JPH062930B2 - Rare earth permanent magnet - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rare earth permanent magnet made of an alloy of a rare earth metal, a transition metal and a semimetal or a semiconductor element.

[Prior art]

Currently used industrial rare earth magnets are SmCo ₅ , Sm (TM) ₁₇
(However, TM represents a transition metal), and Nd-Fe
-B system etc. The rare earth metal used in these magnets is a separated rare earth obtained from ores such as monazite and bastnasite by ion exchange method or solvent extraction method. With separated rare earth, there are problems such as anxiety about the supply amount. For this reason, it has been attempted to develop a low-cost rare earth magnet by using a low-cost mixed rare earth metal (miss metal, hereinafter abbreviated as MM). The magnetic performance of the magnet using MM as the rare earth component is such that the residual magnetic flux density (hereinafter, abbreviated as Br) 8100 in the case of a sintered magnet of MMco _5.
(G), intrinsic coercive force (hereinafter abbreviated as iHc) 9000
(Oe), maximum energy product (hereinafter abbreviated as (BH) max) 14.5 ((MGOe) (H.Nagel, HPKleinAIP Conf.
Proc 24 695 (1974)) etc. have been reported. However, in general, permanent magnets using mixed rare earths have the drawback of low magnetic performance. Further, the Curie point (Tc) of the Nd-Fe-B system magnet, which has a relatively high magnetic performance,
Since it is as low as 350 (° C), it is considerably limited in actual use.

〔Purpose〕

The present invention solves such a problem, and an object thereof is to develop a low-cost and high-performance permanent magnet.

〔Overview〕

The permanent magnet of the present invention is a Ce-Di (didymium: Nd-Pr alloy) -Fe-Co-B system alloy, and a part of B in the alloy is Al, Ga, In, Sn, Pd, Bi, C, Ge,
It is characterized in that it is manufactured by a sintering method or a resin bonding method using an alloy substituted with one or more elements of the P and S element groups. The mixed rare earth metal Ce-Di is obtained in the process of extracting the separated rare earth, and is much cheaper than the separated rare earth in terms of cost.
High magnetic performance can be obtained by defining the composition of the i-Fe-Co-B system, and by adding Co, T
The improvement of c was seen.

〔Example〕

 Hereinafter, the present invention will be described in detail based on examples.

Example 1 An alloy having the composition shown in Table 1 is melted in Ar gas using a low frequency melting furnace.

Solution treatment of the alloy at 1070 ° C. for 10 hours, 800 ° C.
After aging treatment for 4 hours, it is pulverized by a ball mill to obtain fine powder having a particle size of 2 μm to 80 μm. 2.0% by weight of epoxy resin is added to the magnetic powder and kneaded, and the mixture is compression molded in a magnetic field. This molded body is heated at 150 ° C. for 1 hour to obtain a permanent magnet. The magnetic performance of the obtained permanent magnet is shown in Table 2. It can be seen from Table 2 that the magnet of the present invention has very high magnetic performance as a magnet using mixed rare earth.

Example 2 The composition formula is Ce _0.4 Pr _0.1 Nd _0.5 (Fe _0.59-n Co _0.41
The value of n is changed in the system represented by B _n ) _5.6, and a permanent magnet is manufactured using the same method as in Example 1. The magnetic performance of the obtained permanent magnet is shown in FIG. It can be seen from FIG. 1 that the value of n is preferably in the range of 0.02 ≦ n ≦ 0.2.

<Example 3> composition formula _{Ce 0.4 Pr 0.1 Nd 0.5 (Fe} 0.50 Co 0.41 B
The value of z is changed in the system represented by _0.09 ) _z, and a permanent magnet is manufactured using the same method as in Example 1. The magnetic performance of the obtained permanent magnet is shown in FIG. It can be seen from FIG. 2 that the value of z is preferably in the range of 4.0 ≦ z ≦ 8.0.

<Example 4> composition formula _{Ce 0.4 Pr 0.1 Nd 0.5 (Fe} 0.91-m Co m B
Fig. 3 shows Tc of alloys in which the value of m is changed in the system represented by _0.09 ) _5.6 . T by adding Co
Although c is improved, it is disadvantageous in cost when 0.8 <m. Therefore, the value of m is preferably in the range of 0.1 ≦ m ≦ 8.

Example 5 An alloy having the composition shown in Table 3 is manufactured in the same manner as in Example 1 to manufacture a permanent magnet. The magnetic performance of this permanent magnet is shown in Table 4.

From Table 4, a part of B is Al, Ga, In, Sn, Pb,
It can be seen that good magnetic performance can be obtained even if the elements are replaced with Bi, Si, C, Ge, P and S.

<Example 6> The alloys having the compositions of sample Nos. 1 and 7 in Examples 1 and 5 are melted in Ar gas using a low frequency melting furnace. The alloy is made into a fine powder having a particle size of 2 μm to 5 μm by a ball mill. This powder is compacted in a magnetic field and the compact is
After sintering at 100 ° C. for 1 hour, solution treatment is performed at 1070 ° C. for 2 hours, rapid cooling, and further aging treatment at 800 ° C. for 4 hours to obtain a permanent magnet. The magnetic performance of this permanent magnet is shown in Table 5.

When the magnet of the present invention is manufactured by the sintering method, it has magnetic performance comparable to that of the SmCo ₅ sintered magnet.

<Example 7> Powders having a particle size of 2 to 80 µm are prepared in the same manner as in Example 1 for the alloys having the compositions of sample Nos. 1 and 7. This powder is kneaded with a resin and molded in a magnetic field by an extruder and an injection molding machine. Table 6 shows the molding conditions, and Table 7 shows the magnetic performance of the permanent magnets obtained.

[Effects] As described above, according to the present invention, it is possible to supply high-performance rare earth permanent magnets at low cost, and it can be said that the effects on the industry are great.

[Brief description of drawings]

 FIG. 1 is a graph showing the relationship between the value of n and the magnetic performance of the magnet. FIG. 2 is a graph showing the relationship between the value of z and the magnetic performance of the magnet. FIG. 3 is a graph showing the relationship between the value of m and the increase amount of Tc.

Claims (2)

[Claims] 1. A atomic _{ratio, Ce 1-xy Pr x Nd} y (Fe 1-mn Co m B n) rare earth permanent magnet, characterized in that an alloy composition represented by _z. However, x, y, z, m, and n are as follows: 0.1 ≦ x ≦ 0.5 0.1 ≦ y ≦ 0.85 4.0 ≦ z ≦ 8.0 0.1 ≦ m ≦ 0.8 0 .02 ≦ n ≦ 0.2 0 <1-x−y ≦ 0.8. In wherein the atomic _{ratio, Ce 1-xy Pr x Nd} y {(Fe 1-s T s) 1-mn Co m B n}
A rare earth permanent magnet comprising an alloy having a composition represented by _z . However, T is Al, Ga, In, Sm, Pd, Bi, S
i, C, Ge, P, S consisting of one or more elements of each element, x, y, z, s, m, n: 0.1 ≦ x ≦ 0.5 0.1 ≦ y ≦ 0.85 4.0 ≦ z ≦ 8.0 01 ≦ S ≦ 0.1 0.1 ≦ m ≦ 0.8 0.02 ≦ n ≦ 0.2 0 <1-x−y ≦ 0. The value range is 8.