JPS62254413A - Manufacture of radial anisotropic ring-form sintered magnet - Google Patents

Abstract

PURPOSE:To form a high-performance and low-cost R-Fe-B radial magnet by applying a magnetic field in a specified direction to a kneaded substance which is put in a mold. CONSTITUTION:A magnet powder mainly consisting of R-Fe-B is mixed with an organic binder and kneading is done. A molded body obtained by injection molding of a kneaded substance in a magnetic field is sintered to form a sintered rare earth magnet M. A magnetic field is applied to the kneaded substance put in said ring-form cavity in a mold radially from the center of the ring-form cavity. Accordingly, a large radial sintered magnet M which is thin and has a large diameter (d) can be obtained without requiring the modulating process of the thickness (t) after sintering.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing an R-F$-B based radial anisotropically cast sintered magnet.

[Conventional technology]

・When making a radially anisotropic ring-shaped magnet using a conventional rare earth magnet mainly composed of samarium (Sfi) and cobal (GO), the sintering method is used to create a radially anisotropic ring-shaped magnet, with anisotropic direction and other O direction. 0 cracking due to sintering shrinkage due to 0 difference in linear expansion coefficient vs.
Due to such reasons, it is difficult to make JtJ construction (regardless of the manufacturing method, such as compression molding or injection molding, as shown in Japanese Patent Application Laid-Open No. 140335/1983), and it is difficult to make JTJ construction, which has excellent impact resistance. Manufactured by resin bonding method.

[Problem that the invention seeks to solve]

In the case of radial anisotropic ring-shaped resin-bonded magnets, which contain 10 to 40 volumes of non-magnetic resin, the performance is much higher than that of sintered magnets.
) mz) was reduced to less than half. Recently, radial anisotropic ring-shaped sintered magnets using IAIt-yε-B-based sintered magnets, which have excellent magnetic performance and are free from zero cracking during contraction, cracking during magnetization, and chipping, have appeared. However, Ry, -B based sintered magnets are manufactured using compression molding and then sintering (Japanese Patent Laid-Open No. 59
46008), the wall thickness of the molded product is thin, such as ring-shaped magnets, which causes uneven filling when filling the mold with magnet powder, which causes deformation and distortion during sintering. Rounding is problematic because in order to produce it stably, it is necessary to thicken the wall of the molded body and process it to an appropriate thickness after sintering.

There are problems such as an increase in cost and a zero decrease in magnetic performance due to processing deterioration.

The present invention solves the problems as follows.

The purpose is to provide a method for manufacturing a sintered radial anisotropic ring-shaped sintered magnet O that requires sintering VKO processing.

[Means to solve the problem]

The method for producing a radial anisotropic ring-shaped sintered magnet according to the present invention involves mixing magnet powder mainly composed of R-S$-Bt-with an organic binder and performing aH, and then stirring the O kneaded product in a magnetic field. In a method for manufacturing a rare earth sintered magnet in which a molded body obtained by injection molding is sintered, a magnetic field is applied to the kneaded material filled in a ring-shaped cavity in a mold from the center of a ring-shaped cavity. It is assumed that t-is is applied in the radial direction.

The R-'IPg-B system magnet O rare earth element used in the present invention includes combinations of 01 and 2fi or more of θ elements from lanthanum (I6) containing yttrium (7) to lutetium (IJt&), Also, C#-jijim■ Like C#
- A mixed dilution consisting of praseodymium (Pr)-neodymium (lid) may be used, and Fe01it-
Co and aluminum (Muriar 6 also includes those converted to II with elements such as niobium (1&). The organic binder used is (consisting of Netsumachi ma resin, lubricant, and machisei agent, BV mu) polystyrene. , polyethylene Vk uses O-thermal resin such as polyvinyl alcohol, Q metal soap such as zinc stearate and aluminum stearate as a lubricant, diethyl phthalate, dibutyl phthalate, etc. as a slip agent.Magnetic powder and organic binder are used as a patch. The kneaded mixture of formula (1) is sufficiently kneaded using a continuous kneading FIAt-, and this kneaded product is granulated using a granulator.

The O granules are placed in an injection molding machine and sintered at the edges of the injection molding in a magnetic field applied in the radial direction.

Sintering atmosphere is argon (Mr) gas, hydrogen (Hs)
Any gas or vacuum may be used.

[Example-1] Figure 3111 shows a process diagram showing the manufacturing method of the present invention.
Composition ratio is C61ael'rs, *Nd64Dy14Fs
A cast ingot represented by +HGo lo's is prepared in a low frequency melting furnace in a low frequency melting furnace.The cast ingot is coarsely ground in a rod mill, and then finely ground in a ball mill until the average particle size becomes approximately 5 μsK. The powder obtained after pulverization is mixed with an organic binder at the proper blending ratio shown in Table 1, and injection molded under the molding conditions shown in Table 2. 6 in vacuum
Perform binder removal treatment at 00°C for 8 hours, and then
After sintering in gas at 1060°C for 2 hours, it is rapidly cooled.

A test piece was cut out from the obtained sintered body of φ18×φ15xt3 (scg), and it was magnetized in a 49KOtQ magnetic field and measured with a vibrating sample magnetometer.The results are shown in Table t-g3. The comparison column shown is 0 when a conventional O-resin bonded radial anisotropic ala stone was similarly cut out and measured.

From Table 3, tl/X3, it can be seen that the invention n has a performance that is more than twice as high as that of the comparison series.

[Implementation row-2] The process diagram of the manufacturing method using conventional Q press molding is shown in the wX2 diagram.
A cast ingot 1 made of aMb4Bm is prepared in a low frequency melting furnace in IR gas. Using this O casting ingot, a magnet T- is made according to the fermentation method shown in Figures 1 and 2.

The shape of the molded body is φ12 x φ7 x t 4.5 (w
) and φ23Xφ19 1.5 weight ratio was added, blended spinning and granulation were carried out, and Oll O (KO+++) Oa 2.5
Molded with totlΔ-.

The resulting molded body was debindered at 400° C. for 2 hours, sintered at 1060° C. for 3 hours, and rapidly cooled.

The obtained magnet was measured with a vibrating sample type magnetic needle, and the magnetic specific capacity and magnet O non-defective rate are shown in Table WX4. 2
According to the method of presentation in Table 4 of the present invention, which refers to products within 1%, magnetic performance is almost the same as in the comparison column, but the quality of products is much better, and it is very useful for reducing costs. I can stop.

[Actual tIA sequence-3] Using the two manufacturing methods shown in Figures 1 and 2, % C-Sakaki P-C Md-m”yl, al@Co饥B-
A radially anisotropic ring-shaped sintered magnet with the composition is created. 1iB5c) Shape φ20Xφ18Xt4(I
u) It is C' ring shaped. In the conventional manufacturing method, O-ring magnets with a wall thickness of 1 (M) in the sintered state have poor yields and cannot be put into practical use.
It was created by grinding the outer periphery of an O magnet. The Qal characteristics of this 020 magnet are shown in Table 115.

Table 5 Comparison row The decrease in Ogi properties to 0 is thought to be due to processing deterioration, and the method of the present invention, which does not require post-processing and can obtain a sintered body with precise dimensional accuracy, is superior in terms of performance and cost. It can be said.

[Run 4] The radial magnet shown in FIG. 3 is made using the present invention and conventional manufacturing methods. When the outer diameter of the ring is d = 24 (mm) and the height is h - 4 (m), the limit I [that allows the manufacture of a sintered magnet by reducing the wall thickness of 10 squares was determined. Similarly, t=1.5 (sa), Roux 4 (w)
When the size was 10, the limit value at which a sintered magnet could be manufactured was determined by increasing do[. OL and dC) Cough by manufacturing method are shown in Table 6.The manufacturing conditions are the same as in Example 2 except for the shape and size of the molded O.9For the manufacturing method of the present invention and conventional press molding, Table 1E6 It is possible to obtain thin-walled and large-diameter radial sintered magnets without requiring O processing after sintering.

[Invention Q effect]

As described above, according to the present invention, R-11P$-
The use of injection molding as a manufacturing method for B-based radial anisotropic ring-shaped sintered magnets has the effect of making it possible to manufacture high-performance, low-cost radial magnets.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the manufacturing method of the present invention. FIG. 2 is a diagram showing a conventional O1+j manufacturing method. FIG. 3 is a diagram showing a radial anisotropic ring-shaped sintered radial magnet prepared in the practical row. d-...Outer diameter 1-...Thickness h...Height or more Applicant: Seiko Epson Corporation Figure 1 Figure 2

Claims (1)

[Claims] Magnet powder containing rare earth (R), iron (Fe), and boron (B) as main components is mixed and kneaded with an organic binder, and the kneaded product is injection molded in a magnetic field, and the resulting molded body is sintered. A radial anisotropic ring characterized in that a method for manufacturing a rare earth sintered magnet comprises applying a magnetic field to the kneaded material filled in a ring-shaped cavity in a mold in a radial direction from the center of the ring-shaped cavity. A method for manufacturing a shaped sintered magnet.