JPS60214505A - Manufacture of metallic bonding type magnet - Google Patents

Abstract

PURPOSE:To improve the magnetic performance and heat-resistance by a method wherein the rare earth intermetallic compound powder is mixed with the metallic alloy and is formed by pressurized extrusion within the magnetic field while heating in the mold. CONSTITUTION:The rare earth intermetallic compound powder such as SmCo5, Sm(Co 0.8 Cu 0.2)5, Ce(Co 0.8 Cu 0.8 Cu 0.2)5, etc. is treated with heat for magnetic hardening. After that, is powdered, next the alloy magnetic powder is mixed or plated with the metallic bonding material. These metal alloy are Pb, Sn, In, Bi, Cd, Al, Cu, Zn, solder, Woods' metal alloy, cupper alloy, various soldering alloy, etc. The melting point of the metallic bonding material is 200- 900 deg.C and desirably at about 250-600 deg.C. Then, the metallic bond type magnet 19 is provided by solidified under cooling and affording anisotropic property by means that the mixture 14 of the magnetic powder and the metallic bonding material is passed though the die 13 under 600 deg.C and under 30kOe of the magnetic field.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for manufacturing a permanent magnet in which rare earth intermetallic compound powder is manufactured by a metal bonding method.

[Prior art]

Conventionally, a method for producing a composite magnetic material using a metal bonding method of rare earth metal compound powder was disclosed in Japanese Patent Laid-Open No. 48-66.
No. 524 is known. This conventional method uses rare earth metal compound powder and Sn (tin).

A preform is made by mixing Pb (lead) and solder alloy powder and compression molding the mixture at room temperature in a magnetic field. The molded product is placed in a heating furnace at 100°C to 400”C to melt the low melting point metal of the binder, and then cooled and solidified, or heated,
A method is adopted in which the material is compressed and then cooled.

The metal-bonded magnet produced in this way had the following drawbacks.

(1) Low magnetic properties”・-(B H) max,
5 M G Oe or less.

(2) Mass production efficiency is low, and its practical value as an industrial material is low.

(8) Heat resistance is low at 150°C.

〔the purpose〕

The present invention is intended to solve these problems, and its purpose is to improve the magnetic performance of metal-bonded rare earth intermetallic compound magnets and to create permanent magnets with high cost performance that can be put to practical use as industrial materials. It's there to provide.

〔overview〕

The object of the present invention is rare earth intermetallic compounds.

For example, the composition of the alloy can be expressed as the following general formula: S m Oo6, S m'(ooo, a
It is a so-called 1-5 rare earth intermetallic compound alloy such as Quo, 2)5,0s (Ooo, aauo2)s.

Also, am(Oo Ou Fezr)y,s Smo,
a Yo, 2 (000u T6)? ,2, Sm(O
o Ou He T1)7.2 Smo, s PrO,
2 (Oo Ouu?e Zr) y, s, etc. 2-17
It is a rare earth intermetallic compound alloy. The alloy is usually compressed in an Ar gas arc furnace or an Ar gas low frequency melting furnace to produce an alloy. Next, there are 2-17 alloys, which are made into powder after heat treatment for magnetic hardening, and 1-5 alloys, which are made into powder by immediately pulverizing the alloy.

As for the method of preparing the powder, the 1-5 series uses a jet mill method or a ball mill method in order to obtain a single magnetic domain particle size of 3-5 μm.

For the 2-17 series, the powder particle size is not selected, so it is 2μ.
The range is from m to 500μ.

The alloy magnet powder is then mixed or plated with a metal binder. Metals and alloys include the following: Fb (lead)t
Sn (tin), In (indium) uBi (bismuth)
, Oa (cadmium).

Examples include At (aluminum), Ou (copper), IZn (zinc), solder, wood alloy, copper alloy, and various brazing alloys.

If the ratio of the magnet powder to the metal binder is preferably 60% to 90% by volume of the magnet powder, extrusion molding while heating is possible. The melting point of the metal binding material is 2
00°C to 900°C9, preferably around 250 to 600°C. If the temperature is too high, hot extrusion molding in a magnetic field will
This is because the molding pressure becomes high, making it difficult to manufacture a magnet with a desired shape. On the other hand, if the temperature falls below 250° C., the heat resistance of the magnetic performance of the magnet deteriorates.

The heating range is up to the die part and the extrusion barrel (cylindrical part). An orienting magnetic field of magnet powder is applied to the die from the outside. The magnetic field strength is 1 at the die nozzle part through which the mixture passes.
0KOa to 25KOa is necessary. The magnetic fields are D, O,
Combinations of pulse, alternating current, etc. can also be adopted as needed.

[Comparative example]

FIG. 1 shows an example of a conventional method of pressing a metal-bonded rare earth intermetallic compound magnet in a magnetic field.

Kempo is upper ram 1. The coil 4 is attached to and fixed via a mounting plate 2.5. Similarly, a coil is placed at the bottom of the press. The molds 5, 6, 7.8 are set in this gap via the pole piece 4-α. Upper bunch 5.
The lower punch 7 is made of ferromagnetic SUJ 2 material and a mixture of magnet powder and metal bonding material is placed between the gaps 8. The mold was energized between the upper and lower coils, and compression molding was performed at room temperature of 24° C. while applying a direct current (D, 0) magnetic field of 8 to 12 KOe.

As the magnet powder, an alloy having a composition of SSm0o was used, and the particle size was usually 3 μt to 8 μ, with an average particle size of 4.6 μ. This powder was produced in a Ni gas atmosphere by jet milling. As the metal bonding material, sm-pb solder alloy powder was used. arA4Fa・powder, s n-v-ouz
A comparative sample was prepared by mixing the remaining No. 2 powder and molded according to the method described above. The shape of the sample is φ15×10
t%, there is anisotropy in the axial direction.

The sample after compression molding was placed in an oven heated to 250°C and baked.

The characteristics of the conventional sample prepared in this manner were as follows.

(Magnetic properties) (Mechanical properties) Coercive pressure -20ff//swf Transverse rupture force -8t/- Hardness - Hv210 [Example-1] Approximately 21% of the composition alloy shown in Table 1 was made in a low compression melting furnace. Ta.

Table 1 The composition alloy shown in Table 1 is E-1, which is a 1-5 system, and the coercive force mechanism is due to the rotation of single-domain particles, so the pulverization process that is performed as is is A magnetic powder was produced with an average particle size distribution of about 3-5 microns. l-2~]In-6 is 2
-17 series, and was subjected to magnetic hardening heat treatment. (See Table 1) Next, each sample was coarsely crushed in a show crusher and finely crushed in a ball mill. The particle size of the powder obtained at this time was within the range of 3 μm to 150 μm.

The powders were each subjected to surface treatment under the conditions shown in Table 2. First, in order to improve the wettability with the metal binding material, 100 f of powder of electroless copper metal sample Nα was subjected to electroless O plating for about 5 minutes in a plating bath. The plating thickness on the powder surface at this time was about 1oooX to 5oooX. The powder was then dried and mixed with Sn powder.

Sn (tin) powder has a particle size of 5 to 20μ.
Added 1% and mixed well. Approximately 20 f of each mixture was charged into a hot magnetic extruder shown in FIG. FIG. 2 shows a hot magnetic field extrusion molding apparatus in one embodiment of the metal-bonded magnet according to the present invention. 10 is a pressurizing punch,
It is made of 5ffS310 heat-resistant steel. The cylindrical container 11 is heated by a micrometer heater 12, and the same material as the punch 10 is used because it needs to be heat resistant and non-magnetic. Reference numeral 14 denotes a sample that has been put in. When the heating temperature reaches about 380° C., the Sn added as a metal binder in the mixed powder 14 begins to melt and wets well with the magnet powder. Here, since the surface of the magnet powder has a copper plating layer in advance, the mixed Sn powder wets well with the magnet powder. The dice 13 applies direct current to the magnetic field coil 16 and pole piece 15,
A magnetic field was generated between the pole pieces. A magnetic field of approximately 12 KOe was generated in the gap portion 17 of the die 13. 1
The magnets were extruded in a magnetic field by applying a pressure of about 100,051 mm to a punch of 0, and then solidified by natural air cooling in a support stand of 20 to produce 19 metal-bonded rare earth permanent magnets. A plan view of the die 13A-A' is shown in FIG.

13-α is the die side plate, which has been tempered with 5UJ-2, a strong emissive material, and has a Ht of 650±30. 13-6 is non-magnetic stellite. Next, Table 2 shows the magnetic properties 9 and mechanical properties of the samples produced by the method of the present invention.

It was found that both magnetic properties 1 and mechanical properties were further improved compared to the comparative example in Table 2.

[Example-2] Comparative example sample and Example 1 sample Ham-1 sample were processed to φ
Machined to 10X10t% (ro-1). Eleven samples were prepared for each. Next, a pulsed magnetic field of 40 K Oe' was applied to fully magnetize, and the initial 7 lux Φ0 was measured using a flux meter. Next, after maintaining the heating temperature for 30 minutes each, and cooling to room temperature, the flux ΦT was measured and its rate of change was investigated.

Figure 4 shows the demagnetization rate. In the comparative example, when the temperature exceeds 140°C, the rate of change in magnetic flux Φ (irreversible demagnetization) tends to increase.
Its heat-resistant use limit is around 140°C. On the other hand, it was found that the method of the present invention has heat resistance up to around 180-200°C.

[Example-3] Sample N [Ll-2 composition alloy powder of Example 1 was used to perform extrusion in a hot magnetic field. The manufacturing conditions at that time are shown in the third page.

The magnetic field extrusion device was used in the same manner as shown in FIG.

Table 4 shows the properties of the obtained samples.

According to this example, the metal-bonded rare earth intermetallic compound magnet produced by extrusion had excellent characteristics that were not available in the past.

Among the mechanical properties, the transverse rupture strength was as high as 106/-, and the hardness was around Hv 300, indicating high toughness.

As mentioned above, in the present Tatemei method, as a surface treatment of the rare earth intermetallic powder and the magnet powder, mixing it with a metal alloy,
It is made by pressure extrusion molding in a magnetic field while heating in a mold, which greatly improves magnetic performance and heat resistance to 18%.
It is possible to provide industrial materials that can be mass-produced at temperatures of 0°C to 200°C.

[Brief explanation of drawings]

Figure 1 shows a conventional magnetic field pressure molding device. 1... Press pressure piston 2.3... Coil fixing frame 4... Electromagnetic coil 4-α... Electromagnetic pole piece 5...・
Mold upper punch 6...Mold diamond...Mold lower punch 8...Magnetic powder 9...Flow of magnetic lines of force Figure 2 shows the method of the present invention FIG. 2 is a sectional view of a vertical magnetic field extrusion molding apparatus in FIG. 10... Pressure punch 11... Die 12... Heater 13... Molding die 14... Magnet powder 15... - Electromagnet pole piece 16... Electromagnetic coil 17... Nozzle 18... Direction of magnetic field orientation 19... Extruded metal bonded magnet 20.
. . . Dice support frame 21 . . . Dice holder is a stand FIG. 6 is a sectional view taken along the line AA′ in FIG. 2 in the present invention. 13-α... The magnetic pole part of the die is made of 5UJ2 material. 13-b... The non-magnetic stellite is in the die side part. Figure 4 shows the heat resistance of the ° magnet of Example 2. The graph shows the heating temperature and irreversible demagnetization rate of the sample. Applicant Suwa Seikosha Co., Ltd. Agent Patent Attorney Mogami Tsutomu No. 1-Figure 77h Jukui Cliff (.)

Claims (1)

[Claims] Rare earth intermetallic compound magnet powder and melting point between 200℃ and 900℃
℃ or less, a mixture consisting of metals at a temperature of 600℃ or less,
A method for manufacturing a metal-bonded magnet, characterized in that the magnetic field is passed through a die of 50 KOe or less to provide anisotropy, and the magnet is cooled and solidified.