JPS62151541A - Improved permanent magnet material - Google Patents

Abstract

PURPOSE:To produce a permanent magnet material having improved coercive force without requiring an intricate operating stage by adding a specific ratio of metallic oxide materials to the permanent magnet material consisting of rate earth elements, Fe, and B expressed by the specific formula. CONSTITUTION:1 or >=2 kinds of crystalline material and amorphous materials essentially consisting of the metallic oxides are added at <=1wt% (exclusive of 0) to the compd. expressed by the compsn. formula R1-x-yFexBy. R in the formula is 1 or >=2 kinds of the rare earth elements including Y and are specified to 0.55<=x<=0.85, 0.01<=y<=0.15. The crystalline or amorphous materials essentially consisting of the metallic oxides which soften or melt at the temp. lower than the m.p. of an R-Fe-B alloy are preferable, and lead oxide, bismuth oxide, silicon oxide, etc. are used. The permanent magnet material which is improved in the coercive force and has the small variance of the coercive force is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical field to which the invention pertains The present invention mainly relates to rare earth metals (R), iron (Fe) and boron (
The present invention relates to a permanent magnet material improved by adding a metal oxide material to the permanent magnet material consisting of B).

Conventional technology In recent years, the maximum energy product ([3t-
1) High-performance R-Fe-B magnets with n+ax ranging from 30 MGOe to 40 MGOc have been announced. For example, the report by Orial et al., “N eV M at Orial f
orPer+++anent Maqnets on
a Ba5e or Nd andFO” (29th
3M Conf, 1983 booklet p
.

110, 5essionEB, EB-1)
manufactures an anisotropic magnet material by a so-called powder metallurgy method in which crystalline Nd-Fc-B powder is molded in a magnetic field and sintered.

Recently, improvements such as coercive force Hc, residual magnetic flux density 3r, and direction of maximum energy product (81-1) max have been made through thermal aging treatment and the addition of various elements to the alloy. The Fe-B permanent magnet is the permanent magnet material that can be seen from the far right.

It has been known that thermal aging treatment is effective for changing the coercive force of the R-Fe-B alloy faE. This is because the grain boundary phase appearing in the alloy is soft magnetic bcc.
This phase increases the coercive force by making the grain boundaries smoother.

However, this method is still not sufficient, and there are large variations depending on the process, making it difficult to stabilize the quality.

Multi-stage thermal aging treatment is also performed to stabilize quality, but this has the disadvantage of making the manufacturing process even more complicated.

On the other hand, attempts have been made to add various metal elements to R-Fe-B alloys, but although these methods are effective in improving residual magnetic flux density, maximum energy product, and temperature characteristics,
Coercive force hardly improves.

Problems to be Solved by the Invention The object of the present invention is #1 to increase the coercive force of an R-Fe-[3 series alloy magnet without requiring complicated operation steps.

The present inventors believe that by adding impurities that do not easily react with the R-Fe-8 component to the grain boundaries of the alloy, they can act as so-called pinning sites, suppress the movement of the domain wall, and improve the coercive force. After considering various additives, we found that crystalline materials and amorphous materials mainly composed of metal oxides have extremely excellent effects.

Means for Solving the Problems The present invention has the following features: △) Compositional formula R1-X-V Fe X BV
A compound represented by (where R is one or more rare earth elements including Y, and 0.55≦x≦0.85.0.0
1≦y≦0.15), one or more of (B) a crystalline material and an amorphous material containing a metal oxide as a main component,
This permanent magnet material is characterized in that 1% or less (however, excluding O) of lff1 is added to the total of (A) and (B).

R in the composition formula R1-x-y Fe x By is a rare earth element containing Y, that is, YlLa, Ce, Pr,, Nd
, Pn+, Ss, Eu, Gd, Tb, Dy, Ho.

One or more of Er, Tl1l, Yb, and LLI are used.

The crystalline or amorphous material containing gold BM as a main component may be one that softens or melts at a lower temperature than the melting point of the R-Fc-B alloy, and preferably has a softening point or melting point of R.
-Fe Use a temperature lower than the sintering temperature of the -8 alloy material. Examples of this material include crystalline or amorphous glass, metal oxides such as lead oxide, bismuth oxide, and silicon oxide. These may be used alone or in combination of two or more.

The permanent magnet material of this invention has improved coercive force compared to conventional materials by blending a crystalline material or amorphous material whose main component is a metal oxide with the R-Fe-8 alloy. However, it also has the advantage that the variation in coercive force is reduced.

A material containing a metal oxide as a main component is added to and mixed with an alloy at the time of crushing the R-Fe-B melted alloy or at the time of molding the alloy powder in the process of manufacturing a magnet using a powder metallurgy method. The obtained mixed powder was prepared according to the conventional method (if
f is formed in-situ and then sintered.

During sintering, almost no reaction between the alloy and the oxide occurs; first, the metal oxide material softens or melts and acts as a flux at the grain boundaries, smoothing the grain boundaries and causing R- Fe
-8 abnormal grain growth can be suppressed. Therefore, since the unit (4i section) becomes smaller and exists as an impurity at the grain boundary, the movement of the domain wall is suppressed, and this is thought to have the effect of improving the coercive force necessary for a permanent magnet. Densification due to effect remains W
I16 flux density, leading to an improvement in maximum energy product.

Money! Crystalline or amorphous materials containing oxides as a main component have the effect of improving coercive force even with a small amount of m, but if too much a is added, the maximum energy product tends to decrease along with the residual magnetic flux density. Therefore, the limit is 1% for heavy machinery.

In addition, in R1-x-y Fc x By, 0.55
The reason why ≦×≦0.85 is set is that ``If the amount of e-gold is too large, the coercive force will be extremely small and the function as a permanent magnet material will be impaired, and if it is too small, the residual magnetic flux density will be low and the maximum energy product will also be This is because the range of y is set to 0.
The reason for setting it to 0.01 or more and 0.15 or less is because if the B-containing Ed increases, the residual magnetic flux density will decrease, and if it is too small, the coercive force will decrease.

Examples Example 1 An alloy having the following compositions: Nd 2 O, +5FQ O, 75B o, +o was melted in an argon atmosphere using a high frequency furnace. Next, the ingot alloy was coarsely ground using a stamp mill, and then ground to an average particle size of about 3 sv using a pot mill. A lead borosilicate glass frit having a softening point of 500° C. was added to this in an amount of 0.1% by weight and mixed. This mixed powder was mixed in a magnetic field of 10KOe with a
, 5t/c pressure was applied to form the mold, and the obtained molded body was sintered at 1100°C for 1 hour in an argon atmosphere, then rapidly cooled to air temperature, and further heat treated at 600°C for 1 hour. Manufactured a magnet.

The residual magnetic flux density (Sr) and coercive force (e
Hc, tHc) and maximum energy product (BH)
When max was investigated, the results shown in Table 1 were obtained.

Examples 2 to 6 Magnets were manufactured in the same manner as in Example 1 except that the amount of glass frit added was as shown in Table 1, and the characteristics are shown in Table 1.

Comparative Example 1 A magnet was manufactured in the same manner as in Example 1 except that no glass frit was added, and the characteristics are shown in Table 1.

Comparative Example 2 A magnet was produced in the same manner as in Example 1 except that the addition m of glass frit was 1.5i1fi%, and the characteristics are shown in Table 1.

Table 1 Examples 7 to 12 Conducted using alloys with the compositions Ndo, +3FQ O, 78BO, Q9, and crystalline zinc borate glass with a softening point of 620°C as the glass frit in the conditions shown in Table 2. A magnet was manufactured in the same manner as in Example 1. Investigate the characteristics of this magnet,
It is shown in Table 2.

Comparative Example 3.4 Addition amount of glass frit]- was O and 1.5ff, respectively.
A magnet was manufactured in the same manner as in Example 7 except that i was 1%, and the characteristics are shown in Table 2.

Examples 13-18 Ndo, +o Pr O, 05FQ O, 75B o
A magnet was manufactured in the same manner as in Example 1 using alloys having the compositions , +o and barium sodium silicate glass having a softening point of 740° C. as shown in Table 3 as the glass frit.

Table 3 shows the characteristics of this magnet.

Comparative Example 5.6 Magnets were produced in the same manner as in Example 13, except that the amounts of glass frit added were Oll and 5%, respectively, and the characteristics are shown in Table 3.

Table 2 Table 3 Effects of the Invention As is clear from the examples, the permanent magnet material of the present invention has improved coercive force compared to the conventional R-Fe-B optical material, and has a high residual magnetic flux density (lf t!). It has the highest energy product and is an extremely excellent magnetic material in practical use.

Claims (1)

[Claims] 1(A) Composition formula R_1_-_x_-_yFe_xB_y
A compound represented by (where R is one or more rare earth elements including Y, 0.55≦x≦0.85, 0.0
1≦y≦0.15), and (B) one or more types of crystalline materials and amorphous materials containing metal oxide as the main component, and the blending amount of (B) is 1% by weight. A permanent magnetic material that is as follows (excluding 0):