A device and method for preparing highly oriented samarium cobalt permanent magnets

Abstract

The invention discloses a device for preparing a highly oriented samarium cobalt permanent magnet, belongs to the technical field of permanent magnet material preparation, and comprises a power system, a magnetic field system, and a molding system, wherein the molding system comprises a mold, an upper transmission shaft and a lower transmission shaft, the mold is hollow, the axial length of the mold is lengthened by 2-3 times, the gaps between the mold and the upper transmission shaft and the lower transmission shaft are both 0.01-0.02 mm, and an opening is further provided on the mold. Also disclosed is a method for preparing a highly oriented samarium cobalt permanent magnet by using the device, during the molding process, the upper transmission shaft is not separated from the mold, and the blank is loaded and taken out through the opening, the upper transmission shaft, the lower transmission shaft and the mold are not completely separated during the entire molding process, and the situation of mutual collision, edge collapse and injury to people is avoided, and the gap between the transmission shaft and the mold is reduced, thereby greatly improving the orientation of the samarium cobalt permanent magnet.

Description

Technical Field

[0001] The invention relates to the technical field of permanent magnetic material preparation, and in particular to a device and method for preparing a highly oriented samarium cobalt permanent magnet. Background Art

[0002] Aerospace thrusters, motors, etc. require highly oriented samarium cobalt permanent magnets, which need an orientation degree of less than 0.2°.

[0003] The traditional powder metallurgy method for preparing samarium cobalt permanent magnets includes smelting, powder making, molding, sintering, heat treatment, and processing steps, all of which are well known to those skilled in the art. The molding equipment press of the molding process includes a mold (also called a cavity), an upper transmission shaft and a lower transmission shaft. The axial length of the mold is relatively short, generally <200 mm. During molding, the relative position of the mold must be adjusted first, and the relative position of the lower end of the upper transmission shaft and the mold must be repeatedly adjusted. However, no matter how the adjustment is made, the fit of the mold is not very ideal, and the molded blank will have a certain dimensional accuracy gap, and the mold is easily damaged. The upper transmission shaft leaves the mold (cavity), and a certain amount of powder produced by the powder making process is loaded into the assembled plate mold (cavity). There is no contact between the upper transmission shaft and the mold. The upper transmission shaft is pressed downward and enters the mold. At the same time, the lower transmission shaft is pressed upward to reach a certain stroke and holding time. The upper transmission shaft returns to its original position upward, and the lower transmission shaft pushes the magnet blank upward to complete a molding operation.

[0004] In the above-mentioned traditional molding method, during the molding process, since the upper transmission shaft and the mold will separate, a gap of 0.05mm-0.5mm needs to be left between the outer dimension of the upper transmission shaft and the inner dimension of the mold, otherwise the upper transmission shaft and the mold are prone to collision, and due to the high pressure of the press, the collision is very likely to cause edge collapse, which in turn causes the collapsed edge to fly up and injure people; in addition, since the gap between the upper transmission shaft and the mold is too large, it is not conducive to the preparation of permanent magnets with high orientation. The orientation degree of the permanent magnets obtained by this traditional molding method is generally between 1° and 5°. Summary of the invention

[0005] One of the purposes of the present invention is to provide a device for preparing highly oriented samarium cobalt permanent magnets to solve the above problems.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: a device for preparing highly oriented samarium cobalt permanent magnets, comprising a power system, a magnetic field system, and a molding system, wherein the molding system comprises a mold and an upper transmission shaft and a lower transmission shaft inserted from the upper and lower ends of the mold respectively, the mold is hollow, the axial length of the mold is lengthened, the axial length of the mold is lengthened by 2-3 times, the gap between the mold and the upper transmission shaft is 0.01-0.02mm, the gap between the mold and the lower transmission shaft is also 0.01-0.02mm, and an opening is provided on the mold.

[0007] The present invention improves the molding device of samarium cobalt permanent magnets: on the one hand, the axial length of the mold is lengthened, and on the other hand, the gap between the mold and the upper and lower transmission shafts is reduced, and openings for filling materials and taking out blanks are provided on the mold, so that during the molding process, the upper transmission shaft can be kept separated inside the mold, thus avoiding the edge collapse and injury caused by the collision between the upper transmission shaft and the mold, and at the same time, the obtained permanent magnet has a high orientation degree within 0.2°. The orientation degree of the permanent magnet obtained by the traditional molding method is generally 1°-5°.

[0008] The device of the present invention is particularly suitable for pressing highly oriented rectangular block magnets.

[0009] As a preferred technical solution, there are two openings, which are symmetrically arranged on the front and rear sides of the mold, so that it is convenient to load materials and take out the formed blanks.

[0010] As a preferred technical solution, a linkage rod is also provided at the opening of the rear side of the mold. After the lower transmission shaft sets the formed blank out, the linkage rod is used to push the blank out from the front opening from the rear opening, making it more convenient to take the blank.

[0011] The second object of the present invention is to provide a method for preparing highly oriented samarium cobalt permanent magnets using the above-mentioned device, and the technical scheme adopted is: including batching, smelting, powder making, molding, sintering, heat treatment, and processing steps, characterized in that in the molding process, the device of any one of claims 1-3 is used, and during the entire molding process, the upper transmission shaft and the lower transmission shaft are kept in the mold cavity.

[0012] As a preferred technical solution: during the forming process, the blank is loaded and taken out from the opening.

[0013] Compared with the prior art, the advantages of the present invention are that the upper transmission shaft, the lower transmission shaft and the mold are not completely separated during the entire molding process, thereby avoiding collision and edge breakage and injury to people, and the gap between the transmission shaft and the mold is reduced, greatly improving the orientation of the samarium cobalt permanent magnet. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the whole device for preparing permanent magnets of the present invention;

[0015] Figure 2 It is a structural schematic diagram of the upper transmission shaft of the present invention;

[0016] Figure 3 It is a schematic diagram of the assembly structure of the molding device of the present invention.

[0017] In the figure: A, transmission system; B, magnetic field system; C, molding system; D, molding area; 1, mold; 2, upper transmission shaft; 3, lower transmission shaft; 4, rear opening; 5, front opening. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with the accompanying drawings.

[0019] Example:

[0020] See also Figure 1 , a device for preparing highly oriented samarium cobalt permanent magnets, comprising a power system, a magnetic field system B, and a molding system C,

[0021] The molding system includes a mold 1 and a transmission system A, wherein the transmission system A includes an upper transmission shaft 2 and a lower transmission shaft 3, the upper transmission shaft 2 and the lower transmission shaft 3 are inserted from the upper and lower ends of the mold 1 respectively, and the upper transmission shaft 2 and the lower transmission shaft 3 have the same structure, as shown in FIG. Figure 2 As shown, its longitudinal section is in a "T" shape, the ends of the upper and lower transmission shafts with smaller areas are located outside the mold 1 for connecting to the power system, and the ends with larger areas are located inside the mold 1 for applying pressure to the blank during molding;

[0022] Mold 1 and assembly drawing see Figure 3 , is a hollow rectangular parallelepiped, the axial length of the mold 1 is lengthened, and the front and back sides of the mold 1 are symmetrically provided with a front opening 5 and a rear opening 4, respectively, the front opening 5 and the rear opening 4 are connected with the wall of the mold 1, and the left and right outer walls of the mold 1 are smooth planes, and the smooth plane is not easy to tear the mold and cause the blank to be irregular, the gap between the mold 1 and the upper transmission shaft 2 is 0.01-0.02mm, and the gap between the mold 1 and the lower transmission shaft 3 is also 0.01-0.02mm; the front opening 5 and the rear opening 4 are used for loading and removing the blank after molding, so that the upper transmission shaft 4 does not need to be pulled out and separated from the upper end of the mold when loading and removing the blank;

[0023] Preferably, a linkage rod (not shown in the figure) is provided at the rear opening 4 , so that after the molding is completed, when the lower transmission shaft 3 pushes the magnet blank out, the linkage rod pushes the magnet blank forward from the rear opening 4 out of the front opening 5 .

[0024] In this embodiment, the preparation of a block of samarium cobalt permanent magnets with a length of 50 mm, a width of 50 mm, and a height of 30 mm is taken as an example. The lower edge of the front opening 5 is at least 30.05 mm away from the bottom edge of the mold, and the overall height of the mold, that is, the axial length, is 300 mm. To prepare permanent magnets of the aforementioned size, the axial length of the mold of a conventional device is generally less than 100 mm. The size of the front opening 5 set in the device of this embodiment is 50 mm, the gap between the mold 1 and the upper transmission shaft 2 is 0.015 mm, and the gap between the mold 1 and the lower transmission shaft 3 is also 0.015 mm.

[0025] During the entire molding process, the lower transmission shaft 3 and the upper transmission shaft 2 are both in the cavity of the mold 1. When the molding starts, the upper transmission shaft 2 and the lower transmission shaft 3 move relative to each other, and pressure is applied to the blank between the lower edge and the bottom edge of the mold 1. Figure 3 The forming process is completed by forming the blank in the forming area D in the mold. After the forming is completed, the upper transmission shaft 2 returns to its original position (remains in the mold 1), and the lower transmission shaft 3 moves upward to push the blank until the lower edge of the blank coincides with the lower edge of the front opening 5, and the blank is taken out. The orientation degree of the obtained block samarium cobalt permanent magnet is 0.1°.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for preparing highly oriented samarium cobalt permanent magnets, comprising a power system, a magnetic field system, and a molding system, wherein: The molding system includes a mold and an upper transmission shaft and a lower transmission shaft inserted from the upper and lower ends of the mold respectively, and is characterized in that: the mold is hollow, the axial length of the mold is 300 mm, the gap between the mold and the upper transmission shaft is 0.015 mm, the gap between the mold and the lower transmission shaft is also 0.015 mm, and an opening is provided on the mold. The orientation degree of the block samarium cobalt permanent magnet prepared by using the device is 0.1°.

2. The device for preparing highly oriented samarium cobalt permanent magnet according to claim 1, characterized in that: There are two openings, which are symmetrically arranged on the front and rear sides of the mold.

3. The device for preparing highly oriented samarium cobalt permanent magnet according to claim 2, characterized in that: A connecting rod is also arranged at the opening of the rear side surface of the mold.

4. A method for preparing highly oriented samarium cobalt permanent magnets using the device according to any one of claims 1 to 3, comprising batching, smelting, powder making, molding, sintering, heat treatment, and processing steps, characterized in that: In the molding process, the device according to any one of claims 1 to 3 is used, and during the entire molding process, the upper transmission shaft and the lower transmission shaft are kept in the mold cavity.

5. The method according to claim 4, characterized in that: During the forming process, the blank is loaded and taken out from the opening.

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