Method for preparing WC-Co hard alloy by rapid sintering under multi-physics coupling action

A rapid sintering, multi-physics technology, applied in the field of rapid sintering to prepare tungsten carbide-cobalt (WC-Co) cemented carbide, can solve the problems of complex process, environmental pollution, long preparation cycle, etc., to simplify the process flow, improve the Product quality, effect of shortening sintering time

Inactive Publication Date: 2013-03-27
SICHUAN UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to address the existing problems and deficiencies in the preparation of WC-Co cemented carbide, such as complicated procedures, long preparation cycle, high molding temperature, low product qualification rate, and the dependence of raw materials on additives, resulting in low product purity. It causes certain pollution to the environment, and defects such as grain growth in the sintering process, and provides a method for preparing WC-Co cemented carbide by rapid sintering under the coupling of multiple physical fields.

Method used

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  • Method for preparing WC-Co hard alloy by rapid sintering under multi-physics coupling action

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] The mass of the powder is calculated according to the size of the cemented carbide tool (the side length of the triangle is 3.26mm and the thickness is 2.4mm) and the theoretical density of the corresponding powder. Mix the powder with a weight ratio of WC:Co=94:6, weigh it evenly, put it into the mold and fix it with a chuck, and control the heating rate at 30°C / s under the vacuum condition of ≤0.01Pa. The end loading force is 100Mpa. When the temperature reaches 950°C, it is lowered to 400°C at a cooling rate of 50°C / s, and then heated to 950°C at a heating rate of 50°C / s, and the cycle is repeated for 5 times. Just take out the parts. The relative density of the parts obtained is 89.52%, the Rockwell hardness is 90.1HRA, and the coercive force is 35.43KA / m.

Embodiment 2

[0029] The mass of the powder is calculated according to the size of the cemented carbide tool (the side length of the triangle is 3.26mm and the thickness is 2.4mm) and the theoretical density of the corresponding powder. Mix the powder with a weight ratio of WC:Co=92:8, weigh it evenly, put it into the mold and fix it with a chuck, and control the heating rate at 30°C / s under the vacuum condition of ≤0.01Pa. The end loading force is 100MPa. When the temperature reaches 950°C, it drops to 400°C at a cooling rate of 50°C / s, and then reheats to 950°C at a heating rate of 50°C / s. The cycle is 5 times, and the powder is formed in the mold and completed. Dense, and finally turn off the power and air-cool and take out the parts. The relative density of the parts obtained is 95.28%, the Rockwell hardness is 92.2HRA, and the coercive force is 32.24KA / m.

Embodiment 3

[0031]The mass of the powder is calculated according to the size of the cemented carbide tool (the side length of the triangle is 3.26mm and the thickness is 2.4mm) and the theoretical density of the corresponding powder. Mix the powder with a weight ratio of WC:Co=90:10, weigh it evenly, put it into the mold and fix it with a chuck, and control the heating rate at 30°C / s under the vacuum condition of ≤0.01Pa. The end loading force is 100MPa. When the temperature reaches 950°C, it is lowered to 400°C at a cooling rate of 50°C / s, and then heated to 950°C at a heating rate of 50°C / s. The cycle is 5 times, and the powder is formed in the mold and completed. Dense, and finally turn off the power and air-cool and take out the parts. The relative density of the parts obtained is 99.89%, the Rockwell hardness is 93.1HRA, and the coercive force is 30.52KA / m.

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Abstract

The invention discloses a method for preparing WC-Co hard alloy by rapid sintering under a multi-physics coupling action, which is characterized by comprising the steps of: evenly mixing powder of WC and Co, wherein the weight ratio of WC to Co is 84-94: 16-6; weighing and then filling into a mould; then, under the conditions that the heating speed is 15-100 DEG C/ s and the vacuum degree is less than or equal to 0.01Pa, electrifying the mould containing the WC-Co powder with alternating current for rapid heating, and applying 10-200MPa acting force to the two ends of the mould; under the continuous action of electric field and force field, carrying out instant electric heating impact for different times when temperature rises to 800-1000 DEG C; and finally, cutting off the power, cooling with air and taking out the product. The electric heating impact comprises the following steps: cooling from the sintering temperature to 400 DEG C at the cooling speed of 15-100 DEG C/ s and then heating to the sintering temperature at the heating speed of 15-100 DEG C/ s; wherein the circulation time(s) is/ are 1-10 time(s). The method simplifies the technological process, is rapid, efficient, energy-saving and environment-friendly, improves the quality of the hard alloy and is capable of replacing the existing preparation method of the hard alloy.

Description

technical field [0001] The invention relates to a method for preparing tungsten carbide-cobalt (WC-Co) hard alloy by rapid sintering under the coupling action of multiple physical fields, and belongs to the technical field of hard alloy prepared by rapid sintering. Background technique [0002] Cemented carbide has high hardness and red hardness, high elastic modulus, and high wear resistance. It is currently the most important cutting tool material and is known as "the tooth of industry". At present, the international and domestic preparation of cemented carbide is mainly produced through the traditional powder metallurgy process. The production process is: powder preparation→powder pretreatment→powder prepress molding→sintering→post-treatment. Since additives such as rubber or paraffin are added to the powder system, in order to remove impurities during the sintering process, an intermediate heat preservation and pre-firing for 1 to 2 hours is required; at the same time, ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C29/08C22C1/04
Inventor 杨屹杨刚秦义黄坤兰尹德强
Owner SICHUAN UNIV
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