Method for preparing large-size sintered samarium cobalt permanent magnet

A permanent magnet and large-size technology, applied in the direction of magnetic objects, magnetic materials, inorganic materials, etc., can solve problems such as connection process and strength limitations, low pass rate, degumming, etc., to achieve no abnormal appearance of the magnet, excellent magnetic properties, The effect of simple process

Active Publication Date: 2017-05-31
HUNAN AEROSPACE MAGNET & MAGNETO
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the density uniformity of the large green body pressed in this way is poor, and it is difficult to take the green body. After sintering, the size of the green body is greatly deformed, and there are internal cracks, and the qualified rate is very low.
A method for preparing a large-size bonded permanent magnet disclosed in CN104361989A, but because it has a huge difference with the sintered permanent magnet in the formulation components and preparation process, it is not comparable and referential
However, this method will be limited in terms of connection process and strength. The glue will age with time, which will affect the service life of the magnet assembly workpiece, and the working temperature should generally not exceed 200 ° C, otherwise it will be degummed
CN106158200A discloses a method for manufactur

Method used

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  • Method for preparing large-size sintered samarium cobalt permanent magnet
  • Method for preparing large-size sintered samarium cobalt permanent magnet
  • Method for preparing large-size sintered samarium cobalt permanent magnet

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0048] Reference example 1

[0049] The preparation method of samarium cobalt alloy ingot: According to weight parts, 25.5 parts of Sm, 52 parts of Co, 12.5 parts of Fe, 7 parts of Cu and 3 parts of Zr are placed in a vacuum intermediate frequency induction furnace and evacuated to a vacuum of 0.08Pa. Then fill the furnace with argon until the pressure in the furnace is -0.05MPa, smelt at 1500°C for 15min, then at 1440°C, heat preservation and refining for 5min, and finally pour it into a condensing mold for rapid cold casting and serve.

Example Embodiment

[0050] Example 1

[0051] (1) The samarium-cobalt alloy ingot obtained in Reference Example 1 was roughly crushed into coarse particles with an average particle diameter of 300μm using a jaw crusher and a medium crusher, and then powdered into a jet mill magnetic powder with an average particle size of 3.8μm by jet mill. Add 120# aviation gasoline equivalent to 3% of its mass into the magnetic powder and mix it with a double cone mixer for 1 hour to obtain the magnetic powder;

[0052] (2) Two 1530g magnetic powders after mixing in step (1) were oriented and pressed in a 1.6T magnetic field at a pressure of 4MPa, and the size specification was 110 (front and back direction) × 65 (pressing direction) × 58 (Magnetization direction) mm, density is 3.69g / cm 3 The shrinkage rate of a single green body in the pressing direction is designed to be 1.313, that is, 65 (the size of the green body in the pressing direction) × 2 / 99 (the size of the blank in the pressing direction) = 1.313, and t...

Example Embodiment

[0056] Example 2

[0057] (1) Same as step (1) of Example 1;

[0058] (2) Two parts of 1640g of the magnetic powder mixed in step (1) were oriented and pressed in a 2.0T magnetic field at a pressure of 6MPa, and the size specification was 115 (front and back direction) × 66 (pressing direction) × 60 (Magnetization direction) mm, density is 3.60g / cm 3 For the green body, the shrinkage rate of a single green body in the pressing direction is designed to be 1.320, that is 66 (the size of the green body in the pressing direction) / 50 (the size of the blank in the pressing direction) = 1.320, the shrinkage rate in the front and back direction is 1.349, and the shrinkage rate in the magnetization direction The corresponding value is 1.282, and two identical green bodies are obtained;

[0059] (3) The two green bodies obtained in step (2) are arranged in a front-to-back direction, and the magnetization direction between the two bodies is arranged crosswise, and the upper indenter between the...

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Abstract

A method for preparing a large-size sintered samarium cobalt permanent magnet includes the following steps that firstly, a samarium cobalt alloy ingot is smashed, milled and mixed to obtain magnetic powder; secondly, oriented-pressing and forming are conducted in a magnetic field to obtain blanks; thirdly, two or more blanks are spliced together and tightly wrapped by fresh-keeping films, vacuum packaging is conducted, cold isostatic pressing is conducted, and a formed blank is obtained; fourthly, the formed blank is subjected to vacuum pre-sintering, inert gas is introduced for sintering, solid solution is conducted, air cooling is conducted to normal temperature, and a sintered blank is obtained; fifthly, the sintered blank is subjected to aging treatment, cooling and heat preservation are conducted, air cooling is conducted to normal temperature, and the large-size sintered samarium cobalt permanent magnet is obtained through machining. The ultra-large sintered samarium cobalt permanent magnet with the unilateral size larger than 130 mm can be prepared through the method, is good in magnetic property, and can reach the XGS30H trademark magnet standard, the product yield reaches 94% or above, the magnetic property is not changed after temperature-resistant and fatigue testing, and the appearance is normal. The process is simple, large-scale production can be achieved, and the cost is low.

Description

technical field [0001] The invention relates to a method for preparing a permanent magnet, in particular to a method for preparing a large-scale sintered samarium-cobalt permanent magnet. Background technique [0002] Sintered samarium cobalt permanent magnet material is a new type of functional material developed since the 1960s. It has high magnetic energy product, high coercive force, extremely low temperature coefficient, high temperature resistance (above 350 ° C), corrosion resistance, oxidation resistance, etc. With excellent characteristics, it is widely used in motors, instruments, sensors, detectors, engines, radars and other high-tech and military fields. The method of preparing samarium-cobalt permanent magnet materials in industrial production is mainly powder metallurgy. The general production process is: batching → smelting → powder making → molding → sintering → tempering → magnetic detection → post-processing → surface treatment → inspection → finished produ...

Claims

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Application Information

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IPC IPC(8): H01F1/057H01F1/08B22F3/02B22F3/04B22F3/10
CPCB22F3/02B22F3/04B22F3/101H01F1/0551H01F1/0556H01F1/0557
Inventor 王涛谭春林罗明
Owner HUNAN AEROSPACE MAGNET & MAGNETO
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