JPH0228901A - Manufacture of polymer composite rare earth magnet - Google Patents

Abstract

PURPOSE:To improve the performance of a polymer composite rate earth magnet by a method wherein powder particles of sintered powder formed by finely pulverizing a sintered material made of R2T14B alloy ingot powder and having predetermined particle sizes are replaced with quenched alloy powder manufactured by processing a R2T14B alloy ingot by a liquid quenching method. CONSTITUTION:In a manufacture of a polymer composite magnet from R2T14B alloy powder containing as main ingredients Nd, Fe, B by using polymer resin, powder particles of sintered powder made by finely pulverizing a sintered material made of R2T14B alloy ingot powder and having 30mum or less of particle size as R2T14B alloy powder is replaced with quenched alloy powder manufactured from R2T14B alloy ingot by a liquid quenching method. Powder molded piece obtained by molding the powder in a magnetic field is sintered as a sintered material having high crystalline orientation, powder so prepared as to contain the R2T14B alloy powder manufactured by the liquid quenching method in a range of particle sizes of 30mum or less in the sintered powder pulverized powder is used to provide high magnet characteristics.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a polymer composite magnet, typically a so-called rubber magnet, and in particular to a method for manufacturing a polymer composite magnet, typically a so-called rubber magnet. The present invention relates to the improvement of a polymer composite rare earth magnet using R2T14B rare earth magnet powder whose main components are (R), a transition metal (T), and boron (B).

[Conventional technology]

A polymer composite magnet is one in which magnet powder is dispersed in a polymer resin, or one in which magnet powder is bound with a polymer resin. This magnet has various advantages not found in cast magnets, sintered magnets, etc., such as elasticity and ease of processing, and is used in various fields. however,
Because they are made of magnet powder and non-magnetic resin, they have the disadvantage of having lower magnetic properties than sintered magnets and the like.

Therefore, various types of magnet powder have been used to achieve zero dispersion and bonding in an attempt to achieve high magnetic properties by making the powder anisotropic, such as by orienting it in a magnetic field. In the present invention, R2T14B, which is represented by the Nd-Fe-B system, which currently exhibits the highest magnetic properties.
Uses magnet powder.

Conventional polymer composite magnets using rare earth magnet powder are manufactured by melting the raw materials, heat-treating the resulting alloy ingot, pulverizing it, mixing the powder with polymer resin, and molding it in a magnetic field. Ta. The magnet alloy powder used here was desirably composed of fine single-crystal particles in order to improve crystal orientation in a magnetic field.

[Problem to be solved by the invention]

However, R2 represented by Nd-Fe-B magnets
In T14B alloys, the coercive force (1Ho) decreases due to mechanical stress during crushing, so in fine regions where the powder is composed of single crystal particles, the coercive force (1Ho) decreases significantly.
was decreasing. Therefore, in a manufacturing method using a molten ingot as a starting material, even if a sintered magnet with a high IHC is crushed and used as magnet powder, the result is a polymer composite magnet that exhibits extremely poor magnetic properties.

Moreover, in the method of manufacturing a polymer composite magnet by heat-treating an ingot and then pulverizing it to produce a polymer composite magnet, the magnet exhibits extremely poor magnetic properties that are worthless.

On the other hand, R-
As a method for producing a T-B magnetic alloy, a liquid quenching method has been known in which a molten alloy is injected onto a rotating roll or the like and then super-quenched to obtain a magnetic alloy.

However, the powder obtained by this manufacturing method could not achieve anisotropy. Subsequently, it was found that a magnetic powder capable of being anisotropic was obtained by hot plastic working this liquid quenched alloy. Since this method requires high temperature and high pressure, the equipment is expensive and large-scale, and there are concerns about stabilizing the properties in the manufacturing state. is still difficult to obtain, and it is difficult to say that it is industrially useful.

The technical problem of the present invention is to provide a method for manufacturing a high-performance anisotropic polymer composite magnet by utilizing a commonly practiced manufacturing process for R/T-B sintered magnets. Therefore, it is an industrially very useful manufacturing method.

[Means to solve the problem]

According to the present invention, R 2 T 14 B (where R is Y and a rare earth element, and T is a transition metal) alloy powder containing Nd, Fe, and B as main components is made into a polymer composite using a polymer resin. In the method of manufacturing a type magnet, the R2T1
As the 4B alloy powder, powder particles with a particle size of 30 μm or less of the sintered body powder obtained by finely pulverizing the sintered body produced from the R2T 14B alloy ingot are quenched using the liquid quenching method from the R2T 14B alloy ingot. A method for manufacturing a polymer composite rare earth magnet characterized in that the magnet is made of a magnet substituted with alloy powder is obtained.

Here, in the present invention, the method of manufacturing a polymer composite magnet using a polymer resin is a method of mixing raw material alloy powder with a polymer resin and performing injection molding, extrusion molding, or compression molding, or A method of impregnating polymer resin after compression molding.

That is, the present invention involves pulverizing an alloy ingot obtained by melting, sintering the resulting powder compact by compacting it in a magnetic field to form a sintered body with a high degree of crystal orientation, and then After pulverizing the sintered body, by using powder adjusted to contain R 2 T 14 B alloy powder produced by the liquid quenching method in the particle size range of 30 μm or less in the sintered body pulverized powder, a high magnet can be obtained. This is to realize an R-T-B polymer composite magnet having the following characteristics.

The orientation of the magnetic properties of the present invention is related to the improvement of the squareness of Ho, Br and demagnetization curves of the sintered powder by heat treatment, and this effect is due to the fact that the molding powder has a plurality of oriented crystals. This is deeply due to the fact that it is composed of grains. However, the improvement in magnetic properties due to heat treatment of this powder tends to decrease as the powder particle size becomes smaller.

As a result of various experiments carried out by the present inventors, it has been found that it is clearly difficult to recover particles of 30 μm or less from the damage caused by crushing even by heat treatment, even in sintered powder.
In the following range, the R/T-B type high-grade alloy powder, which has high magnetic properties, contains liquid quenched alloy powder produced by liquid quenching method or alloy powder obtained by hot plastic working of liquid quenched alloy. We discovered that a molecular composite magnet can be obtained.

In the present invention, most of the powder for polymer magnets can be manufactured using a manufacturing process for sintered magnets that have high characteristics, can be processed in large quantities, and exhibit magnetic characteristics with little variation.
It will be very beneficial.

The reason why the R2T14B alloy powder, which is not produced by the liquid quenching method, is specified to be included in the particle range of 30 μm in the sintered compact powder is that the effect of inclusion is saturated in the range of 30 μm or more and is not clear, and the particle size is 30 μm or less. This is because the effect becomes remarkable when the range is set to .

The present invention provides a powder that can be applied to a wide range of manufacturing methods for polymer composite magnets, such as impregnation molding, compression molding, and injection molding. Moreover, since a high-performance polymer composite magnet can be easily realized, it is very useful industrially.

Examples will be described below.

Example 1: Nd with a purity of 97 wt% (the remainder is other rare earth elements mainly consisting of Ce and Pr), Dy with a purity of 99 wt% or more, ferroboron (B purity about 20 wt%), and electrolysis Using iron (
Nd-Dy) is 34.00.90.
An ingot having a composition of 1 wt% B, 1.0 wt% B, and the balance Fe was melted by high frequency heating in an argon atmosphere to obtain an alloy ingot.

Next, this ingot was coarsely ground, and then finely ground to an average particle size of about 2 μm using a ball mill.

This alloy powder was heated at a rate of 1 ton/in a magnetic field of about 20 kOe.
This molded body, which was molded into a rectangular parallelepiped shape under a pressure of -, was held in vacuum at 1000° C. for 1 hour and then held in Ar for 3 hours to obtain a sintered body. This sintered body is 7.55gr/cm3
The average crystal grain size was about 5 μm. A part of this was aged at 600°C for 2 hours and its magnetic properties were measured, and the result was Br12.8kG.

IHc20kOe, (BH) lax, 39H,
It was about G, Oe.

The sintered body that was not subjected to aging treatment was coarsely pulverized to a particle size of 300 μm or less, and then the powder was held at 600° C. in vacuum for 1 hour and in Ar for 94 hours, and heat treated.

On the other hand, the alloy ingot was remelted by high-frequency heating in an Ar atmosphere, and then sprayed onto a Cu roll with a circumferential speed of about 4 On/sec to form liquid-quenched alloy ribbons and flakes with a thickness of about 20 μm and a width of about 3 + m. Next, this liquid quenched ribbon was coarsely pulverized, and then pulverized at 700°C and 1 ton/ton in an Ar atmosphere.
A molded article was obtained by hot pressing at a pressure of -. This density was about 7.50g/am3.6Next, this molded body was pressurized in an uniaxial direction at 700"C and 2.5tOn/- in an Ar atmosphere, and the dimension in the pressing direction was about 175gr/am3. Hot plastic working was carried out so that
It has magnetic anisotropy in the direction of pressure, and the crystal grain size is approximately 0.3μ.
It was made up of laminated plate-shaped crystals with a thickness of about 0.1 μm.

The magnetic properties of this molded body are Br12.2kG.

IHc22kOe, (Bl(>1aX, 33H,
Next, this compact was pulverized to an average particle size of about 10 μm.

Next, the fine particles in the heat-treated sintered body coarse powder were
Below, 30 μm or less, 40 μm or less.

When the particles were separated and removed in the range of 50 μm or less and the corresponding amount was supplemented with hot plastic-processed compact powder,
Approximately 5 wt% for 20 μm or less, approximately 10 wt% for 30 μm or less
wt%, about 20 wt% for 40 μm or less, and about 3 owt% for 50 czm or less.

Next, this powder was mixed with 35 VO 1% polyethylene, and then injection molded into a mold while applying a 20 koe magnetic field at about 100° C. to obtain a polymer composite magnet. The magnetic properties of the polymer composite magnet were measured by applying a magnetic field of about 30 koe, and the results are shown in Figure 1. By replacing the sintered powder of 30 μm or less with hot plasticized powder, the magnetic properties of the polymer composite magnet were improved. It has improved significantly.

For reference, the above-mentioned aging-treated sintered body also
Coarsely pulverized to 00 μm or less, mixed with polyethylene,
When a polymer-composite magnet was produced by injection molding, the magnetic properties were Br5.4kG, IHc3, 5kOe,
(BH)nax, 4.5H, G, Oe.

Example 2 Using cerium disime consisting of 5 wt% Ce, 15 wt% Pr, and the balance Nd (however, other rare earth elements were included as Nd), ferroboron, 'r4 decomposed cobalt, and aluminum, Example 1 Similarly, the rare earth element R was 32 wt% and Co was 7 wt%.

An R-T-B ingot containing 1 wt% of Aj and the balance of Fe was obtained.

Next, using this ingot, pulverization, compaction in a magnetic field, and sintering at 1040°C were performed in the same manner as in Example 1.

The sintered body obtained here has a density of about 7, 55 Or/am3
It consisted of crystals with an average grain size of about 6.5 μm.

When a part of this sintered body was aged at 600°C for 2 hours,
Br12.2kG.

IHcl 1, 5kOe, (BH)laX33
, 5M, G, Oe.

The sintered body that was not subjected to aging treatment was coarsely ground to a particle size of 500 μm or less, and then fine particles were separated and removed in the range of 20 μm or less, 30 μm or less, and 40 μm or less. The amount of separation is approximately 31t%, respectively, based on the total amount of powder.
They were about 7 wt% and about 15 wt%.

On the other hand, an alloy ingot was used and injected onto a Cu roll having a circumferential speed of about 151/513C in the same manner as in Example 1, to obtain a liquid-quenched flake with a thickness of about 50 μm and a width of about 7III. This flake was molded in the absence of a magnetic field to obtain a liquid-quenched powder flake. This thin piece was molded in no magnetic field and the magnetic properties of the powder alone were measured: 4πIs about 10kG, Br about 7, skG, , Hc about 18koe, (BH)
Ilax, about 108. Next, this liquid-quenched flake was pulverized to an average particle size of about 5 μm using a ball mill.

Next, the sintered body crushed powder from which the fine particles had been removed was supplemented with liquid quenched thin flake crushed powder in an amount corresponding to the amount removed, and mixed. This mixed powder was molded into a disk shape under a pressure of 3 tons/- in a magnetic field of about 20 kOe, and then
After this heat treatment, the sample was heated at 0° C. for 1 hour in vacuum, kept in Ar for 1 hour, and then quenched, and the density of the sample was about 6.3 Qr/am 3 .

Next, this heat-treated sample was evacuated, impregnated with epoxy resin, and then held at 100° C. for 2 hours to be cured to form a polymer composite magnet. The measurement results of the magnetic properties are shown in FIG. 2. By replacing the sintered powder of 30 μm or less with the liquid quenched powder, the magnetic properties of the polymer composite magnet were significantly improved.

For reference, regarding the above-mentioned aged powder,
After coarsely pulverizing to 300μm or less, molding in the same magnetic field, and impregnating and curing with epoxy resin, the magnetic properties as a polymer composite magnet were measured. d5.4gr/■3Br5
．． 2kG, IHc3.0kOe, (BH)n
ax.

3,5t4. It was G, Oe.

Example 3: Using Nd with a purity of 97 wt% (the remainder being other rare earth elements mainly consisting of Ce and Pr), ferroboron, and electrolytic iron,
In the same manner as in Example 1, the rare earth element (R) was 33.5w.
t%, B was 1.1 wt%, and the balance was Fe.

Next, using this ingot, pulverization, compaction in a magnetic field, and sintering at 1020°C were performed in the same manner as in Example 1.

The sintered body obtained here has a density of approximately 7.55 flr/
cm 3 and consisted of crystals with an average grain size of about 6 μm. When a part of this sintered body was aged at 600°C for 2 hours, the Br was 13.7kG.

IHcl 1, 5kOe, (BH) IIa
x, 44H, G, Oe.

The sintered body that was not subjected to aging treatment was coarsely ground to a particle size of 300 μm or less, and then the powder was held at 600° C. in vacuum for 1 hour and in Ar for 4 hours and heat treated.

Next, the m-fine particles in the heat-treated sintered coarse powder were
Thereafter, the particles were separated and removed in the range of 30 μm or less and 40 μm or less, and the corresponding amount was supplemented and mixed with the liquid quenched fine powder (pulverized particle size: about 5 μm) prepared in Example 2. The supplementary amounts are approximately 5 wt%, approximately 10 wt%, and approximately 20 wt%, respectively.
Met.

Next, 25 vol. of epoxy resin was added to this mixed powder. % and then molded into a disk shape under a molding pressure of 5 ten/- in a magnetic field of about 20 koe. This molded body was held at 100° C. for 2 hours to be cured, and a polymer composite magnet was obtained. The measurement results of the magnetic properties are shown in FIG. 3. By replacing the sintering-resistant powder of 30 μm or less with liquid quenched powder, the magnetic properties of the polymer composite magnet are clearly improved.

For reference, regarding the above-mentioned aged powder,
It was finely ground to 300 μm or less, heat treated, mixed with epoxy resin, molded in a magnetic field, and cured in the same way, and the magnetic properties were measured. Br5.5kG, IHc3.0k
Oe, (BH)laX, 4°OH,, G, Oe.

As shown in the above examples, R 2 having anisotropy
, A polymer with significantly improved magnetic properties by containing R2T14B alloy powder produced by a liquid quenching method in the particle size range of 30 μm or less in a molding powder produced by pulverizing a T i 4B sintered alloy. Composite magnets can be realized.

In the above embodiments, the Nd-Dy-Fe-B system is used.

Ce-Pr-Nd-Fe-Co-Al　-B system.

Although only the Nd-Fe-B system has been described, a portion of Nd may be replaced by Y and other rare earth elements such as Gd and Tb.

Even if a part of Fe is replaced with Ho, etc., a part of Fe is replaced with another transition metal such as Mn, Cr, Ni, etc., and a part of B is replaced with another semimetal such as SL, C, etc., one magnet can be obtained. The composition of the alloy is Nd, Fe, and B as some of the main components, and the compound system of magnets is R2, such as the Nd2Fe14B system.
If T14B contributes to magnetism, it can be easily inferred that the effects of the present invention can be fully expected.

In addition, in this example, only Evokin resin and polyethylene were described as polymer resins, but any material (for example, other polymer resins) can be used as long as it is present inside the molded product and contributes to improving the strength of the molded product. Those skilled in the art will easily understand that the scope of the present invention falls within the scope of the present invention.

Further, regarding the manufacturing method of polymer composite magnetization shown in the examples, there are an impregnation type in which a molded body is impregnated with resin, and a compression molding type in which powder and resin are mixed and then compression molded.

Although we have only described injection molds that perform injection molding after kneading powder and resin, Ike's molding method, for example, molding by extrusion 2
Those skilled in the art can easily imagine that other manufacturing methods such as molding using 0-mol can also be applied.

〔Effect of the invention〕

As explained above, according to the present invention, a method for manufacturing a high-performance anisotropic polymer composite rare earth magnet is achieved by utilizing the normally practiced manufacturing process of R-T-B sintered magnets. can be provided.

Figure 1

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between the powder particle size in the sintered compact pulverized powder substituted with the hot plastically worked compact powder in Example 1 and the magnetic properties of the polymer composite magnet. FIG. 3 is a diagram showing the relationship between the powder particle size in the sintered compact crushed powder substituted with the liquid quenched alloy powder in Example 2 and the magnetic properties of the polymer composite magnet, and FIG. FIG. 3 is a diagram showing the relationship between the powder particle size in the substituted sintered compact powder and the magnetic properties of the polymer composite magnet. Replaced powder particle size (μm) Figure 2 Replaced powder particle size (PTrL) Figure 3 Replaced powder particle size (PTrL)

Claims (1)

[Claims] 1. R_2T_ containing Nd, Fe, and B as main components
In a method for manufacturing a polymer composite magnet using a polymer resin and a 1_4B (where R is Y and a rare earth element, and T is a transition metal) alloy powder, the R_2T_1_4B alloy powder is made from an R_2T_1_4B alloy ingot powder. Particle size of sintered body powder obtained by finely pulverizing the generated sintered body is 30
A method for producing a polymer composite rare earth magnet, characterized in that powder particles of μm or less are replaced with rapidly solidified alloy powder produced from an R_2T14B alloy ingot by a liquid quenching method.