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A degreasing method for powder metallurgy sintering

A technology of powder metallurgy and vacuum sintering furnace, applied in the field of powder metallurgy, which can solve the problems affecting the carbon content of materials, insufficient gas condensation, and pollution of vacuum equipment, etc., and achieve the effects of improving material performance, reducing maintenance frequency, and improving cleanliness

Active Publication Date: 2022-04-26
FUJIAN CHANGJIANG GOLDEN DRAGON RARE EARTH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The above method has the following problems: (1) Because the air pressure is relatively low, some lipids are not discharged in time, and are carbonized in a vacuum furnace, which affects the carbon content of the material at high temperature; (2) In the existing cooling well structure, the gas Insufficient condensation, residual lipids will enter the exhaust pipe and vacuum equipment, causing grease to accumulate in the pipeline and pollute the vacuum equipment, affecting the use of equipment

Method used

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  • A degreasing method for powder metallurgy sintering
  • A degreasing method for powder metallurgy sintering
  • A degreasing method for powder metallurgy sintering

Examples

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Effect test

Embodiment 1

[0032] Using the above degreasing method, the NdFeB sintered blank (35SH (Nd 27.02wt%, Dy 0.24wt%, Ho 4.74wt%, Fe 64.93wt%, Co 1wt%, Nb 0.2wt%, Cu 0.15wt%, Al0.75wt%, Ga 0.2wt%, B0.96wt%), the fat content added is 0.5wt%) put into the heating area of ​​the vacuum sintering furnace, in the degreasing stage, the furnace is evacuated to the furnace When the internal vacuum degree is lower than 1Pa, pump the vacuum while feeding argon gas to keep the air pressure in the furnace at the pressure in the table below, and start heating at the same time to raise the temperature in the furnace to 200°C and keep it warm for 60 minutes, then raise it to 350°C and keep it warm After 60 minutes, the lipid-containing gas passes through the spiral condensation well 3 and the temperature drops to less than 100°C, and the lipid and gas are fully separated.

Embodiment 2

[0042] With reference to the degreasing method of Example 1, NdFeB sintered blanks with different lipid additive contents (35SH (Nd 27.02wt%, Dy 0.24wt%, Ho 4.74wt%, Fe 64.93wt%, Co 1wt%, Nb0.2wt%, Cu0.15wt%, Al 0.75wt%, Ga 0.2wt%, B0.96wt%) are placed in the heating zone of the vacuum sintering furnace, and in the degreasing stage, the furnace is evacuated to the furnace When the internal vacuum degree is lower than 1Pa, pump the vacuum while feeding argon gas to keep the pressure in the furnace at 180Pa, and start heating at the same time to raise the temperature in the furnace to 200°C and keep it for 60 minutes, then rise to 350°C and keep it for 60 minutes. The lipid-containing gas passes through the spiral condensation well and the temperature drops to less than 100°C, and the lipid and gas are fully separated.

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Abstract

The invention discloses a degreasing method for powder metallurgy sintering. The sintered blank is put into the heating area of ​​a vacuum sintering furnace, and when the vacuum is evacuated in the furnace until the vacuum degree is lower than 1Pa, the inert gas is introduced while the vacuum is evacuated, so that the furnace The air pressure in the furnace is maintained between 150-200Pa. At the same time, the heating is started to raise the temperature in the furnace to 200-800°C to vaporize the lipid additives of the sintered blank. The gasified lipid is driven by the inert gas to flow to the spiral condensation well, along the The cooling spiral air channel advances in a spiral manner and is cooled to less than 100°C, and the lipids are condensed and recovered. Through the method of the present invention, the grease condensed on the vacuum furnace wall is greatly reduced, the carbon content in the material is reduced, and the material performance is improved; the grease-containing gas passes through the spiral condensation well to fully separate the grease from the gas, the cleanliness is improved, and the vacuum is protected Equipment, reduce the maintenance frequency of equipment, improve the service life of equipment, and reduce environmental pollution.

Description

technical field [0001] The invention relates to the technical field of powder metallurgy, in particular to a degreasing method for powder metallurgy sintering. Background technique [0002] In most powder metallurgy materials, the carbon content has a great influence on the performance of the material. The carbon content in the material is brought in by the impurities of the material itself and the additives. The most important thing is the additives. These additives may be Molding agent, lubricant, release agent, etc. In the manufacturing process, usually in the process of vacuum sintering in a vacuum sintering furnace, there will be a process dedicated to degreasing the material. Specifically, the furnace is evacuated by a vacuum pump group, and the temperature is raised according to the preset degreasing temperature curve. As the temperature rises, the additives are gradually vaporized and pumped out by the vacuum pump unit. The detached fat passes through a "<" baffl...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B22F3/10
CPCB22F3/1021B22F3/1007B22F2998/10B22F2201/10
Inventor 王清江吴建鹏骆溁廖宗博范宜荣
Owner FUJIAN CHANGJIANG GOLDEN DRAGON RARE EARTH CO LTD