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Preparation method of dense coated composite powder and super coarse and extra coarse grained cemented carbide

A dense coating type, hard alloy technology, applied in the direction of coating, etc., can solve the problems of easy introduction of foreign impurities in electroplating, high production cost, etc.

Active Publication Date: 2013-08-28
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Methods such as CVD, Sol–Gel, and polyol liquid phase reduction have problems such as high preparation costs
Electroless plating and electroplating have problems such as easy introduction of foreign impurities, and as raw materials for cemented carbide production, they must meet the requirements of high purity
In addition, there are many reports on tungsten-cobalt double salt precipitation, spray drying to prepare tungsten-cobalt composite oxide, and direct reduction carbonization to prepare WC–Co composite powder, but this composite powder is only suitable for the preparation of ultrafine cemented carbide.

Method used

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  • Preparation method of dense coated composite powder and super coarse and extra coarse grained cemented carbide
  • Preparation method of dense coated composite powder and super coarse and extra coarse grained cemented carbide
  • Preparation method of dense coated composite powder and super coarse and extra coarse grained cemented carbide

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] The composite powder was prepared according to WC-12%Co (mass ratio). WC with a C content of 6.13% and a grain size of 6.6 μm was selected as the raw material, and W powder was added to adjust the total carbon content in the WC–12Co composite to 5.36%. W powder was mechanically activated in a mechanical activation machine for 8 h. According to 1.5 mol / L Co 2+ Molarity Dissolve cobalt chloride in deionized water. By NaOH:Co 2+ The molar ratio is 100% of the stoichiometric ratio of 2:1 to calculate the amount of NaOH added, and NaOH is dissolved in deionized water at a molar concentration of 2 mol / L. The filtered NaOH solution was transferred to the stirring reaction tank, the temperature of the reaction tank was controlled at 70°C, and the filtered cobalt chloride solution was added dropwise to the NaOH solution through 3 pipes. The reaction product cobalt hydroxide alkaline slurry is transferred to a high-pressure reactor, and at the same time, mechanically activate...

Embodiment 2

[0028] According to WC–12%Ni–0.5%Cr 3 C 2 (mass ratio) ingredients to prepare composite powder. WC with a C content of 6.13% and a grain size of 6.6 μm was selected as the raw material, and W powder was added to make WC–12Ni–0.5Cr 3 C 2 In the composite powder, the total carbon content is adjusted to 5.36%, and the mass ratio of the balls: the material is 3: 1 with WC, Cr 3 C 2 And the W powder was mechanically activated for 11 h in a mechanical activation machine. According to 1.0 mol / L Ni 2+ Molarity Nickel sulfate was dissolved in deionized water. As NaOH: Ni 2+ The molar ratio is 95% of the stoichiometric ratio of 2:1 to calculate the amount of NaOH added, and NaOH is dissolved in deionized water at a molar concentration of 3 mol / L. The filtered NaOH solution was transferred into the stirring reaction tank, and the temperature of the reaction tank was controlled at 60 °C, and the filtered nickel sulfate solution was added dropwise to the NaOH solution through thre...

Embodiment 3

[0030] Composite powder was prepared according to WC-6%Co-6%Ni (mass ratio) composition. Select WC with a C content of 6.13% and a grain size of 6.6 μm as the raw material, add W powder to adjust the total carbon content in the WC–6Co–6Ni composite powder to 5.35%, and the mass ratio of pellets:materials is 5:1 WC and W powder were mechanically activated in a mechanical activation machine for 14 h. According to 0.5 mol / L(Co / Ni) 2+ Molarity Dissolve cobalt chloride and nickel chloride in deionized water. According to NaOH:(Co / Ni) 2+ The molar ratio is 98% of the stoichiometric ratio of 2:1 to calculate the amount of NaOH added, and NaOH is dissolved in deionized water at a molar concentration of 4 mol / L. Transfer the filtered NaOH solution into the stirred reaction tank, control the temperature of the reaction tank at 65 °C, and drop the filtered cobalt chloride and nickel chloride mixed solution into the NaOH solution through 3 pipes. Transfer the reaction product cobalt a...

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Abstract

The invention discloses a preparation method of dense coated composite powder and super coarse and extra coarse grained cemented carbide, which is characterized in that: mechanical activated powder mainly comprising WC, and a Co / Ni hydroxide alkaline pulp material are used as raw materials, and by utilizing the self catalytic activity and the heterogeneous nucleation effect of the mechanical activated powder, without adding a sensitizing agent, an activating agent, a catalyst, and other foreign substances, Co / Ni coated WC composite powder with a nano-assembled structure is prepared by a hydrothermal high-pressure hydrogen reduction process; and the thermal diffusion homogenization treatment of the composite powder is carried out in a hydrogen atmosphere by utilizing a nano-diffusion sintering effect to obtain the dense Co / Ni coated WC composite powder, and the composite powder is used as a raw material to prepare the high-quality super coarse and extra coarse-grained cemented carbide.The preparation method has the characteristics of environmental protection, low cost and the like.

Description

technical field [0001] The invention relates to a method for preparing cemented carbide, in particular to a method for preparing ultra-coarse and ultra-coarse-grained cemented carbide by a dense coating composite powder process. Background technique [0002] Cemented carbide is produced by powder metallurgy and consists of transition group refractory metal compounds (WC, TiC, TaC, NbC, etc.) and bonding metals (Co, Ni, Fe, etc.), with a hard phase + bonding Engineering composites with phase structure characteristics. During the sintering process, the cemented carbide forms a liquid phase through eutectic reaction, and the sintering of cemented carbide is a typical liquid phase sintering. The binder phase of cemented carbide is a solid solution of transition metals such as C and W, which is based on the binder metal. [0003] According to the classification standard of cemented carbide of Sandvik, the largest cemented carbide manufacturer in the world, cemented carbides wit...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C29/08C22C1/05B22F1/02
Inventor 张立陈述吴厚平熊湘君
Owner CENT SOUTH UNIV