Ultrafine cemented carbide and preparation method and application thereof

A cemented carbide and Fischer particle size technology, applied in the field of powder metallurgy, can solve the problems of coarse inclusion, affecting the comprehensive performance of ultra-fine cemented carbide, and no specific process conditions for drying.

Active Publication Date: 2010-01-20
JIANGXI RARE EARTH & RARE METALS TUNGSTEN GRP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the above-mentioned patent documents do not limit other properties of WC powder, Co powder and grain growth inhibitor, such as total carbon content, combined carbon content, free carbon content, oxygen content, etc., nor disclose specific drying conditions. ; and the quality of ultra-fine cemented carbide is greatly affected by the production process of each step. If the production process is not properly controlled, it is easy to produce defects such as micropores, polycrystals, cobalt pools, grain growth and clamping in the alloy. Thus affecting the comprehensive performance of ultrafine cemented carbide

Method used

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  • Ultrafine cemented carbide and preparation method and application thereof
  • Ultrafine cemented carbide and preparation method and application thereof
  • Ultrafine cemented carbide and preparation method and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0079] 1) Ingredients:

[0080] 8.0% Co powder, 0.5% TaC powder, the balance of WC powder, of which Cr 3 C 2 The content is 0.5%.

[0081] 2) wet grinding

[0082] Use alcohol as the wet grinding medium, the ball-material ratio is 5:1, the liquid-solid ratio is 350ml / Kg, and the paraffin wax accounting for 2.3% of the raw materials is poured into the ball mill in the form of molten liquid 0.3.hr before the raw materials are added, and the total wet grinding Time: 70 hours;

[0083] 3) spray drying

[0084] After the wet grinding is completed, the slurry obtained is sent to the spray drying tower to obtain the mixture; the process conditions of the spray drying are:

[0085] Solid content of slurry: 70%,

[0086] Nozzle swirl combination: 1.1, 1.2,

[0087] Atomization pressure: 800Kpa,

[0088] Oil heater oil temperature: 200°C,

[0089] Pressure inside the tower: 4.5Kpa,

[0090] Oxygen content in the tower: 2.0%,

[0091] Tower N 2 Air inlet temperature: 150°C, ...

Embodiment 2

[0105] The process parameters of each step are shown in Table 5. Through the same steps as in Example 1, the obtained ultra-fine cemented carbide cutter has a transverse fracture strength of 3200Mpa, a hardness of 92.5HRA, a coercive force of 31KA / m, and a porosity of A02, B00, C00, WC average grain size is 340nm.

Embodiment 3

[0107] The process parameters of each step are shown in Table 5. Through the same steps as in Example 1, the obtained ultra-fine cemented carbide cutter has a transverse fracture strength of 3300Mpa, a hardness of 92.8HRA, a coercive force of 33KA / m, and a porosity of A02, B00, C00, the average grain size of WC is 320nm.

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Abstract

The invention discloses ultrafine cemented carbide which comprises the following components in raw materials in percentage by weight: 8.0-9.0 percent of Co, 0.5-1.0 percent of TaC and the balance of WC including 0.3-2.0 percent of Cr3C2; and the preparation method comprises the steps of blending, wet milling, spray drying, pressure molding and sintering. The invention definitely limits the optimized technical conditions of all the components in the raw materials and the optimized process conditions of all the steps of preparation; the ultrafine cemented carbide has good hardness property and good strength property: the transverse rupture strength is equal to or higher than 2800 MPa, the hardness is equal to or higher than 92.5 HRA, the coercive force is 26-35 KA / m and the average grain size of the WC is 200-400 nm. And the invention also discloses application of the ultrafine cemented carbide in the preparation of cemented carbide tools.

Description

technical field [0001] The invention belongs to the field of powder metallurgy, and in particular relates to a WC-Co ultrafine cemented carbide and its preparation method and application. Background technique [0002] WC-Co cemented carbide is widely used in the fields of mechanical processing, petroleum, mining, mold and structural wear parts due to its high strength, hardness, excellent wear resistance and oxidation resistance. According to the grain size of WC in the alloy, WC-Co cemented carbide is generally divided into ultrafine cemented carbide and nanometer cemented carbide. The cemented carbide grain size classification standard of the ISO / TC190 technical committee defines cemented carbide with a grain size of less than 0.2 μm (200nm) as nano-hard alloy, and the grain size is 0.2 μm (200nm) to 0.5 μm ( 500nm) cemented carbide is defined as ultrafine cemented carbide. Ultra-fine cemented carbide has excellent properties such as high strength, high hardness, and hig...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C29/08C22C1/05B22F3/16
Inventor 李克林
Owner JIANGXI RARE EARTH & RARE METALS TUNGSTEN GRP
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