JPS5823404A - Rare earth cobalt permanent magnet - Google Patents

Abstract

PURPOSE:To further promote columnar crystallization of alloy ingot and to try the high performance of a resin, metal, or ceramic coupling Sm2Co17 type permanent magnet by a method wherein carbon C and S, Se, Te, Ce, Pb, Cd, Bi, Si or the like are compounded and added to an Sm-Co-Cu-Fe-Hf alloy. CONSTITUTION:Concerning a precipitation hardened type permanet magnet used Sm2Co17 type crystal, when Sm-Co-Cu-Fe-Hf-C-M (M is at least one kind or more out of S, Se, Te, Ce, Pb, Cd, Bi, Si) alloy is dissolved and casted, casting macro structure of this alloy is crystallized in columnar shape as much as possible by the effect of carbon C and this particular element M and thermal treatment for magetic hardening is applied to the alloy having much columnar crystallization. After that, pulverization, magnetic field formation are done to intensity coupling by binder. When the composition of this alloy is represented as Sm (Co1-u-v-w-x-yCuuFevHfwCxMy)z by the composition formula used atomic ratio, the range of composition is 0<u<0.2, 0<v<0.5, 0<w<=0.05, 0<x<0.05, 0<y< 0.1, 6.5<=z<=9.0.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tn2 precipitation hardening type stone using 5m1colf type crystals.
m -Co -Cs -F a-Hf -C-M (
Mke &B#'# a ding a m Cd e Pb
Indicates at least one type of @Cd*BS*a4. This notation will be followed below. ) When melting and casting an alloy, the effects of carbon C and the special element M are used to transform the cast macrostructure of the alloy into columnar crystals as much as possible, and heat-treat alloys with many columnar crystals for magnetic hardening. ^, then.

Grinding, am551. This relates to permanent magnets that are shaped and strengthened by a binder.

The object of the present invention is am-C6-CB-F g-■/-
In order to improve the magnetic performance of the C-M alloy, the casting structure of the alloy ingot should be made into as many columnar crystals as possible.

We #i, 8 Soji C in patent application No. 55-3226.

-C--1-- It has been accepted that if the ingot of 1 alloy in the zr system is made into a columnar crystal, the magnetic performance of a t-magnet using this alloy will be much better than that of a bi-equiaxed crystal or a chill crystal. The present invention Fi, the fact is s m-c.

This shows that similar effects can be obtained by adding carbon C and special elements to -c, -y, -H/based alloys to increase the columnar structure.・This invention The ingot mass is subjected to heat treatment, crushed, mixed with a binder, and shaped in a magnetic field.

Manufacture magnets by bonding and strengthening binders - Extremely effective in improving the performance of resin, metal, or ceramic bonded stone. In other words, the process S before crushing is the same as that of a cast magnet, and the crystalline state of the cast ingot is used as is, so the columnar crystals that provide excellent magnetic properties as described above are added to the cast ingot in a small amount of carbon. C and special element M
Based on this effect, it is possible to make a high-performance magnetic hakama by using as much raw material as possible.

When molten metal is injected from the crucible into the mold,
Solidification begins from the mold. This is because crystal buds in contact with a solid substance have a smaller energy barrier to stable nucleation [K] than those floating in molten acid without contact. It is explained. Released raw in casting 11
Crystals grow in the molten metal while competing with neighboring crystals.The competition S* region of crystals in the outermost layer of the ingot, as shown in Figure 1, will be referred to as the chill layer. Crystals have anisotropy in length, velocity, and density, and crystals whose direction of maximum growth rate is parallel to the direction of heat flow preferentially grow by suppressing adjacent crystal division lengths. During the base length of the crystal, the closer the preferential orientation is to the heat flow, the longer it lives and remains, and as a result of being weeded out, the number of crystals (K) decreases inside the ingot, and columnar crystal bands are formed. When the conditions are right, the columnar crystal bands collide and solidification is completed, but 1 Normally, isocycle islands grow inside the columnar crystals, as shown in Figure 1. Regarding the cause of the production of isocycle islands, we have previously explained is L〈
Although it was not known, now crystals released from the casting wall or the cooled surface of the molten metal become liberated and become free crystals.

It is clear that this free crystal contradicts the isometric island body (Mu, Ohm@#te, Motagi and H
lBoda:Trasa, XBXl, 11 (19
71) 18).

8-Ken-C (1-Cs -? a-1f -C-M system 7
Magnets using original alloys are called it, ta hardening type, and some v' are called two-phase separation type magnets. This is to precipitate a different phase in the matrix and harden it with a-air.The 0-piece magnet was initially made of an am-GO-C% ternary alloy, mainly 8f
llCO1? Ever since it was first made into a magnet by using crystals, it has been widely developed.

By replacing C, with 1#, the saturation magnetization 4π up to a certain amount
It is known that X# increases. In the range where 4πI# increases, the crystal exhibits uniaxial island orientation because ti
tns(Cal-zIPmta)l? It is shown as.

1 is in the range of O-0.6. This fact 1jcoKct
It doesn't change even if you replace a certain amount of Bs@(C.

0M C) tyK-Furthermore, when Kll/ is added, the same as above of the magnetic performance can be measured even if the position of ii/ is small.

In other words, when II/ is added, even if the amount of am is small, the amount of iron is large (%), and a sufficient coercive force (Hc) can be obtained as a practical stone, making it possible to create a magnet with a high energy product. It's now possible.

As mentioned above, in this alloy, it has been revealed that among the chill crystal zone, columnar crystal zone, and equicyclic island zone, the columnar crystal zone has an excellent Ki# for making a magnet. In addition, a small amount of carbon C and a special grader is added to the alloy.

It is argued that ingots with increased columnar crystal zones are superior to ingots cast under the same conditions.

An example will now be explained using a resin bonded rare earth cobalt magnet. This magnet is made from a magnetic alloy using the method shown in Figure 2. The manufacturing method is exactly the same.

When magnets are made of equicyclic alloy, columnar crystal alloy, and chill crystal alloy, the columnar crystal alloy has a saturation magnetization of 4πXa and a coercive force (Ha
*It was found that all performances, such as bHa and the squareness of the hysteresis loop, were excellent. On the contrary, uniaxial crystal alloys and chill crystal alloys are inferior in performance. In addition, in the ingot cast under the same conditions, the columnar crystal zone was increased by adding small amounts of carbon C and special elements, and the Nagomi ingot with addition of disaster C and special elements M was found to have charcoal The performance is better in t4, in which the special element M is added to increase the columnar crystal zone.

Columnar crystal alloy #:r, since the crystals are aligned, the orientation in the uniaxial direction is improved when it is made into a magnet. tt, the alloy #'i
It is thought that the precipitates formed during the heat treatment are more uniform than those of other types.For this reason, the squareness of the heptastesis is improved.Also, the crystal structure and morphology of the precipitates are also different compared to those of Tomowajima. (It is thought that the bottom is shaped in a direction that increases Ha well.

For this reason, in order to obtain a good magnet, it is important to manufacture a single alloy in such a way that the crystals near the casting wall are made into columnar chill crystals, and the other parts are made into columnar crystals. Since the amount of chill crystal bands is small in the whole alloy, what is important in terms of manufacturing is to increase the ratio of the monoaxed bands to the anti-pillar crystal bands. From this fact, 8fi-co-Cs-Fg-Hf alloy,
C and 8.81. τ-# Ca e 1? h a Cd
a B, B, 11 (etc., etc.) are added in small amounts for casting.K, oxides, nitrides, etc. that promote the nucleation of crystallization from the melt are wrapped in carbides, sulfides, etc., and the nucleation is prevented. Activating carbon C8 special element ゛M and oxygen in the melt,
Nitrogen, etc. combine to reduce the generation of oxides and nitrides, which form the core of crystallization, and to suppress the formation of uniaxial crystals as much as possible.In this case, depending on the added element, the effect is not necessarily Although they are not equivalent, they play the same role in promoting columnar crystals.

For metals, columnar crystallization is expected to have the most effect #i, a metal formula using a textured metal element ratio, B fl
& (Cal % -9%II $CII
When expressed as IM'F@l]Jyo7w CZ MY)g.

0<co<0.3 0<V<0.1 Oku1≦0.05 0(1(0,05 0<0.1 5.0≦gri9. .

It was confirmed that Also, in order to obtain a high-performance magnet, I prefer 1 type i@Takumi range #i.

0 < s <: 0.2 o<y<o, s Q (W(0,05 0<X< 0.05 0 < Y < 0.1 6.5≦2≦9.0. , is the same as the group area shown in the claims. Therefore, the division and metal area are limited to d or less and 21!
I will explain why.

In the present alloy system 1 and its assembly area, the Bm-C system is the basis. It is added to obtain coercive force in the Cs-5Cost III alloy, and adding 0% improves 1Tia. However, 4πX# decreases. Therefore, it can be used as a practical magnetic material.

8 m (Cal - m Csm) The limit i of the Z medium basket is 0.2 m. The value of 2 is 5 < Z (
When it is between 8 and 5, 5s-C (1 alloy is !1fi
It separates into c@, type compound and BtxB co, ma compound. What is 4πXa?

8i110O1y is 20 times more expensive. Therefore, high dtX
In order to achieve H, ZFi 6.5 or higher is desirable.

On the other hand, if 2 becomes 9.0 or more, the tea value will decrease steadily and a large amount of Go-7 phase will come out, which will impair the squareness of the hysteresis loop, which is not preferable. II/#: significantly lowers the 4π work 1 of the alloy, so if 0.05 or more is added, there is no point in increasing 1- and reducing CI& to increase 4xXa.

As cq increases, 4π engineering a, i Hc decreases, so taking this limit into consideration, the upper limit is set as O, OS, and Kasumi Yu M has slightly different effects depending on the added element, but when it exceeds a certain amount, 4KX a a % Ha decreases.

Taking this limit into consideration, the upper limit was set at 0.1; however, these values are based on the total amount of the composite addition, and the ratio is not particularly specified.

The binder is a variety of polymers such as epoxy, phenol, rubber, polyester, etc. or a metal binder, preferably a low M point alloy with a melting point of 400° C. or lower.

The present invention will be described below according to examples. Example 1 After casting a m (Co0.59 Cs0.07 I'g
O,3Hlo,0I C0,0280,(11) 8.
Mix 15 raw materials to make metal 2.

Alloys of I KP in total were melted in a high frequency furnace in a murium gas atmosphere and cast into an iron mold as shown in FIG. 3 at a hot water temperature of 1550°C. The molten metal was cooled mainly from the side walls, and had the structure shown in FIG. Figure 1E1 shows the structure when the ingot is cut at the center. In these areas, remove the chill layer.

C is a columnar structure and an equiaxed structure. Cast ingots of parts M, B, and C of the alloy ingot were cut out, and resin-bonded limestone was produced according to manufacturing method 1 shown in FIG.

Solution treatment is 1150℃ for 24 hours, m is 80℃.
The test was carried out at 0° C. for 20 hours in an argon atmosphere. An epoxy resin of 1.8 wK as a binder was kneaded into a magnetic fine powder that had been ground into average particles (10 μm) using a ball mill method. This kneaded mixture was pressed into an original shape in a 16K Gai field.

Appropriate heat is applied to the bottom body to harden the resin (cure treatment).
), a stone was charged. The results are shown in Table H1. As can be seen, the columnar crystal zone in part B has the M1 performance of 0.
Part of the Torowa Shima Belt L got something from Niji.

Very good A. Although it can be said that the chill crystal band in part A is lower than that in part B, it is superior to part 0.

Table 1 shows the squareness of the hBQJ-u hysteresis loop.

BQ=Hk/iHe, which is given by Hk#'i, is the magnitude of the magnetic field given by 0.9 Bde on the 4KX-H1cffi curve. As a result, it is clear that the columnar crystal portion of the LLB portion has the best performance. Chilled crystal band in part A.

Since the insects are removed only in the vicinity of the casting wall, and the amount of insects in the whole ingot is small, placing the insects on top of the ingot manufacturing is also important because it will suppress the growth of isocycle islands and develop columnar crystals. be. Note that part A used in this example contains A
Considering the situation in the department.

It is thought that part of the columnar crystal B of a certain degree is included.

Example 2 A resin-bonded magnet was manufactured from the bottom alloy shown in m2H in a similar manner to Example 1. However, solution treatment is 1
The test was carried out at the most suitable temperature between 120 and 1180°C for 20 hours.

wKz Table This was carried out on the ingots of Sections ij, B, and C of this example. The results are shown in Figure 4. Even if the amount of 1- increases, columnar crystal zone B provides better magnetic performance. Even if the amount of F- is increased to some extent.

It became clear that a certain degree of concealment (Ha) could be obtained.Example 3 A resin-bonded magnet was manufactured from the alloy of Group J in Table 3 in exactly the same manner as in Example 2.The results are shown in Figure 5. Show: 8gl
(For C6 (s F# Hf CM) 17 type alloy,
When the amount of 0% decreases, (Ha decreases, but Vi in the columnar crystal, compared to the one in the
It can be seen that a value 6 orders of magnitude higher is obtained.

In addition, the columnar crystal portion has better squareness.

Table 3 Example 4 Using exactly the same method as in Example 2, a resin-bonded magnet was manufactured from the bottom alloy shown in Table 7. . The water temperature during alloy casting is 160
It is 0°C. The cast ingot has an L-shaped cross-sectional macrostructure as shown in Figure H1. The ratio of the columnar structure of B was approximately 60 in Alloy 1, 80 to 89 in Alloys 42 to 4, and 70 to 78 in Alloy 5 to 6. The proportion of columnar structure was estimated by observing the cross section of the ingot under a microscope and using the mesh method.

114 Table As can be seen from the IK5 table, the results are shown in 5@.

The one with the most columnar structure has the best magnetic performance. This 15 to 1 alloy set is C and " + 81 @ τa
, ca, X”k, cd, BiaBi etc. t) Special yc element M
It can be seen that the above-mentioned -6X of Kzb and a-air performance is affected by adding Kzb and a to promote the columnar structure as much as possible.

Iris 5jl+ Example 5 6th! A resin-bonded magnet was manufactured using the alloy having the composition shown in 1 in exactly the same manner as in Example 2. The results are shown in Table 7.

Table 6 No. 7I! It was possible to obtain a magnet having sufficient thermal performance even when the above values were changed.

This 19km am-Go-Cm-Fg-H/alloy carbon 8'To' * 8#s Ta a Cl
a P 6 # Cde B% 68% xl) further promotes the columnar crystallization of the alloy ingot and improves the Btl of resin, metal, or ceramic bonds.
High-performance magnet #f of the present invention, in which the performance of LxCoylJfB stone has been improved.

Time creation step motor, micro speaker.

Coreless motors and air sensor nuts have a wide range of industrial uses.

[Brief explanation of drawings]

Figure III: #'11 This is a cross-section of the ingot cast into the mold, cut longitudinally through the center. B, C1 indicate the chill layer, columnar layer, and equiaxial layer, respectively. This is a cross section of the Fuha mold. FIG. 2 Fi shows the manufacturing process of the resin-bonded magnet. Figure 3 #-1. Showing an iron mold. All wall thicknesses are 15U. The unit of length is Fiwx. Figure 4 ij, Bm (Can, 89 V CsO,
07Pg V HfO, QICo, 02 Bo, 01)
8.1 Group 11a'4C: MLnte, v to i 1kt
The magnetic performance of the resin-bonded magnet is shown below. Figure 5 ij, am(Co0.73-s Cs s F
gO, 22Hlo, 02G0.02 Bo, 01)8.
In group 3 ff, the magnetic performance of the resin bonded magnet is shown when the deafness is changed. Applicant Suwa Seikosha Co., Ltd. Agent Mr. Mogami Figure 1 Figure 2 Figure 2 $ Hikuri g, ld+ (7-/6

Claims (1)

[Claims] Samarium (8fi), cobalt (Co), copper (0%
), iron (Fs) #/%-yniuA (H/),
Charcoal
8#) #Tellurium (T#), Cerium ((4), Lead ('6), Cadmium (Cd), #Bismuth (B4)
, at least one kind of silicon (84)], whose 1ily is an assembly formula using atomic ratio. am(--9b-V-W-X-'IC% w 'I!e
V HfW OX MY) When expressed as g, the range of one assembly is. Bm@ where 0<%<0.2 o<v<o, so<Y ri0.05 o<x<o, os O<Y<0.1 6-5<Z<9.0 A Kobarujima permanent stone alloy which is characterized by being an alloy mainly composed of C (jy type crystals, and in which the macrostructure of the ingot at the time of casting is mainly a columnar structure.