Process for preparing nano chromium carbide powder

A nano-chromium carbide and powder technology, which is applied in the field of metallurgy, can solve the problems of slow atomic migration, small powder surface area, and low surface activation energy, and achieve the effects of reducing free carbon content, lowering carbonization temperature, and expanding applications

Inactive Publication Date: 2006-01-25
CENT SOUTH UNIV
View PDF0 Cites 16 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In industrial applications, chromium carbide powder with finer particle size and more uniform composition is often required. At present, when preparing ultra-fine cemented carbide, the particle size of WC powder is 0.2 to 0.4 microns. If the powder particle size is 2 to 5 microns, the chromium carbide powder is Grain inhibitor due to coarse grained Cr 3 C 2 The powder is smaller than the surface, the surface activation energy is low, and the atomic migration speed is slow, so its effect of inhibiting grain growth is difficult to fully exert, and the performance of ultrafine cemented carbide is difficult to further improve

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0006] Example 1: First add 4.96 grams of Cr to a solution of 15.6 grams of organic matter dissolved in 100ml deionized powder 2 o 3 , the solution concentration is 17-19%; then the solution is spray-dried in a centrifugal spray dryer, the air inlet temperature: 250°C-350°C, the air outlet temperature: 150°C, the rotating speed is 30000rpm, and the flow rate is 30ml / min. Amorphous powder of chromium complex and free organic matter, the powder shape is porous and loose spherical. Then the powder is roasted at 500°C to 600°C in a protective atmosphere, and the chromium complex and free organic matter are decomposed to obtain Cr 2 o 3 The powder mixed evenly with free C atomic level, and then at 850-1000°C, H 2 / CH 4 Reduction / carbonization in the atmosphere for 40-90 minutes to obtain nano-Cr with a narrow particle size distribution and an average particle size of 0.1 microns 3 C 2 powder.

example 2

[0007] Example 2: First add 6.4 grams of CrO to a solution of 15.5 grams of organic matter dissolved in 100ml deionized water 3 , to obtain a clear and transparent solution, the concentration of the solution is 18-20%; then the solution is spray-dried in a centrifugal spray dryer, the air inlet temperature: 250°C-350°C, the air outlet temperature: 150°C, the speed 30000rpm, the flow rate 30ml / min, the amorphous powder containing chromium complex and free organic matter is obtained, and the powder shape is porous and loose spherical. Then the powder is melted at 500°C to 600°C, and the tungsten complex and free organic matter are decomposed to obtain WO 3 A powder that is uniformly mixed with free C atoms; this powder is stored at 850-900°C in H 2 / CH 4 Medium reduction / carbonization for 40-90 minutes can produce ultra-fine WC powder with narrow particle size distribution and an average particle size of 0.2 microns.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

A process for preparing chromium carbide nano-particles includes such steps as dissolving Cr2O3 in organic solution, spray drying to obtain spherical hollow porous particles, calcining at 500-600 deg. C in protecting atmosphere, and carbonizing in H2 / CHCP at 850-1000 deg. C for 40-90 min.

Description

Technical field: [0001] The invention belongs to the preparation process of metal powder in the field of metallurgy, in particular to the preparation method of nanometer chromium carbide powder. Background technique: [0002] Chromium carbide has been widely used in industry as an ultrafine cemented carbide grain inhibitor and the main component of spray powder. At present, the preparation of chromium carbide generally adopts Cr 2 o 3 It is mixed with carbon black and carbonized, and the particle size of the obtained chromium carbide is micron. In industrial applications, chromium carbide powder with finer particle size and more uniform composition is often required. At present, when preparing ultra-fine cemented carbide, the particle size of WC powder is 0.2 to 0.4 microns. If the powder particle size is 2 to 5 microns, the chromium carbide powder is Grain inhibitor due to coarse grained Cr 3 C 2 The powder is smaller than the surface, the surface activation energy is ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C01B31/30
Inventor 吴恩熙颜练武钱崇梁曾青
Owner CENT SOUTH UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap