonia neutralization precipitation

[0045] Slowly add concentrated ammonia water with a concentration of 9.6N to the sol solution until the pH value of the solution = 9-10, stop adding ammonia water, and let it stand for 30 minutes; keep stirring the solution during the ammonia water addition process.

[0046] (3) Suction filter washing

[0047] The precipitate after ammonia neutralization is filtered with a suction filter, and the precipitate is fully washed with ammonia hot pure water until the fluorine c...

Embodiment 2

[0056] Example 2 Preparation of Nb-50wt%W ultrafine / nano-niobium-tungsten binary composite carbide powder

[0057] (1) Preparation of sol solution

[0058] Weigh 2332g of ammonium paratungstate (5(NH 4 ) 2 O-12WO 3 -5H 2 O), and dissolve it in 30L fluoroniobate solution, then add 300ml of surfactant PEG-600, stir evenly to obtain the sol solution; the fluoroniobate concentration is 80g / L as niobium oxide, and the HF acid concentration is 1.0mol / L.

[0059] (2) Ammonia neutralization precipitation

[0060] Slowly add concentrated ammonia water with a concentration of 9.6N to the sol solution until the pH value of the solution = 9-10, stop adding ammonia water, and let it stand for 30 minutes; keep stirring the solution during the ammonia water addition process.

[0061] (3) Suction filter washing

[0062] The precipitate after ammonia neutralization is filtered with a suction filter, and the precipitate is fully washed with ammonia hot pure water until the fluorine content in the precip...

Embodiment 3

[0071] Example 3 Preparation of Nb-70wt%W ultrafine / nano-niobium-tungsten binary composite carbide powder

[0072] (1) Preparation of sol solution

[0073] Weigh 1488g of ammonium paratungstate with 5 crystal water (5(NH 4 ) 2 O-12WO 3 -5H 2 O), and dissolve it in 30L fluoroniobate solution, then add 300ml of surfactant PEG-600, stir evenly to obtain the sol solution; the fluoroniobate concentration is 50g / L as niobium oxide, and the HF acid concentration is 0.7mol / L.

[0074] (2) Ammonia neutralization precipitation

[0075] Slowly add concentrated ammonia water with a concentration of 9.6N to the sol solution until the pH value of the solution = 9-10, stop adding ammonia water, and let it stand for 30 minutes; keep stirring the solution during the ammonia water addition process.

[0076] (3) Suction filter washing

[0077] The precipitate after ammonia neutralization is filtered with a suction filter, and the precipitate is fully washed with ammonia hot pure water until the fluorine ...

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Abstract

The invention discloses a method for preparing niobium-tungsten binary complex carbide nano powder. The method comprises the following steps: S1, putting tungstate into a fluorine-niobium acid solution, further adding a surfactant till the pH value is 9-12, leaving to stand, aging, and filtering; S2, collecting niobium-tungsten precursor precipitate, and washing; S3, drying washed precipitate, and grinding and screening so as to obtain niobium-tungsten precursor complex powder; S4, performing reduction treatment on the niobium-tungsten precursor complex powder so as to obtain niobium oxide-tungsten complex powder; S5, selecting actual carbon addition coefficients; S6, adding carbon, and uniformly mixing with raw material powder; S7, putting uniformly mixed powder in a graphite boat or a ceramic boat loosely, performing carbonization treatment, and cooling and discharging from a furnace after treatment is completed; and S8, grinding and screening the discharged niobium-tungsten complex carbide, thereby obtaining the niobium-tungsten binary complex carbide powder. By adopting the method, mixing of niobium-tungsten binary complex carbide of a molecular grade is achieved, and the niobium-tungsten binary complex carbide powder is not only fine in granule, but also very high in chemical uniformity and purity.

Description

Technical field [0001] The invention relates to the technical field of powder metallurgy, in particular to a method for preparing ultrafine / nano niobium tungsten binary composite carbide powder by adopting chemical coprecipitation-hydrogen reduction-carbonization. Background technique [0002] Tungsten carbide is the most commonly used hard phase of cemented carbide. WC-Co cemented carbide is widely used in machining, petroleum, mining, molds due to its high strength, hardness, and excellent wear resistance and oxidation resistance. And structural wear parts and other fields. Ultra-fine-grained cemented carbide effectively solves the contradiction between the hardness and strength of traditional cemented carbide. It has higher strength, hardness and wear resistance, and meets the development of modern industry and special difficult-to-process materials. It is widely used Production of micro drills for integrated circuit boards, dot matrix printer drills, cutting tools for diffic...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B32/907B82Y30/00
CPCB82Y30/00C01P2002/60C01P2004/61
Inventor 张金祥欧阳希周健袁德林卓海鸥文小强
Owner GANZHOU NONFERROUS METALLURGICAL RES INST
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