JPS58157118A - Manufacture of resin-bonded type rare earth cobalt magnet - Google Patents

Abstract

PURPOSE:To obtain a magnet with high orientation by a method wherein magnetic powder is magnetized in a state of a mixture with a resin before it is formed in a magnetic field stronger than the forming magnetic field to improve the degree of orientation of the powder. CONSTITUTION:The addition of a process before or after mixing wherein preparatory magnetization is performed in a magnetic field that is stronger that a forming magnetic field prepares magnetic powder to be sufficiently orientated even in a relatively weak magnetic field. Production of highly orientated magnets has thus become possible even in an industrially available forming magnetic fields. This method of improving orientation by magnetizing powder beforehand is more effective when it is employed in the treatment of materials of the R2TM17 type demanding a fairly strong field. Further, when Sm is used to be used as the rare earth element R, not only the 4xIs is larger, but also uniaxial anisotropy is higher at room temperatures, and anistropic energy is higher than other materials belonging to the R2TM17 type. A magnetizing field of not less than approximately 20kOe is required to obtain a good result.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a resin bonded rare earth cobalt magnet. That is, it relates to a manufacturing method in which the magnetic performance of a resin-bonded rare earth cobalt magnet is enhanced by magnetizing it in a magnetic field higher than the molding magnetic field after kneading it with a resin before molding or in the powder state before kneading. Rare earth cobalt magnets have much higher performance than ferrite magnets and alnico magnets. The manufacturing method includes a sintering method and a resin bonding method. Among these, 11 the fat bonding method has advantages over the sintering method, such as better workability, product homogeneity, lower cost, lower specific gravity, 9 higher mechanical strength, etc. On the other hand, as a result of containing at least 801% of something other than magnetic powder (resin),
With conventional manufacturing methods, magnetic performance (B H)! 11
4X had the disadvantage that it was about half the size of that produced by the sintering method.

The present invention aims to solve this drawback by magnetizing the powder mixed with resin with a magnetic field higher than the molding magnetic field before molding to increase the degree of orientation of the powder. Figure 1 shows R for rare earths and TM for transition metals mainly composed of cobalt.
The manufacturing process of the RITMtT magnet is shown divided into a sintering method and a resin bonding method. FIG. 1 (1) illustrates the manufacturing process of BATMIT-based magnets using the sintering method. (1) and
A step of coarsely pulverizing (2) and finely pulverizing the alloy (1), a step of compression molding the pulverized RITMlf magnet powder in a magnetic field using a compactor (4), and a step of sintering the compression molded powder. (5), solution treatment line 1iA (6) and aging treatment line 1i (Y″) to further improve the performance of the magnet.
), the final step is magnetization! ! ! It consists of (j). In addition, Figure 1 (Figure 1) illustrates the manufacturing process using the resin bonding method, and shows the process of melting and casting the alloy (Qυ), the solution treatment process (B), and the aging treatment process performed to improve the performance of the magnet. mus, the step of coarsely pulverizing (b) and finely pulverizing the alloy (2), the step of kneading the resulting powder with resin (to), the step of pulverizing and kneading R1'1''M17 (b), and such compression molding. It consists of the step of applying a cure song to the powder and curing the resin (end), and finally the step of magnetizing it (step 2).From this figure, it can be seen that during magnetic field molding, the aging treatment is completed in the resin bonding method, but It can be seen that the sintering method is not yet finished.

FIG. 2(α) shows the hysteresis curve in the step (4) of FIG. 1 (the latest step), and FIG. 28iff(A) shows the hysteresis curve in the step of FIG. 1(A).

It can be seen that the shapes of the hysteresis curves are significantly different between the two. In other words, since aging treatment is a process to obtain the original coercive force of 1Ho, the resin bonding method, which has already undergone aging treatment at the time of magnetic field molding,
This is a hysteresis curve with a large iHo. Generally, in order to achieve sufficient orientation during magnetic field forming,
1) (It is said that a magnetic field about 3 to 5 times as large as a is required.

In other words, from Figure 2, the sintering method has a 5x to 10KO
While a magnetic field of e is sufficient, for the resin bonding method, 30! A magnetic field of ~50 KO· is required. FIG. 3 shows this in relation to the degree of orientation. (In this figure, the degree of orientation is set to 1 in the magnetic field of so to.) However, according to the conventional magnetic field forming machine as shown in Fig. 114, the gap between the magnetic field generating coils 1 is [To set I12, it cannot be made too small.

Therefore, it was difficult to generate a magnetic field of 20 KO• or more. Therefore, if the sintering method was used, it was possible to achieve sufficient orientation with the conventional 10-piece device, but if the resin bonding method was used, only incomplete orientation could be achieved, and the original performance of the magnetic powder could not be demonstrated. . In the manufacturing process 11 (first EI (A)) of resin-bonded rare earth cobalt magnets, the present invention includes a process in which magnetization is carried out in advance with a magnetic field higher than the forming magnetic field after or before resin cross-talk (FIG. 5 C16). ′))
In addition, it has been discovered that if a manufacturing process such as the 5th wA is used, the magnet powder can be sufficiently oriented even with a relatively low orientation magnetic field, and the drawbacks of the conventional manufacturing method can be solved. In other words, the present invention provides a high degree of orientation even in an industrially possible i&-type magnetic field. This makes it possible to manufacture resin-bonded rare earth cobalt magnets. Furthermore, the present invention is more effective when used for RTM17-based rare earth cobalt magnet magnet powder than for RTMs-based magnet powder. Figure 6 shows the RTMs system and R1TM17
This figure shows the hysteresis curve and initial magnetization curve of the resin-bonded rare earth cobalt magnet. In the R1TM17 series, the initial magnetization curve rises very slowly compared to RTMs J. In other words, as shown in the figure, when applying the magnetic field H1 just before the vJ magnetization curve of the R2TM17 system rises, 4x
There is a note that there is a big difference in the work value between the two threads. In other words, RTMII-based materials are easily oriented with a small magnetic field, while R1TM17-based materials require a considerable magnetic field for orientation. Therefore, the magnet powder is magnetized in advance to enhance its orientation. This manufacturing method is highly effective. and l
By adding 10 in addition to OO as the 118 metal TM, the saturation magnetic flux density [Br increases, and by adding O, an RTMI-based compound, which is the basis of the coercive force of the RzTMxtii4 rare earth cobalt magnet, is obtained, and Zr.

By adding If, Wb, Ti, etc., RTMiM
It has been confirmed that the precipitation of compounds is promoted, and by skillfully combining these, higher performance RITM17
system magnets can be created. Furthermore, among the rare earths R, most of the RITMIT magnets that are industrially mass-produced use Sm as R. This is because the R2TM17 system generally has a higher saturation magnetization 4π knee than the RTMI system, which is advantageous for manufacturing high-performance fIA magnets, but among them, those using Sml as R are
Not only does it have a high 4π knee, but it also has a large uniaxial anisotropy at room temperature and an anisotropy energy of RITMI? This is because it is large in the system. Next, in order to effectively utilize the present invention, a magnetization of about 20 sections or more is required. As mentioned above, with the conventional magnetic field forming machine, approximately 2 Q KO・
is the critical magnetic field, but in the case of resin-bonded rare earth cobalt magnets, a magnetic field of 30 to 50 x O· was required for sufficient orientation.

When magnetizing powder, unlike a molding machine, there is no need to set a molding section, so the gap between the mail pieces of the magnetic field generating coil can be reduced, and the generated magnetic field can be increased. In this manufacturing method, the degree of orientation of the powder is increased by magnetizing with a magnetic field higher than the forming magnetic field, so the magnetizing magnetic field must be increased as much as possible. At this time, at least about 20! If there is a magnetic field of O. or more, 50 KO
Since it is possible to obtain a magnetic performance of about 98≦ when magnetized with e or more, the present invention can be effectively utilized.

Example (1) First, composition S N (oo@, @720uo, os Fs
o, zzZr@, eaa) s, s alloy 1 and s m
(Ooo, 5ozOus, eys 1eo, s Zr
s, os) t, s alloy 2 and (S!110.7Pro,
s) Melt the three alloys of alloy 3 of +00m.

Next, Alloys 1 and 2 were subjected to solution treatment at a temperature range of 1150 to 1190°C under a murky atmosphere, and then heated to a temperature of 800 to 850°C.
A multi-stage aging treatment is performed in the same temperature range under the same atmosphere. Then, alloy 1,2゜3 is pulverized and the particle size is adjusted, and then kneaded with epoxy resin.The resulting kneaded powder is newly named powder 1.2゜3.

Figure 7 shows the change in the value of the maximum energy product (BH) wm*x when powders 1 and 2.3 are magnetized with various magnetic fields of 15 to 30 KOe and then molded with a forming magnetic field of 15 KO.
Shown below. As can be seen from the figure, as the magnetizing magnetic field increases, (III) m&x of JTM17 powder 1°2 increases greatly, but as mentioned above, the effect of the present invention is small in RTML powder 3.

Example (2) Powder 2 produced in Example (1) was magnetized with a magnetic field of 3QIOe.
Figure 8 shows the changes in the residual magnetic flux density [mr] when magnetized with 1 and then molded in various magnetic fields of less than 20 KO. It can be seen from the figure that if magnetization is performed, at least a large radius r can be obtained for the forming magnetic field. In other words, since Br is a measure of the degree of orientation, by magnetizing it, a magnet with a large degree of orientation can be obtained even with a small magnetic field.

Example (8) Squareness (S Q = −e
iH.

FIG. 8 shows the change in the strength of the demagnetizing field (Hk is the strength of the demagnetizing field when 4π work indicates a magnitude of 90≦Br). JTM17 series powder 1
In the case of (Bill) IIIL shown in Example (1)
Not only X but also the aQ value increases as the magnetizing magnetic field increases. However, ITM, yarn powder 3 is (BH) wax, 8q
The effect of magnetization is small for both values.

As described above, according to the present invention, after mixing rare earth cobalt magnet powder and resin, the manufacturing method is first magnetized in a higher magnetic field than the molding magnetic field, and then magnetic field molding. The drawbacks of rare earth cobalt type magnets have been overcome, and it has become possible to obtain magnets with a high degree of orientation even with a low forming magnetic field. Currently, the present invention is being applied not only to Oshio magnets for printers and motors, but also to small magnets such as rotor magnets for watches, and has been well received.

[Brief explanation of the drawing]

Figure 1 is a leakage diagram showing the manufacturing process of R1TM□7 rare earth cobalt magnets, divided into sintering method (1) and resin bonding method (b), Figure 2 (cL) (j) is the same as Figure 1 5 is a graph showing the relationship between the forming magnetic field and the degree of orientation depending on the manufacturing method, and FIG. 4 is a schematic diagram of the magnetic field forming machine.1. ...
・Magnetic field generation coil, 2... Molded lug, 5...
... Cylinder, 4... Forming punch. FIG. 5 is a flowchart of the manufacturing process of a JTMlj-based resin-bonded heavy rare earth cobalt magnet using the present invention with the addition of a preliminary magnetization step (15'). The 6th gI is the RTMi system and J TMIT
Graph showing the hysteresis curve and initial magnetization curve of the resin-bonded rare earth cobalt magnet. Figure 7 shows (B
H) Graph showing changes in wax. FIG. 8 is a graph showing how the residual magnetic flux density Br changes depending on the change in the shaping magnetic field when magnetized at 30xO・ and when not magnetized. FIG. 9 is a graph showing changes in the 8Q value when the magnetizing magnetic field is changed to a certain IM magnetic field of 15[o. Applicant: Hekiha Seikosha Co., Ltd. Figure 2 Figure 3 Figure 5 Figure 7

Claims (1)

[Claims] (1) A resin-bonded magnet, characterized in that rare earth cobalt magnet powder and resin are mixed, firstly magnetized as MS stone powder in a magnetic field higher than the molding magnetic field, and then subjected to magnetic field molding. Earth! Method for manufacturing I cobalt magnet. (2) As a rare earth cobalt magnet powder wheel, R3 uses a rare earth as a trap and a transition metal mainly composed of cobalt as a TM.
! A method for manufacturing a rare earth cobalt magnet with *m crystallization as described in item (1) of patent claim omim, characterized in that MIT-based magnet powder is used. (m) *as 8! Current review request 011 characterized by using l! lI rattan resin-bonded rare earth I described in item (2)
Il: 2 Method of manufacturing Baltic magnet. (4) Patent claim 0 @ Enclosure (1), α) or (a) characterized in that the magnetizing magnetic field is set to rt2010.
Any &: A method for producing a bankruptcy bonded rare earth cobalt magnet.