A kind of nanocrystalline cemented carbide and preparation method thereof

A cemented carbide and nanocrystalline technology, which is applied in the field of nanocrystalline cemented carbide for railway line maintenance and screen cleaning locomotives and its preparation, can solve the problems of increased Rockwell hardness and decreased toughness of cemented carbide, and achieves high impact toughness, The effect of eliminating shrinkage stress, high hardness and high strength

Active Publication Date: 2016-02-03
CHINA SHENHUA ENERGY CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The purpose of the present invention is to overcome the disadvantages of hard alloys in the prior art that the toughness decreases while the Rockwell hardness is increased, and to provide a nanocrystalline hard alloy for railway line maintenance and screen cleaning locomotives and a preparation method thereof

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  • A kind of nanocrystalline cemented carbide and preparation method thereof
  • A kind of nanocrystalline cemented carbide and preparation method thereof
  • A kind of nanocrystalline cemented carbide and preparation method thereof

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preparation example Construction

[0021] According to the present invention, a preparation method of nanocrystalline cemented carbide is also provided, wherein the preparation method comprises the following steps:

[0022] (1) The mixed particles of coarse-grained tungsten carbide, nano-grained tungsten carbide and cobalt powder are subjected to mechanical compression molding;

[0023] (2) sintering the mixed particles formed in step (1) under pressure of an inert gas;

[0024] (3) After the sintering treatment in step (2), the secondary sintering treatment is performed;

[0025] Wherein, the amount of coarse-grained tungsten carbide, nano-grained tungsten carbide and cobalt powder is such that the prepared nanocrystalline cemented carbide can contain 55-75% by weight of coarse-grained tungsten carbide and 15-25% by weight of nanoparticles Tungsten carbide and cobalt powder may contain 10-20% by weight.

[0026] According to the present invention, the amount of the coarse-grained tungsten carbide, the nano-g...

Embodiment 1

[0038] Step (1): The mixed particles of coarse-grained tungsten carbide with a grain size of 12 μm, nano-particle tungsten carbide with a grain size of 0.64 μm and cobalt powder with a grain size of 0.3 μm were prepared at a pressure of 1200 kg / cm 2 Under mechanical pressure forming treatment;

[0039] Step (2): The mixed particles formed in step (1) are sintered under the inert gas nitrogen, under the pressure of the inert gas pressure of 4.7MPa, the sintering temperature is 1435°C, and the sintering time is 115 minutes. ;

[0040] Step (3): after the sintering treatment in step (2), sintering treatment at a temperature of 1395 ° C for 50 minutes;

[0041] Wherein, the amount of coarse-grained tungsten carbide, nano-grained tungsten carbide and cobalt powder is such that the prepared nanocrystalline cemented carbide contains 60 wt % of coarse-grained tungsten carbide, 23 wt. % of nano-grained tungsten carbide and 17 wt. % cobalt powder.

[0042] figure 1It is a metallogra...

Embodiment 2

[0046] Step (1): The mixed particles of coarse-grained tungsten carbide with a grain size of 14 μm, nano-particle tungsten carbide with a grain size of 0.68 μm and cobalt powder with a grain size of 0.8 μm were prepared at a pressure of 1800 kg / cm 2 Under mechanical pressure forming treatment;

[0047] Step (2): The mixed particles formed in step (1) are sintered under the inert gas nitrogen, under the pressure of the inert gas pressure of 4.5 MPa, the sintering temperature is 1445 ° C, and the sintering time is 125 minutes. ;

[0048] Step (3): after the sintering treatment in step (2), sintering treatment at a temperature of 1405 ° C for 70 minutes;

[0049] Wherein, the amount of coarse-grained tungsten carbide, nano-grained tungsten carbide and cobalt powder is such that the prepared nanocrystalline cemented carbide contains 70 wt % of coarse-grained tungsten carbide, 18 wt. % of nano-grained tungsten carbide and 12 wt. % cobalt powder.

[0050] The average particle siz...

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Abstract

The invention discloses a nanocrystalline hard alloy and a preparation method thereof. The nanocrystalline hard alloy contains coarse-particle tungsten carbide, nano-particle tungsten carbide and cobalt powder, wherein by adopting the total weight of the nanocrystalline hard alloy as a benchmark, the content of the coarse-particle tungsten carbide is 55 to 75 percent, the content of the nano-particle tungsten carbide is 15 to 25 percent, and the content of the cobalt powder is 10 to 20 percent. The preparation method comprises the steps of mechanically pressurizing and molding the coarse-particle tungsten carbide, the nano-particle tungsten carbide and the cobalt powder, sintering the mixture, and carrying out secondary sintering on the mixture to finally obtain the nanocrystalline hard alloy. The internal structure of the nanocrystalline hard alloy is adequately compact, and the retraction stress inside the nanocrystalline hard alloy can be eliminated.

Description

technical field [0001] The invention relates to a nanocrystalline cemented carbide and a preparation method thereof, in particular to a nanocrystalline cemented carbide for railway line maintenance and screen cleaning locomotives and a preparation method thereof. Background technique [0002] The L1469 type plate for railway line maintenance and screen cleaning vehicle is the main part and vulnerable part used in the process of railway line cleaning. The L1469 type plate for the railway line maintenance screen cleaning vehicle belongs to the field of alloy wear-resistant plates. According to the technical principle and requirements of the alloy wear-resistant plate, the inventor of the present invention determines that the L1469 type plate for the railway line maintenance screen cleaning vehicle mainly includes wear-resistant plates. Plate base material, nanocrystalline cemented carbide and welding process. [0003] At present, among the L1469 type plates used in domestic r...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C29/08C22C1/05
Inventor 王军林生福宫实俊刘学敏李红利孙静涵李贵友李振峰
Owner CHINA SHENHUA ENERGY CO LTD
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