High-temperature sintering process for neodymium iron boron

A high-temperature sintering, neodymium-iron-boron technology, applied in the field of iron-based alloy manufacturing process, can solve the problems of increasing power consumption, prolonging sintering time, increasing production cost, etc., and achieves the effect of accelerating exhaust speed and stable equipment pressure rise rate.

Active Publication Date: 2013-09-25
NINGBO HUAHUI MAGNETIC IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] The high-temperature sintering process of NdFeB in the prior art includes the following steps: the product enters the furnace → low vacuum → high vacuum → staged heating, heat preservation → final gas release point at about 800 ° C → high temperature sintering → tempering → cooling out of the furnace, the whole process The sintering process is controlled by a high vacuum, so there is a staged temperature rise, and the temperature is kept at a low temperature for a long time in order to achieve the basic vacuum degree of high vacuum by using a diffusion pump (secondary pump, which requires a mechanical pump as a backing pump). Neglecting the protective function of hydrogen as a reducing gas in the sintering process of NdFeB products made of hydrogen crushed powder, and the fact that the exhaust speed of NdFeB products manufactured by hydrogen crushed powder increases with the increase of temperature, artificially It limits the exhaust velocity of the product, prolongs the sintering time, increases the consumption of electric energy, and thus increases the production cost

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] The NdFeB high-temperature sintering process provided in this embodiment includes compacting NdFeB powder, and the sintering steps after compacting are as follows:

[0014] 1) Put the NdFeB powder compact into the furnace;

[0015] 2) Vacuuming, using the pump unit of H-150 slide valve vacuum pump and ZTP-1200 Roots pump, opening the rough pumping valve to pump the vacuum in the sintering equipment to 1.0×10-1Pa, while the pressure rise rate of the sintering furnace is stable at 0.02Pa / h;

[0016] 3) Heating up and exhausting, the target temperature is 600°C, after holding for 0.5h, it rises to the final exhausting temperature point of 950°C, and after the exhaust vacuum reaches 1.0×10-1Pa, it continues to heat up to 1080°C, holding for 4h, at this time the pump The group continues to work, maintaining a vacuum of 1.0×10-1Pa;

[0017] 4) Tempering, lower the temperature to 900°C, keep warm for 2h, then cool down to 490°C, keep warm for 4h;

[0018] 5) Turn off the pu...

Embodiment 2

[0021] The NdFeB high-temperature sintering process provided in this example includes compacting NdFeB powder, and the sintering steps after compacting are as follows:

[0022] 1) Put the NdFeB powder compact into the furnace;

[0023] 2) Vacuuming, using the pump unit of H-150 slide valve vacuum pump and ZTP-1200 Roots pump, opening the rough pumping valve to pump the vacuum in the sintering equipment to 1.0×10-1Pa, while the pressure rise rate of the sintering furnace is stable at 0.5Pa;

[0024] 3) Heating up and exhausting, the target temperature is 600°C, after holding for 0.5h, it rises to the final exhausting temperature point of 950°C, and after the exhaust vacuum reaches 1.0×10-1Pa, it continues to heat up to 1080°C, holding for 4h, at this time the pump The group continues to work, maintaining a vacuum of 1.0×10-1Pa;

[0025] 4) Tempering, lower the temperature to 900°C, keep warm for 2h, then cool down to 490°C, keep warm for 4h;

[0026] 5) Turn off the pump uni...

Embodiment 3

[0029] The NdFeB high-temperature sintering process provided in this embodiment includes compacting NdFeB powder, and the sintering steps after compacting are as follows:

[0030] 1) Put the NdFeB powder compact into the furnace;

[0031] 2) Vacuuming, using the pump unit of H-150 slide valve vacuum pump and ZTP-1200 Roots pump, opening the rough pumping valve to pump the vacuum in the sintering equipment to 1.0×10-1Pa, while the pressure rise rate of the sintering furnace is stable at 0.25Pa;

[0032] 3) Heating up and exhausting, the target temperature is 600°C, after holding for 0.5h, it rises to the final exhausting temperature point of 950°C, and after the exhaust vacuum reaches 1.0×10-1Pa, it continues to heat up to 1080°C, holding for 4h, at this time the pump The group continues to work, maintaining a vacuum of 1.0×10-1Pa;

[0033] 4) Tempering, lower the temperature to 900°C, keep warm for 2h, then cool down to 490°C, keep warm for 4h;

[0034] 5) Turn off the pump...

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PUM

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Abstract

The invention discloses a manufacture process of an iron-base alloy and particularly discloses a high-temperature sintering process for neodymium iron boron. The process includes the steps that (1) neodymium iron boron powder is compacted and placed in a furnace; (2) vacuum is pumped, a pump group of a rotary plunger vacuum pump and a roots pump is adopted, and a rough valve is opened to conduct pumping to enable the vacuum degree in a sintering device to be 1.0x10-1Pa; (3) temperature is raised and air is exhausted, the target temperature is 600 DEG C, after the temperature is kept for 0.5h, the temperature is raised to the final air exhaust temperature point of 950 DEG C, after the air exhaustion vacuum degree is 1.0x10-1Pa, the temperature is kept raised to 1080 DEG C, the temperature is kept for 4h, at this time, the pump group keeps working, and the vacuum degree is maintained to be 1.0x10-1Pa; (4) tempering is conducted, the temperature is reduced to 900 DEG C and kept for 2h, and then the temperature is reduced to 490 DEG C and kept for 4h; (5) the pump group is closed, a fan is turned on, and the neodymium iron boron is cooled to the room temperature and taken out from the furnace. The high-temperature sintering process solves the technical problem in the existing high-temperature sintering process for the neodymium iron boron that the sintering time is long and electric energy consumption is large and has the advantages of saving energy consumption and reducing cost and the like.

Description

technical field [0001] The invention relates to a manufacturing process of an iron-based alloy, in particular to a high-temperature sintering process of neodymium-iron-boron. Background technique [0002] The high-temperature sintering process of NdFeB in the prior art includes the following steps: the product enters the furnace → low vacuum → high vacuum → staged heating, heat preservation → final gas release point at about 800 ° C → high temperature sintering → tempering → cooling out of the furnace, the whole process The sintering process is controlled by a high vacuum, so there is a staged temperature rise, and the temperature is kept at a low temperature for a long time in order to achieve the basic vacuum degree of high vacuum by using a diffusion pump (secondary pump, which requires a mechanical pump as a backing pump). Neglecting the protective function of hydrogen as a reducing gas in the sintering process of NdFeB products made of hydrogen crushed powder, and the f...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22F3/16
Inventor 钱辉
Owner NINGBO HUAHUI MAGNETIC IND
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