Method for preparing ultra-coarse grain cemented carbide by flexible ball milling technology

A cemented carbide and ball milling technology, applied in the field of ultra-coarse-grained cemented carbide prepared by flexible ball milling technology, can solve the problems of long process, complicated process, and high production cost, and achieve the effect of short process, simple process and low production cost

Active Publication Date: 2012-08-15
XIAMEN GOLDEN EGRET SPECIAL ALLOY +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In summary, the preparation methods of ultra-coarse-grained cemented carbide reported at home and abroad all require more complicated pretreatment of the po

Method used

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  • Method for preparing ultra-coarse grain cemented carbide by flexible ball milling technology
  • Method for preparing ultra-coarse grain cemented carbide by flexible ball milling technology
  • Method for preparing ultra-coarse grain cemented carbide by flexible ball milling technology

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Ultra-coarse-grained cemented carbide composition WC-6Co, WC raw material Fisher grain size 20.1μm. First pre-mix the WC powder and Co powder in a double-cone or Y-shaped mixer, the pre-mixing time is 0.5h, and the mixer speed is 12rpm; then put the pre-mixed powder into the ball mill for a short period of light ball milling. Add alcohol and paraffin, the material of the grinding ball is WC-Co cemented carbide, its diameter is φ6~φ10mm, the ball milling time is 10h, the ratio of ball to material is 2.5:1, and the speed of the ball mill is 35% of the critical speed; then discharge the slurry in the ball mill , using spray drying to prepare the mixture, followed by pressing and sintering at a temperature of 1480 ° C to obtain an ultra-coarse grained cemented carbide.

[0024] Results: The average grain size of the coarse-grained cemented carbide is 7.0 μm, the hardness is HV30 1140, the porosity is A00B00, image 3 Photographs for metallography.

Embodiment 2

[0026] Ultra-coarse-grained cemented carbide composition WC-10Co, WC raw material Fisher grain size 20.2μm. First pre-mix WC powder and Co powder in a double-cone or Y-shaped mixer, the pre-mixing time is 1.5h, and the mixer speed is 8rpm; then put the pre-mixed powder into a ball mill for a short period of light ball milling. Add alcohol and paraffin, the material of the grinding ball is WC-Co cemented carbide, its diameter is φ6~φ10mm, the ball milling time is 18h, the ratio of ball to material is 2.2:1, and the speed of the ball mill is 50% of the critical speed; then discharge the slurry in the ball mill , using spray drying to prepare the mixture, followed by compression molding, and sintering at a temperature of 1450 ° C to obtain an ultra-coarse-grained cemented carbide.

[0027] Results: The average grain size of ultra-coarse-grained cemented carbide is 9.0 μm, the hardness is HV30 1000, the porosity is A02B00, Figure 4 Photographs for metallography.

Embodiment 3

[0029] Ultra-coarse-grained cemented carbide composition WC-17.5Co, WC raw material Fisher grain size 21.4μm. First pre-mix WC powder and Co powder in a double-cone or Y-shaped mixer. The pre-mixing time is 2 hours, and the mixer speed is 6 rpm; Add alcohol and PEG, the material of the grinding ball is WC-Co cemented carbide, its diameter is φ6~φ10mm, the ball milling time is 14h, the ball-to-material ratio is 2.5:1, and the speed of the ball mill is 20% of the critical speed; then discharge the slurry in the ball mill, The mixture is prepared by spray drying, followed by pressing and sintering at a temperature of 1390°C to obtain an ultra-coarse-grained cemented carbide.

[0030] Results: The average grain size of ultra-coarse-grained cemented carbide is 10.0 μm, the hardness is HV30 770, the porosity is A00B00, Figure 5 Photographs for metallography.

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Abstract

The invention discloses a method for preparing ultra-coarse grain cemented carbide by flexible ball milling technology, which comprises the following steps: firstly premixing ultra-coarse WC powder and Co powder for 0.5-2 h with a rotating speed of 6-12 rpm, wherein the Fisher particle size of the WC powder is 18.0-22.0 microns; performing mild ball milling of the premixed powder, adding liquid grinding mediums and a forming agent, wherein the grinding ball material is WC-Co cemented carbide with a diameter of 6-10 mm, the ball milling time is 8-24 h, the ball-to-powder ratio is 1.5-3.0:1, the rotating speed is 20-55% of a critical rotating speed; then discharging the slurry in the ball mill, preparing a mixture by spray drying, performing pressing and molding, sintering at a temperature of 1390-1500 DEG C, wherein the prepared ultra-coarse grain cemented carbide has a grain size of 6.0-10.0 microns, a hardness HV 30 of 740-1240, and a porosity of less than A04B00. The invention is simple in process, short in flow, low in production cost, and suitable for industrial production.

Description

technical field [0001] The invention relates to a method for preparing ultra-coarse-grained hard alloy by flexible ball milling technology. Background technique [0002] In the traditional cemented carbide mixture production process, in order to ensure that the WC / Co powder is mixed evenly during the ball milling process, and at the same time, avoid harmful pores in the alloy during the sintering process, high-strength, long-time ball milling is usually used. However, this process will destroy the secondary particles and primary particles of WC, resulting in a rapid decrease in the particle size of WC during the ball milling process, making it difficult to prepare ultra-coarse-grained cemented carbide with a grain size greater than 6 μm. [0003] U.S. Patent Nos. 5,505,902 and 5,529,804 disclose the method for preparing ultra-coarse-grained cemented carbide, which is to disperse and classify the coarse-grained WC powder by jet grinding, remove fine WC particles, and only sel...

Claims

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Application Information

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IPC IPC(8): C22C1/05C22C29/08
Inventor 吴冲浒吴其山孙东平杨跃杜伟王明胜
Owner XIAMEN GOLDEN EGRET SPECIAL ALLOY
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