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Preparation method for high-strength and high-hardness nanocrystalline tungstate-cobalt hard alloy

A cemented carbide, high hardness technology, applied in the field of cemented carbide preparation, can solve the problem of low high temperature hardness and high temperature strength of alloys, increase the difficulty of manufacturing high-quality cemented carbide, and difficult to unify wear resistance and toughness. problems, to achieve the effect of improving the overall performance of the alloy, reducing the defects, and slowing down the irregular growth.

Inactive Publication Date: 2013-03-27
HUNAN CENTURY SPECIAL ALLOY
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0002] With the continuous development of the cemented carbide industry, the requirements for its raw material WC powder (ie tungsten carbide powder) are getting higher and higher, especially the preparation of nano-sized cemented carbide has strict requirements on the particle size of WC powder. At present, The degree of aggregation of WC powder is relatively high, and it is difficult for tungsten carbide powder manufacturers to control the powder particle size to meet the requirements of nanocrystalline cemented carbide manufacturing. The WC powder produced has WC particle aggregates.
Due to the different degree of combination of aggregates, it is more difficult to manufacture high-quality cemented carbide, making it difficult to achieve a high degree of uniformity in wear resistance and toughness of cemented carbide products; and the cost of imported WC powder is very high. Not conducive to large-scale domestic production
Therefore, the grains of tungsten-cobalt cemented carbide produced by wet grinding, drying, pressing molding, vacuum sintering and other processes are generally between 1.2~4.0μm, the bending strength is 2200~3000MPa, and the hardness is HRA86.0~91.0 , the matching of strength and microhardness is poor, the overall performance is low, especially the high-temperature hardness and high-temperature strength of the alloy are not high, the impact resistance and thermal plastic deformation resistance are poor, and it is difficult to work in a high-temperature environment, which greatly restricts the hardness of the alloy. The application range of quality alloy

Method used

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] A method for preparing high-strength, high-hardness nanocrystalline tungsten-cobalt cemented carbide, which includes the following process steps: conventional raw material intensive grinding, batching, wet grinding, drying, mixing forming agents, granulation, compression molding and pressure sintering ;Using sub-fine WC powder with a particle size of 0.6~0.8μm (FSSS) as raw material, 1‰VC and 2.5‰Cr 2 C is an inhibitor. The chemical reagent Tween 80 and the mass ratio of acetone and n-hexane mixture are 1:9 for grinding. The ball milling medium is a mixture of acetone and n-hexane, and the mass ratio is 6:4. , the sub-fine WC powder is jet-grinded, dispersed and classified for 28 hours; the coarse-grained WC particles are removed, and the sieved coarse-grained WC is re-grinded, and the final average particle size is 0.1~0.4μm (FSSS) WC powder with superfine particle size; 0.2~0.4μm (FSSS) ultrafine particle size cobalt powder and 0.1~0.4μm (FSSS) superfine particle size...

Embodiment 2

[0029] A method for preparing high-strength, high-hardness nanocrystalline tungsten-cobalt cemented carbide, which includes the following process steps: conventional raw material intensive grinding, batching, wet grinding, drying, mixing forming agents, granulation, compression molding and pressure sintering ;Using sub-fine WC powder with a particle size of 0.6~0.8μm (FSSS) as raw material, 1.5‰VC and 3.5‰Cr 2 C is an inhibitor. The chemical reagent Tween 80 and the mass ratio of acetone and n-hexane mixture are 1.5:8.5 for grinding. The grinding medium is a mixture of acetone and n-hexane, and the mass ratio is 7:3. , through 36 hours of jet grinding, dispersing and classifying and sieving the sub-fine WC powder; remove the coarse-grained WC particles, and re-grind the sieved coarse-grained WC, and finally select the average particle size of 0.1~0.4μm (FSSS) WC powder with superfine particle size; 0.2~0.4μm (FSSS) ultrafine particle size cobalt powder and 0.1~0.4μm (FSSS) sup...

Embodiment 3

[0032]A method for preparing high-strength, high-hardness nanocrystalline tungsten-cobalt cemented carbide, which includes the following process steps: conventional raw material intensive grinding, batching, wet grinding, drying, mixing forming agents, granulation, compression molding and pressure sintering ;Using sub-fine WC powder with a particle size of 0.6~0.8μm (FSSS) as raw material, 1‰VC and 4.5‰Cr 2 C is an inhibitor. The chemical reagent Tween 80 and the mass ratio of acetone and n-hexane mixture are 1:9. The enhanced grinding process is combined. The ball milling medium is a mixture of acetone and n-hexane, and the mass ratio is 7:3. , the sub-fine WC powder is jet-grinded, dispersed and classified for 42 hours; the coarse-grained WC particles are removed, and the sieved coarse-grained WC is re-grinded, and the final average particle size is 0.1~0.4μm (FSSS) WC powder with superfine particle size; 0.2~0.4μm (FSSS) ultrafine particle size cobalt powder and 0.1~0.4μm (...

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PUM

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Abstract

The invention discloses a preparation method for a high-strength and high-hardness nanocrystalline tungstate-cobalt hard alloy, which is finished by adopting eight process flows of reinforced grinding machining, proportioning, wet-grinding, drying, forming agent doping, granulating, press-forming and pressure-sintering for the conventional raw material, namely, sub-fine WC (tungstate-cobalt) powder; in the method, common sub-fine-grain WC powder having a Fsss (furnace safeguard supervisory system) granularity of 0.6-0.8 mum, and metal Co powder having a granularity of 0.2-0.4 mum; and the granularity and the granularity distribution of the sub-fine WC are changed by the added working procedure of reinforced grinding treatment, so that the advantage granularity of WC in the obtained super-coarse-grain hard alloy achieves 0.2-0.4 mum, and the hard alloy is high in toughness, complete in crystallization, few in defects, small in microstrain, uniform in sub-fine grains, high in microhardness, and greatly improves the wear resistance and impact toughness.

Description

technical field [0001] The invention relates to a preparation method of cemented carbide, in particular to a preparation method of high-strength and high-hardness nanocrystalline tungsten-cobalt cemented carbide. Background technique [0002] With the continuous development of the cemented carbide industry, the requirements for its raw material WC powder (ie tungsten carbide powder) are getting higher and higher, especially the preparation of nano-sized cemented carbide has strict requirements on the particle size of WC powder. At present, The degree of aggregation of WC powder is relatively high, and it is difficult for tungsten carbide powder manufacturers to control the powder particle size to meet the requirements of nanocrystalline cemented carbide manufacturing. The WC powder produced has WC particle aggregates. Due to the different degree of combination of aggregates, it is more difficult to manufacture high-quality cemented carbide, making it difficult to achieve a h...

Claims

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Application Information

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IPC IPC(8): C22C1/05C22C29/08
Inventor 李亚兰肖华
Owner HUNAN CENTURY SPECIAL ALLOY
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