JPS58139406A - Manufacture of rare earth cobalt base permanent magnet - Google Patents

Abstract

PURPOSE:To improve the density and to make the magnetic property excellent corresponding thereto by a method wherein a permanent magnetic alloy comprising rare earth element and transition metallic element is heated, sintered, quenched for solution heat treatment and aged, to meet specified requirements. CONSTITUTION:A rare earch Co base alloy powder of R2 M17 type permanent magnet alloy comprising rare earth element R and transition metallic element M is formed. However R further comprises one or two or more combination of Y, La, Ce, Pr, Nd, Sm and mish metal while M comprises one or two or more combination of Cu, Co, Fe or Ni in addition to the combination of a part of said transition metal substituted for one or more elements such as Mn, Ti and the like. Firstly the formed body is heated from air temperature up to 800 deg.C or less per 4-20 deg.C/min in the vacuum of 1X10<-2> Torr or less. Secondly it is sintered at 1,100-1,250 deg.C in the Ar gas atmosphere of 1X10<-2> Torr. Thirdly after solution heat treatment at 1,100-1,250 deg.C, the permanent magnetic alloy is quenched at 200 deg.C/min or more and aged.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method for producing rare earth Cobal F-based permanent magnets, in which production involves heating in a vacuum atmosphere, sintering in a reduced pressure argon gas atmosphere, and solution treatment/quenching. Regarding the method.

Kidochin cobalt-based magnets have been recognized as permanent magnets with higher Yasuda force and larger two-wheel-force product compared to alnico-based magnets and ferrite-based magnets that are widely used today. Increasingly, in a wide variety of fields, including the electronics industry.
It is used in

The manufacturing method is the most important factor, and each magnet must be manufactured with strict Kw control.

Among them, rare earthen metal, which is one of the main components of cloth-on-spartite magnets, is M9. A1.81 and so on! When manufacturing rare earth cobalt-based magnets, it is important to have geological formations in an inert atmosphere such as refined argon, especially during the production of this magnet, which is exposed to high temperatures. The importance of non-oxidizing tlII gas during sintering is enforced.

From the above points, especially! Japanese Patent No. 52-4421 proposes that it is effective to use an aqueous-containing atmosphere at the time of formation of a rare-earth cobalt-based magnet.

However, hydrogen gas has the lowest density among all gases and has a very large diffusion barrier, so it can leak to the outside even from a small gap in the oven, i<, t*-1 at room temperature. If a water system mixes with air over a wide range of 4 to 76 volumes under normal pressure, a small ignition source will cause a large explosion.
In view of the above-mentioned point, the use of water-based gas in large quantities in industrial storm accumulation is extremely dangerous and requires extreme caution. Special 1 first
In 1982-1-6040, it was discovered that two-stage II & Rui under specific conditions were effective during sintering, and Kobal F1 Cobal Sea copper metal, Cobalt-iron-copper alloy, and Kobal F-sintered metal containing rare earth metals were discovered. - AI that molds rare earth cobalt alloy powder made of nickel-copper alloy etc. and freezes this molded body
IK% bottle lXl0 T@rr The temperature is raised from normal temperature to 800°C in a vacuum atmosphere of 4 to 50 degrees Celsius, and then the briquettes are heated to 960 to 1250°C under reduced pressure of 50 to 350 orr (argon gas)-atmosphere. A method for manufacturing rare earth-Fupal based permanent magnets sintered in a range 9 is proposed.

However, the manufacturing method of the above-mentioned application has the problem that the dependence of the magnetic properties on the sintering temperature is extremely large, and the sintering temperature range suitable for HVSO forging of rare earth-Fupal F alloys of a specific composition is very narrow. 9. In other words, if the sintering temperature is slightly lower than the maximum temperature, the sintering reaction of the powder compacted body will not proceed sufficiently, resulting in a sintered body with many pores, resulting in poor magnetic properties. The resulting sintered body does not have a degree close to the theoretical VB degree, and
If the temperature is slightly higher than the optimum sintering temperature, a large amount of melt phase will occur in the powder compression molded body, and the density will be sufficiently high. magnetic properties 0
III does not form.

This invention is an improvement on the problem of tsunzu-kami-no-gold steel, and rare earth elements! An R-1° permanent magnet alloy consisting of the far-transferring metal element lAM (for friends, l is Y# t, C・@"1N (
1, s#Ih and -Cttsuvuipw), 181 or 2
11 combinations of seeds and above, M is C and C@, F or N
1 or a combination of two or more of them, and a part of the above transition metal MO, 1, vcM, 'rt, Nb, Zr
, Ta, Hf (round string combination) to make the rare earth copal based alloy into a fine powder with an average grain size of 2 to 10 mm, - Kochu Dereme machine, etc. A compressed body is produced. Next, sintering is performed to increase the density of the formed body and improve the magnetic properties of the final product. Gradually remove the acid S-steam and water S-gas into a vacuum, followed by a vacuum in argon gas-
In order to maximize the effect of sintering, perform the following steps before sintering.

The temperature increase process in the trench from II temperature to 10 Torr (IO'C or lower) prevents saponification in the Ganu formation and Okazaki.
In the following vacuum tm air, perform slow b and ascent 1 at a speed of 4 to snow 0"Q/xi@, the reason for limiting the ascending Kaede encounter is 4"C
y'ml Ill unconditioned OJ! In terms of temperature shielding, it takes more than 3 hours to raise the temperature to 800°C, and even in a vacuum TTS + air, the molded product oxidizes during that time. 19. If the temperature rise rate exceeds 1, it is appropriate to raise the temperature. In particular, at the temperature increase of about 4, the large amount of adsorbed and occluded gas in the formed metal body is about 90 hiss.
～@OO”Cf) Temperature range■ Since it is emitted, this temperature I
Il! The appropriate temperature increase for O is 4"lO'C/551m+, lXl0-'~1x10-mt err High vacuum 1B-
It is preferable to effectively perform the degassing electric field while taking care to prevent oxidation.

111B) One electric maple degree retention at temperatures in the temperature range of 1286°C and 011B increases the density after sintering to near the coral density and improves magnetic properties. Round it off, 5O-8! The pressure is reduced to IOT/tr and the test is carried out in a 9-ygon gas atmosphere.

After the fusion is completed, the cylinder is heated at a temperature of 1100 to 110 degrees Celsius, which is slightly lower than 1 degree, under reduced pressure or normal pressure, 0 to 11 degrees of argon, and the melt generated during sintering is carried out. The nine-crystalline phase is sufficiently reacted with the nine-crystalline phase to homogenize the composition. This solution treatment is carried out either by cooling the sintering machine to room temperature and then raising the temperature again to perform solution treatment, or by cooling the sintering machine to the humidity level without cooling in a rich oven and then cooling it to the solution treatment humidity. Even after chemical treatment, the obtained properties are the same.

After the solution treatment Jl & layer is completed, a rapid insulation cooling layer of 160'C/rigidity or higher is performed, KL is applied to obtain a single phase with a homogeneous structure obtained by solution treatment at W1 temperature, and finally an aging treatment is performed. Alms Permanence - Obtain stones.

Here, the reason for limiting the argon pressure is 50T.
When the pressure becomes lower than @rt, the composition of the rare earth cobalt-stone alloy, especially 'Ik earth vapor pressure, is 800'.
At C or above, 20~sOT・rr and the highest roundness among metal elements, rare earth metals emit preferentially into the Kl atmosphere, and the final organ becomes a different round formation from the place*iii formation, resulting in -negative characteristics. Increase the amount of deterioration by 1. In addition, when the pressure is high, sufficient improvement in density is not observed with 350T and 350T.
It is assumed to be 0T・rr.

The reason for limiting the sintering temperature range is that the optimum sintering temperature range for rare earth cobalt magnet alloys varies depending on the constituent components and the proportions of each component. If the sintering temperature is less than 1250°C, sufficient sintered density cannot be obtained, and if the sintering temperature exceeds 1250°C, the alloy will melt and a sintered I*S stone body with good properties will not be obtained.

In addition, the reason why the solution treatment l & weir is subjected to rapid cooling treatment at a cooling rate of 1100 mm - 11 or more, and then the cooling process is performed at a cooling rate of 1.0 mm or more is that when cooled at a creep cooling rate of less than 200 T, / This is because precipitates are generated from a single homogeneous phase obtained during solution treatment, and excellent magnetic properties cannot be obtained after aging.

The effects of this invention method will be described below with reference to Examples.

Example 1 C with a purity of 9-9 or more Oam 27.1 wtlg and a purity of H1all.

49.3 wtl, F@7.7wt1, Nl
The alloys consisting of &Owt- and C60,9wt- were coarsely ground in a high-frequency melting μ-iron mortar in an argon atmosphere.

The coarsely pulverized powder was ball milled in an organic solvent to form a fine powder with an average particle size of 2 to 10 μm, and the resulting fine powder was pressed in a magnetic field of 12 KO· to form a compact compact.

The compressed body thus obtained was heated to 800° C. at a rate of 10 Roux 11 in a vacuum atmosphere of 1×1OT@rr. In a reduced pressure argon gas atmosphere of 200 Torr, the temperature axis of 1181 Juku and 1220 ° C.
After applying the solution in a compressor for 2 hours at 1180°C for xi hours, it was rapidly cooled to 500°C at a moderate cooling temperature of 7'wsiH, and then aged at 800°C for 4 hours.
Characteristics were measured.

In addition, as a comparative example, the above molded body was heated from 1180°C to 1°C in a reduced pressure argon I gas atmosphere of 2007 orr.
After sintering in a temperature range of 220°C, it was rapidly cooled without solution treatment, followed by aging treatment at 800°C for 4 hours, and its properties were measured.

- The measurement results of negative characteristics are summarized in Figure 1.

FIG. 1 shows the relationship between sintering temperature and instantaneous properties when solution sensitization is performed after fusion and when only sintering is performed. Table 1 also shows a comparison example of the method of the present invention for the case where the best magnetic properties were obtained at a sintering temperature of 1200°C.

As is clear from the above results in Table 1, according to the present invention, not only excellent magnetic properties are observed, but also a wide sintering temperature range, resulting in industrially stable manufacturing conditions.

Example 2 S#1 with a purity of 99.911 or more: 24L1wt Co with a purity of 99.916 or more: 7.7wt%'@
: 1&2wt1, C11: 4Q, 7vtllMn
An alloy consisting of: 0.5vtll, Zr: 0.8wt1G was melted in an arc button in an argon gas atmosphere, and coarsely ground in an iron mortar in an argon atmosphere. The coarsely pulverized powder was pulverized by a jet mill using nitrogen gas to obtain a fine powder with an average particle size of 2 to 10 mesh. Step 9: The obtained fine powder is press-molded in a magnetic field of 10 KO· to produce a compression-molded body.

The compressed body thus obtained was heated to 800'C1 at a rate of 10°C/wxffi@ in a vacuum atmosphere of 30 Torr, and then heated to 1200°C in a reduced pressure argon gas atmosphere of 250 Torr. , sintered for 2 hours,
Subsequently, it was subjected to solution treatment at 1180"C for 2 hours, and then rapidly cooled in liquid nitrogen at a moderate cooling rate of 700"C/1111m.Then, the temperature was lowered from 850°C to 450°C in an argon atmosphere. !Ninth stage of aging treatment.

Comparative rounding, the same island coral as above was applied without solution treatment I & weir.

Table 2 shows the measurement results of the properties of nine samples subjected to the above-mentioned method of the present invention and the comparative heat treatment.

As shown in Table 2 and above, according to the method of the present invention, when using a gas that is considered dangerous, such as hydrogen gas, the temperature is first raised to 800°C in a vacuum atmosphere in the sintering process. After continuous sintering in a reduced pressure argon gas atmosphere, aging treatment is carried out using solution-cooled D*IIA, which is effective in increasing the density and also has excellent magnetic properties. This is a very effective method for rounding up magnets.

[Brief explanation of drawings]

Figure 1 shows the melting temperature and Br, (Bil)llax
The curve that connects the O marks shows the case where the solution layer is applied at 1180℃ after instant solidification, and the curve that connects the Δ marks shows the case where the material remains sintered. .

Claims (1)

[Claims] R-11 series permanent-base alloy consisting of 14 earth oxide lAl and transition metal element M (Kudashi, wing is Y* LIs C@s P
reN4. tjss * and donation of 1 or 8 or more of the field (Mitsu V Yumeru), M is CM and Co, ir- or a combination of 1 or 2 or more of the combinations and the above transition metal MO Partially K &h+, 'rl, Nb,
When molding a rare earth coparsium powder consisting of a combination of Zr, Ta, and at least one of the principal elements of HE, and molding this molded body, a bottle of I x 10
800'C from base magnet at KH in vacuum below Torr
Magnetized at 4 to 20T7*i@ to below, sintered in a reduced pressure argon fX atmosphere of sO to 35 O Torr in a temperature range of 110G to 1250℃, and then sintered in a temperature range of 1100 to 1200℃ 1ml of solution solution
2. A method for producing rare earth cobalt permanent magnet OIl, characterized by performing rapid cooling at a temperature of 2 tJ O'C/mi or more and performing an aging treatment.