Process for preparing nano chromium carbide powder

A nano-chromium carbide and powder technology, which is applied in chemical instruments and methods, inorganic chemistry, chromium compounds, etc., can solve the problems of high carbonization temperature, coarse particle size, and long carbonization time, and achieve uniform particle size distribution and simple equipment.

Inactive Publication Date: 2007-12-26
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the principle of coarse particle size, high carbonization temperature and long carbonization time of the traditional method, the prepared Cr 3 C 2 The particle size of the powder is relatively coarse, generally 2-5 μm

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Embodiment 1: the preparation average particle diameter is the nano-Cr of 90nm 3 C 2 Powder, should be done according to the following steps.

[0022] 1. Ammonium dichromate hydrate ((NH 4 ) 2 Cr 2 o 7 ·7H 2 O) dissolved in deionized water, prepared as a 2mol / L aqueous solution.

[0023] 2. Pour the ammonium dichromate aqueous solution into the reaction kettle, heat to 50°C, add hydrazine hydrate dropwise to excess, a violent reaction occurs to form a dark green colloidal precipitate.

[0024] 3. The precipitate is suction filtered, placed in a vacuum oven, and dried at 150°C for 2 hours to obtain light green nano-Cr 2 o 3 powder with a BET specific surface of 31.3m 2 / g, the SAXS average particle diameter is 35.5nm.

[0025] 4. Nano-Cr per kg 2 o 3 Adding 300g nanometer carbon black and 350ml concentration is the ratio of the phenolic resin ethanol solution of 0.2g / ml in the powder, will Cr 2 o 3 The powder and nano-carbon black were ball milled on a plan...

Embodiment 2

[0029] Embodiment 2: the preparation of average particle diameter is the nano-Cr of 70nm 3 C 2 Powder, should be done according to the following steps.

[0030] 1. Ammonium dichromate hydrate ((NH 4 ) 2 Cr 2 o 7 ·7H 2 O) dissolved in deionized water, prepared as a 1mol / L aqueous solution.

[0031] 2. Pour the ammonium dichromate aqueous solution into the reaction kettle, heat to 70°C, add hydrazine hydrate dropwise to excess, a violent reaction occurs to form a dark green colloidal precipitate.

[0032] 3. The precipitate is suction filtered, placed in a vacuum oven, and dried at 150°C for 2 hours to obtain light green nano-Cr 2 o 3 Powder, its BET specific surface is 45.4m 2 / g, the SAXS average particle diameter is 22.6nm.

[0033] 4. Nano-Cr per kg 2 o 3 Adding 250g nanometer carbon black and 350ml concentration is the ratio of the phenolic resin ethanol solution of 0.4g / ml in the powder, will Cr 2 o 3 The powder and nano-carbon black were ball milled on a pla...

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PUM

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Abstract

The invention provides a Method for preparation of nanochromium carbide powder, belonging to nanometal carbide powder preparation technical realm. Using ammonium dichromate, hydrazine hydrate, nanocarbon black and formaldehyde-phenol resin as raw material, first deoxidizing ammonium dichromate in aqueous solution by hydrazine hydrate and getting the amorphous nanoCr2O3, and then mixing nanoCr2O3, nanocarbon black and formaldehyde-phenol resin, getting nanoCr2O3 after 800-1100 Deg C heat treatment in vacuum furnace. The advantages of this invention are lies in: realizing the granularity of chromium carbide powder can controlled, the technics and equipment is simple and is the same with industrialization production.

Description

technical field [0001] The invention belongs to the technical field of nanometer metal carbide powder preparation, and in particular provides a preparation method of nanometer chromium carbide powder. Background technique [0002] Cr 3 C 2 Powder has a wide range of uses in the powder metallurgy industry, for example, when preparing tungsten carbide-based ultrafine cemented carbide, Cr 3 C 2 The powder can be used as a highly effective grain growth inhibitor without affecting the alloy strength. Another example is Cr 3 C 2 -NiCr coating has high resistance to high temperature oxidation, corrosion resistance and wear resistance. [0003] Preparation of Cr 3 C 2 The traditional method of powder is to mix and ball-mill Cr oxide with solid carbon, and then carbonize the mixture. Due to the principle of coarse particle size, high carbonization temperature and long carbonization time of the traditional method, the prepared Cr 3 C 2 The particle size of the powder is rel...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01G37/00C01B31/30
Inventor 郝俊杰罗骥郭志猛林涛胡学晟
Owner UNIV OF SCI & TECH BEIJING
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