JPS59163804A - Permanent magnet - Google Patents

Abstract

PURPOSE:To realize the magnetic characteristics equal to or higher than those of hard ferrite by adding dopant elements M such as Ti, Ni and Bi and small quantity elements X to FeBR ternary base alloy. CONSTITUTION:A permanent magnet which is a sintered body of a magnetic anisotropic material is composed of following components (% means atomic percent): 8-30% of R (R means at least one of rare-earth group elements including Y.), 2-28% of B, prescribed % of dopant elements M (less than 4.5% of Ti, less than 8.0% of Ni, less than 5% of Bi, less than 9.5% of V, less than 12.5% of Nb, less than 10.5% of Ta, less than 8.5% of Cr, less than 9.5% of W, less than 8.5% of Mn, less than 9.5% of Al, less than 2.5% of sb and so on), prescribed % of small quantity elements X (less than 3.5% of Cu, less than 2.5% of S, less than 4.0% of C and less than 3.5% of P) and the remainder of Fe and inevitable impurities for manufacture. Summation of M and X should be less than the percentage of the element which has the largest percentage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel permanent magnet represented by the formula FeBI'tMX. In the present invention, the symbol R includes Y and represents a rare earth element. M is an additive element such as AI, Ni, Mn, etc., X is Ou
, P, O, and S.

Permanent magnetic materials are extremely important electrical and electronic materials used in a wide range of fields, from various household appliances to peripheral terminals for large computers. Electricity in recent years
With the demand for smaller size and higher efficiency of electronic devices, permanent magnet materials are required to have increasingly higher performance.

Current representative permanent magnet materials are alnico, hard ferrite and rare earth cobalt magnets. Due to the recent instability in the raw material situation for cobalt, cobalt
The demand for alnico magnets containing 0% by weight has decreased, and inexpensive hard ferrite, whose main component is iron oxide, has become the mainstream magnet material. On the other hand, rare earth cobalt magnets contain 50 to 65% cobalt by weight and are very expensive because they use Sm, which is not contained in rare earth ores, but they have much higher magnetic properties than other magnets. For,
It is mainly used for small magnetic circuits with high value.

In order for rare earth magnets to be used cheaply and in large quantities in a wider range of fields, it is necessary to create magnets that do not contain expensive cobalt and whose main component is light rare earth metals, which are found in large amounts in ores. It is necessary. It has been desired for a long time to realize such a permanent magnet that has magnetic properties as high as or better than conventional Burt Noelite for practical use.

That is, the basic object of the present invention is to meet the above-mentioned problems.

As a permanent magnet material that should meet this fundamental purpose, the present inventors first discovered a 1ρc B I' (, system permanent magnet), and filed a patent application (Patent Application 1983-
145072). This FeBTl-based permanent magnet does not contain Co and is a resource-rich material mainly containing Nd and Pr as R.
! 25MG using rich light rare earths and Fe as the main component.
It exhibits an extremely high energy product exceeding Oe. Compared to conventional alnico magnets and rare earth cobalt magnets, this magnet has
It has high properties at lower cost. That is, it provides higher cost performance and has great industrial utility.

The coercive force 11Tc of this Ii'e BR magnet is IKO
1TTc, a rare earth cobalt magnet that reaches a maximum of approximately 13 KOe from e and is currently known as the magnet with the highest characteristics.
It's so thick that it's comparable to. However, in recent years, permanent magnets have been exposed to increasingly harsh environments - for example, strong demagnetizing fields due to thinner magnets, strong countermagnetic fields applied by coils and other magnets, and in addition to the increasing speeds and high loads of equipment. In many applications, even higher coercive force is required to stabilize the characteristics (generally speaking, permanent magnets are exposed to high temperature environments due to temperature rise). Therefore, 1lT at room temperature
If c is small, demagnetization will occur when the permanent magnet is exposed to high temperatures. However, if iHc at room temperature is sufficiently high, such demagnetization does not substantially occur. ).

This Fc-B・1 (, ternary permanent magnet is useful as such, but as a result of further experimental investigation, this Pe −
B −■(, other additive elements M (Ti, N
i.

Bi, V, Nl), Ta, Or, Mo,
W, Mn, AI, Sb, ()e.

One or more of Sn, Zr, Hf''-) and a minor element X (
Ou.

It has been revealed that a magnetically anisotropic sintered permanent magnet having a magnetic property higher than that of hard ferrite can be obtained in a new composition containing a predetermined amount or less of at least one of p, c, and s.

In addition, the present invention has a further secondary object of producing Fe-B・T (
The aim is to obtain a new permanent magnet (material) based on a ternary system. Furthermore, as a preferred embodiment, it is desired to obtain a permanent magnet having a coercive force that is sufficiently high for practical use and is equal to or higher than that of conventional products.

The present invention combines Fe, B/R ternary base alloy with Ti,
Ni, Bi, V, Nb, Ta, Or, Mo
, W., Mn., A.I.

Adding one or more specific additive elements M such as sb, Ge, Sn, Zr, I-If-1-1 and one or more minor elements X (Cu, S, 0°P) As a result, a practical magnetically anisotropic sintered permanent magnet having magnetic properties equal to or higher than that of conventional hard ferrite was realized. That is, the permanent magnet (material) of the present invention
is as follows.

In terms of atomic percentage, R of 8 to 30 (however, R is at least one type of rare earth element including Y), B of 2 to 28, and one or more types of additive elements M of a specified number (however, here The predetermined amounts of additive elements M are T145 or less, Ni 8.0 or less, Bi 5 or less, V'9.5% or less, Nb 12.5% or less,'
l”a I 0.5Sjg or less, Or 8.5% or less,
Mn 9.5% or less, W 9.5% or less, Mn 8.
0% or less, A19.5'% or less, Sb 2.5% or less, Ge 7% or less, Sn 3.5% or less, Zr 5
．． 5 or less and ITf 5.5 or less, excluding Mo), one or more of the specified small amount elements
2. O section and below, C4, O section and below, and P 3.5%
(excluding X0%) However, the total of M and (material).

Further, in the case where two or more of the additive elements M are included as the M, the total amount of M is less than or equal to φ of the maximum value of the additive elements M, and as the X, two or more of the minor elements The same applies when X is included.

Thus, in the present invention, the Pc B RMX magnet is
It is specified as having a sufficiently high coercive force for practical use and a residual magnetization equal to or higher than that of conventional nord ferrite.
``Industrial'' - Provide useful new permanent magnets (or discrimination).

In the I'e BT (-M
The composition range of B is basically the same as that of the FeBR ternary alloy (8-30 ratio R, 2-28 ratio B). That is, in order to satisfy the coercive force iHc > I KOe, B is set to 2 or more, and in order to make the residual magnetic flux density Br of the hard ferrite approximately 4 KG or more, it is set to 28 or less.

R is required to have a coercivity of 8 or more in order to make the coercive force more than IKOe, and it is also easily flammable and difficult to handle and manufacture industrially (
(and is also expensive), it should be 30 fissures or less. This B
, R range, the maximum energy product (r3H) may be equal to or higher than that of hard ferrite (about 4MC40e).

Light rare earth is the main component of R1 (i.e. 50 atoms or more of light rare earth in total R), and the composition of 11-24% R, 3-27% B, and the balance (Fe1M+X) is based on the maximum energy product (Bf-I
) This is a preferable range in order to satisfy max≧7MGOe.

Most preferably, the main component of R is a light rare earth, and 12 to 2
0% TL, 4-24% B, balance (Fe + M + X)
, and the maximum energy product (BH) max≧10M
C] Oe is possible, (B FI ) may be at most 2
Reach more than 5 MGOe.

The permanent magnet of the present invention has the above-mentioned 8 to 30% R, 2 to 28% B,
Additive element M in the entire range of remaining Fe (atomic percentage)
, and the effectiveness of a small amount of element X has been confirmed, and this Fe
It is not effective outside the range of BT (,. Furthermore, the permanent magnet of the present invention is generally
It is an alloy system with a novel crystal structure and exhibits a single point at around 370°C.

The additive element M has the effect of increasing the iHc of the FeBR ternary system. This tendency is as shown in FIGS. 1 to 6, and can be discussed separately from the effect of containing a small amount of element X.

By containing this M, the permanent magnet of the present invention exhibits a coercive force sufficient for practical use, and in a preferred embodiment, can be obtained that exceeds hard ferrite and is comparable to or even superior to Sm0o-based magnets.

The present inventor has discovered that Ii"e Bn, series ternary alloys, especially 8-
Pea consisting of 50chi R, 2 to 28chi B1 remainder Fe
Based on the R ternary alloy, with the goal of improving its coercive force, we aim to improve the coercive force of most elements, excluding radioactive elements, from the trace amount range ((), OQ5 atomic coefficient, hereinafter the coefficient indicates atomic quantity). We have investigated in detail the changes in coercive force and other magnetic properties due to the addition of the additive element M over a range of 20 to 30%.As a result, we found that the addition of the additive element M has the effect of imparting even higher coercive force to FeBR, ternary magnets. I found out.

However, it has also become clear that the addition of these additive elements M causes a gradual decrease in the residual magnetization Br in each aspect. Therefore, the content of the additive element M is such that the residual magnetization Br is at least equal to or higher than the residual magnetization Br of conventional hard ferrite and exhibits the effect of increasing the coercive force. Ru.

Except for the additive element M, Bi, other elements T+, Zr
.

Hf, V, Ta, Nl], Or, W, Mo
, Sb, Sn, Ge, AA! -1- of the addition amount of
The limit is set as a range equivalent to or higher than the Br of hard ferrite, approximately 4KG, Ti below 4.5, Ni a,
ochi or less, Bi 5 or less, V9.5% or less,
Nl) 12.5% or less, Ta 10.5% or less,
Or 8.5% or less, Mo 9.5% or less, W9.5
% or less, Mn 8.0% or less, Al 9.5% or less, Sb 2-5% or less, Ge 7% or less, Sn
3.5% or less, Zr 5.5% or less and Hf
5.5 or below.

In addition, although the influence of M on Br is shown in graphs in FIGS. 1 to 3, as is clear from the Br characteristic curve, there is a preferable range with stages such as Br 6.5KG, 8, G, 10KG, etc. Can be set.

As for Bi, its vapor pressure is extremely high (it is virtually impossible to produce an alloy exceeding Bi5, so it is set to be less than 5.

In the case of an alloy containing two or more types of additive elements M, Br is 4K.
() In order to satisfy the above conditions, it is necessary that the amount of addition of each element be equal to or less than the maximum value (%) of the two upper limits of each element added. The Br characteristics in this case are obtained as a curve obtained by synthesizing the characteristic curves of each M shown in Figs. 1 to 6 according to the component ratio of each component, and the upper limit value thereof is determined by Take the intermediate value below the maximum value. This relationship is similarly applied to the relationship between the additive element M and the minor element X, and the relationship when two or more types of each of M and/or X are included.

As is clear from Figures 1 to 6, as the amount of additive metal M increases, Br decreases in most cases, and (BI-1) max is also shown in Table 1. decreases as shown. However, the increase in coercive force i I-1c is
High (B H,
) Like the max type permanent magnet, it is industrially useful.

When Mn and Ni are added in large amounts, the coercive force decreases.

Mn of 3.5% or less and Ni of 4.5% or less do not lower the coercive force than when no additive is added, so these are preferable ranges.

011 of minor element X. S, 0. P etc. are industrially F
When manufacturing an eBRM magnet, it is often contained due to the raw materials, manufacturing process, etc. For example, when FeB is used as a raw material, it often contains S, P, and C.
is an organic binder (forming aid) in powder metallurgy process
It is often contained as a residue. According to the present invention, the influence of these small amounts of element X has been found to be such that the residual magnetic flux density Br tends to decrease as its content increases.

As a result, the atomic percentage (the same applies below unless otherwise specified)
At 0113.5% or less, S2.0% or less, 04,0
% or less, P 3.0% or less (and the total of (approximately 4KG).

Further, as X, O is an inexpensive raw material iron with low purity, and some iron contains a large amount of O, and it is advantageous to include this within a limited range.

As shown above, the present invention has a sufficiently high coercive force for practical use due to the inclusion of the additive element M, and the inclusion of a small amount of the element X expands the selection range of raw materials and eases restrictions on manufacturing. A magnetically anisotropic sintered permanent magnet with a high energy product (BH) max has been realized.

In addition, when two or more types are included as the X component, the Br characteristics are as shown in Figs.
The total maximum value in that case, which is given by synthesizing the Br characteristic curves of each X component for the B11 ternary system according to their component ratios, takes a value less than or equal to the value of the component having the maximum value.

In order to improve the temperature characteristics of the FeBRMX permanent magnet of the present invention, a portion of Fe may be replaced with 50% or less of Co.

The inclusion of CO has the effect of raising the Curie point of the alloy.

By processing the alloy of the present invention by melting, casting, crushing, forming in a magnetic field, and sintering, it becomes a practical permanent magnet as a magnetically anisotropic sintered body having good magnetic properties.

However, with other conventional methods such as melting, casting, and aging methods used to manufacture alnico magnets, coercive force may not appear at all, and many other methods may not produce the desired results. Experimentally confirmed. The permanent magnet of the present invention is extremely unique in this respect.

The Pe13R, MX permanent magnet of the present invention is a magnet based on the Fe-B-R ternary system, and does not necessarily need to contain CO, and as R, a light rare earth, which is abundant in resources, can be used. However, since it does not necessarily require Sm or it does not need to be made mainly of Sm, the raw material is inexpensive and extremely useful.

The light rare earth is I (main component of (i.e., total R medium light rare earth 50 or more), 11-24, R13-27, B, the additive elements M and (BT-T) max≧7MGOe, which is a preferable range.

Most preferably, light rare earth is used as the main component of B, and 12 to 20
ratio R・, 4 to 24 ratio B, predetermined ratio of additive elements M and X,
The composition of the remainder Pe and the maximum energy product (B T-1)
max≧10MGOc, maximum 25M(]Oe or more)
It also becomes.

Note that the predetermined content of the above-mentioned X is extremely advantageous industrially because it allows the use of raw materials with low purity and enables easy and inexpensive production.

R, (!: t, Nd is more abundant as a resource than Sm, etc., and it is generally not used much, so there is a surplus of Nd. It is extremely advantageous to use it as the central element of an alloy.

In addition to Nd, R1 includes Pr, La, Oe, and T.
I), Dy.

T-1c, Er, Ell, Sm, Gd, Pm
, Tm, Yl), TJIJ and Y, among which light rare earths are sufficient, especially Nd, 1. 'r is preferred. Note that heavy rare earths are rare and expensive resources, and generally have little industrial utility value; however, heavy rare earths can be used alone or in combination with heavy and light rare earths. Generally, one type of R is sufficient, but in practice, a mixture of two or more (such as Mitsumemetal, didimium, etc.) may be used for reasons such as convenience. In addition,
This R1 does not need to be a pure rare earth element, and may contain impurities that are unavoidable in production within an industrially available range.

Pure boron or ferroboron can be used as B (boron), and Al can be used as an impurity.

A material containing Si or the like can also be used.

-I- The PeBRMX-based permanent magnet material contains the above-mentioned Fe, B
.

In addition to R, M, and X, the presence of impurities that are unavoidable in industrial production can be tolerated. It is also possible to partially replace B with N, Si, etc., making it possible to improve manufacturability and reduce costs.

Experimental Examples and Examples of the present invention will be shown below, but the present invention is not limited theretoG).

Permanent magnet samples of Pe-B-RM-X alloy containing various additive elements were prepared by the following method.

(1) The alloy is high-frequency melted and cast in a water-cooled copper mold. The starting materials are Fe with 999% purity electrolytic iron, B with ferroporon alloy and 99% boron, and the purity is 997 or more (no impurities Mainly other rare earth metals) are used, and as additive elements M, Ti and Mo with a purity of 99% are used.
.

Bi, Mn, Sb, Ni, Ta, 98% W
, 99.9% kl, 95% I-If, 99.9
% Ou, and 81.2% ferrovanadium as Nl), ferronniobium containing 67.6% Nb as Or, ferrochrome containing 619% Or and 755% as Zr. Ferrozirconium containing Zr was used.

As the minor element X, S with a purity of 99% or higher, ferroline containing 267% P, and electrolytic Cu with a purity of 99% or higher and 01 purity of 999% or higher were used.

(2) Coarsely pulverize to 65 mesh through using a crushing stamp mill, then finely pulverize for 6 hours using a ball mill (3
~10μm), (Orientation and forming in 3 magnetic fields (10KOe) (1.5t/c
(4) Sintering at 1,000 to 1,200°C for 1 hour in A and R. After sintering, leave to cool.

For the above sample, 1I(c, Br, (BH) m
ax was measured, and the results for representative samples are shown in Tables 1 and 2. Also, 1'i in Tables 1 and 2
``6 doesn't give a numerical value, but it shows the rest.

In addition, Fe -8B -15Nd -a
As a four-element system of M (X = 0%), the influence of M on Br on the Fe-B-R ternary system base is a-0 to 14.
Experiments were conducted on the range of

The results are shown in Figures 1-3.

Furthermore, in the same manner, the influence of X on Br on the base of the Pe-BRM quaternary system (A and l are used as M) was investigated, and the results are shown in FIG.

Table 1 Table 2 Table 4
・e)

[Brief explanation of the drawing]

1 to 3 are graphs showing the relationship between the content of the additive element M and Br, and FIGS. 4 to 8 are graphs showing the relationship between the content of the minor element X and Br. Applicant Sumitomo Special Metals Co., Ltd. Agent Patent Attorney Asamichi Kato Figure 5 Nd15 Fe 76.5-b Bs Nb0.5 X
bb original + white half (%) Fig. 6 Nd + 5Fe7s, 5-b B8 MOo, 5 Xbb
Fusato Mijiro 7 and a half minutes (%)

Claims (1)

[Claims] In terms of atomic percentage, 8 to 30% of R (where R is at least one rare earth element including Y), 2 to 28% of B, and one or two of the predetermined additive elements M. (However, the additive elements M in the specified proportions are: Ti 4.5% or less, Ni 8.0% or less, Bi
5% or less, V9.5% or less, Nl) 12.5% or less, 'ra 10.5% or less, Or 8.5% or less, Mo
9.5% or less, W 9.5% or less, Mn 8.0% or less1. J 9.5% or less, 81) 2.5% or less,
Ge 7% or less, Sn 3.5% or less, Zr 5.5
% or less and T- (refers to f 5.5% or less), one or more types of minor elements Below, C!
4.0% or less and P3.5% or less), however, M
The total amount of and X is M contained. A magnetically anisotropic sintered permanent magnet consisting of an atomic percentage or less of the maximum value of each element of X, and the remainder being Fe and impurities unavoidable during manufacturing.