JPH02159337A - Permanent magnet alloy - Google Patents

Abstract

PURPOSE:To increase the coercive force of the alloy in the low range of Cu amt. and to improve its maximum energy product by adding suitable amounts of O and C to a rare earths-Co-Fe-Cu-Zr series. CONSTITUTION:The compsn. of a permanent magnet alloy is constituted of, by weight, 22 to 28% R (one or more kinds of rare earth elements including Y), 5 to 27% Fe, 3 to 10% Cu, 0.5 to 6% Zr, 0.03 to 0.8% O, 0.005 to 0.5% C and the balance Co. In the alloy, by the addition of O and C, the rectangular hysteresis properties of an 4pi1-H loop are made better and its maximum energy product is improved while the merit of improving the coercive force at the time of adding conventional C only is kept alive as it is.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is directed to R 2
Regarding M+7 series (however, R is a rare earth element containing yttrium and M mainly represents a transition metal) permanent magnet alloy,
R2 with particularly good squareness of the 4πI-H loop of the demagnetization curve
This relates to M+7 series permanent magnet alloy.

(Prior Art) A 2-17 type rare earth permanent magnet material based on R-Co-Fe-Cu is conventionally known. In this type of alloy material, C
The addition of u has the effect of increasing the coercive force iHc, and
% or more was considered necessary. However, when the amount of Cu added increases, a problem arises in that the residual magnetic flux density Br decreases.

To solve this problem, a technology has been reported that suppresses the amount of Cu, which is a non-magnetic material, and adds an appropriate amount of Zr instead, suppressing the decrease in B and increasing the maximum energy product (BH) flax. (For example, Japanese Patent Publication No. 55-47097).

Furthermore, in order to improve the squareness of the 4πI-H loop, R
A technique for incorporating O into the 2M17 system has been reported (for example, JP-A-57-134533).

In addition, in order to improve iHc, C was added to the R2M +7 system.
Techniques have also been reported to contain (for example, the
6-36858).

(Problem to be solved by the invention) However, in the R-Co-Fe-Cu-Zr permanent magnet alloy in which Cuff1 is suppressed and Zr is added instead, CuEt, which is a non-magnetic substance, is suppressed to a small amount. B
Although r is improved and (BH)max is increased as a result, it is still not as high as (BH)may, which is (BH)max-(Br)2/4.

In addition, in the case where O is added to the R2M17 system in order to improve the squareness of the 4πI-H loop, the 4πI-H
The squareness of the loop is good, but the coercive force iHc is small.

Furthermore, many of the R2M17 systems in which C is added to increase the iHc have poor squareness of the 4πI-H loop.

The present invention has been made in view of the above points, and its purpose is to have a high iHc in a low Cuff1 region of 10 wt% or less, and to improve the squareness of the 4πI-H loop compared to conventional products. An object of the present invention is to provide a permanent magnet alloy having high (BH) wax.

(Means for Solving the Problems) In order to achieve the above object, the present inventors have developed R-Co-F
Regarding e-Cu-Zr rare earth permanent magnet materials, high iH
As a result of various studies on improving the squareness of the 4πI-H loop in c, that is, improving (BH) wax, we found that O
The present invention was completed based on the findings that it is sufficient to add appropriate amounts of both C and C.

That is, in the present invention, R is 22 to 28 wt% (wherein R is one or more rare earth elements including yttrium).

5-25 wt% Fe, 3-10 wt% Cu, 0°5
~6wt% Zr, 0.03~0.8wt% 0゜0
．． The present invention relates to a permanent magnet alloy characterized in that the balance of C2 of 0.05 to 0.5 wt% consists essentially of Co.

(Function) In this way, 0 and C are added to the R-Co-Fe-Cu-Zr system.
By adding , in the present invention, the advantage of improving the coercive force iHc when only C is added is taken advantage of, and the disadvantage that (BH)max is not improved much is eliminated from the conventional case when only adding O. The advantages of 4
This problem can be solved by improving the squareness of the πI-H loop.

Therefore, according to the present invention with a specific composition in which both C0 and C are added, the permanent Higher iHc can be obtained than magnetic alloy, and R-Co-Fe-Cu
It is possible to improve the squareness of the 4πI-H loop compared to -Zr-based or R-Co-Fe-Cu-Zr-C-based permanent magnet alloys. Therefore, high (BH)IIaX can be obtained while having high iHc.

In order to exhibit the above effects, the composition of the permanent magnet alloy according to the present invention was specified as described above.

The composition ratio of each component will be explained below.

The ratios of R, Co, and Fe are approximately the same as those conventionally commonly used in this type of ternary composition.

In other words, the reason for setting R to 22 to 28 wt% is that if it is less than 22 wt%, iHc will be small, and if it exceeds 28 wt%, B
This is because r decreases.

The reason for setting Fe to 5 to 25 wt% is that if it is less than 5 wt%, B
This is because r is low and iHc decreases when it exceeds 25vL%.

The reason why the Cu content was set to 3 to 10 wt% was 3
This is because when p is less than vL%, iHc does not occur, and when it exceeds 10wt%, Br decreases.

In addition, the content of Z" was set to 0.5 to 6 wt% because 0.
, less than 5wt%, iHc does not occur, and if it exceeds 6wt%, Br decreases.

The reason for setting the content of 0 to Oo 03 to 0.8 wt% is that 0
．． If it is less than 03νt%, there is no effect of O addition, and 4π1-H
Although no improvement in the squareness of the loop is observed, even if it exceeds 0°8νt%, the squareness of the 4πI-H loop becomes poor (and B' also decreases).

The reason why the C content was set to 0.005 to 0.5 wt% was 0.
．． If it is less than 0.005 wt%, the iHc increasing effect will not be expressed,
This is because if it exceeds 0.5 wt%, Br decreases.

In addition, in the present invention, the method for incorporating O is as follows:
For example, when an alloy material is pulverized with a jet mill, there is a method in which a suitable amount of oxygen is mixed into nitrogen, which is a carrier gas, to mix the alloy material fine powder and the C fine powder.

(Example) Present Example 1 (Composition of alloy) Sm: 24.3 wt% Fe: 12.5 wt% Cu near, 8 wt% Zr: 1.5 wt% C: 0.1 wt
%0: 0.02-0.9wt%Co: Remainder (pre-process) The required alloy material was melted in a high-frequency melting furnace or an arc melting furnace, coarsely pulverized by a show crusher, and then finely pulverized by a jet mill. .

During this fine pulverization, an appropriate amount of oxygen is mixed into the jet,
It was included in the above alloy material.

The finely pulverized powder was mixed with an appropriate amount of C powder and compression molded in a magnetic field of 15 kOe at a molding pressure of 2 ton/cj.

(Heat treatment) The above molded product was heated to 11% depending on the O content in the molded product.
Sintering was performed for 4 hours at 70 to 1190°C (the higher the Ojl, the higher the temperature), and solution treatment was performed for 3 hours at a temperature of 1120°C or higher and lower than the sintering temperature.

Thereafter, an aging treatment was performed at 820° C. for 3 hours, and subsequently, the material was cooled to 400° C. at a cooling rate of 2° C./ml.

i Hc, B r, (BH)aaX for the content of 0
The measurement results are shown in Table 1.

Moreover, the demagnetization curve of the 4πI-H loop with respect to the content of 0 is shown in FIG.

Table 1: When the oxygen content is less than 0.03 wt%, the squareness of the 4πI-H loop is poor and the (BH) saw is low.

In addition, when the oxygen content exceeds 0.8 wt%, B' decreases, and the squareness of the S24πI-H loop worsens, and (
BH) llaX also becomes lower.

Furthermore, since 0.1 wt% of C was contained, all iHc values were good.

The reason for increasing the sintering temperature as the amount of O increases is to increase the sintered density as much as possible by sintering at a high temperature.
This is to increase the

Example 2 (Composition of alloy) Sm: 24.3wt% Fe: 12.5wt%Cu, 8wt% Zr2, 1.5wt%C: 0.00
3 to 0.8 wt% O: 0.1 wt% Co: Remaining part (previous step) Same as Example 1 (heat treatment) The molded product obtained in the previous step was treated according to the content of C in this molded product. Sintering was performed for 4 hours at 1170 to 1200°C (the higher the CJI, the higher the temperature), and solution treatment was performed for 3 hours at a temperature of 1120°C or higher and lower than the sintering temperature.

Thereafter, aging treatment was performed at 820°C for 3 hours, followed by cooling to 400''C at a cooling rate of 2°C/1 inch.

Table 2 shows the measurement results of iHc, Br, and (BH)maX with respect to the C content.

Table 2 When the carbon content is less than 0.005 wt%, iHc is small, and therefore (BH)wax is small relative to the size of Br.

Further, when the carbon content exceeds 0.5 wt%, Br decreases1, and therefore (BH)wax also decreases.

Furthermore, since it contains 0.1 wt% of O, 4πl-
1 (the squareness of the loop is 0-containing ff of Example 1)
It was almost the same as that of 1O, 1wt%.

Note that the reason why the sintering temperature was made higher as the amount of C increased was to increase the sintered density and improve the Br, as in the case of Example 1.

*Example 3 (Alloy composition) S m: 20.5 to 28.7 wt% Fe: 12
．． 5wt% Cu near, 8wt% Zr: 1°5w
t%C: 0.1wt% 0:0.1wt%Co
: Remaining part (previous step) Same as Example 1 (heat treatment) The molded product obtained in the previous step was heated at 11BO to 1210°C depending on the Sm content in the molded product (the higher the S weight, the lower the temperature). Sintering was performed for 4 hours on the side), and solution treatment was performed for 3 hours at a temperature of 1120° C. or higher and lower than the sintering temperature.

Thereafter, aging treatment was performed at 820°C for 3 hours, followed by cooling to 400°C at a cooling rate of 2°C/mln.

i Hc, B r, (BH) Il with respect to Sm content
The measurement results of aX are shown in Table 3.

When the content of Sm in Table 3 is less than 22.0wt5, iHc becomes low. Moreover, when the Sm content exceeds 28.0w1%, Br decreases.

*Example 4 (Alloy composition) Sm: 24.3wt% Fe: 12.5wt%Cu
: 2.3-11.1wt% Zr: 1.5wt%
C: 0.1 wt% 0: 0.1 wt% Co: Remainder (previous step) Same as Example 1 (heat treatment) The molded product obtained in the previous step was treated according to the content of Cu in this molded product. Sintering was performed for 4 hours at 1170 to 1200°C (the higher the amount of Cu in the molded product, the lower the temperature), and solution treatment was performed for 3 hours at a temperature of 1120°C or higher and lower than the sintering temperature.

After that, the Cu content is 6.0 to 11. The lwt% sample was aged at 820° C. for 3 hours and subsequently cooled to 400° C. at a cooling rate of 2° C./in.

In addition, for samples with a Cu content of 2.3 to 4.7 wt%, the first stage aging was performed at 650°C for 3 hours and at 830°C for 3 hours.
A second stage aging for 2 hours followed by 2℃/ll1in
It was cooled to 400°C at a cooling rate of .

i Hc, B r, (BH) II for Cu content
The measurement results of aX are shown in Table 4.

Table 4 When the Cu content is less than 3.0 wt%, iHc becomes low. Moreover, the Cu content is 10. If it exceeds Owt%, Br decreases.

In this example, the specific effect treatment was changed to two stages because when Cufi is less than 5 wt%, iHc does not develop even if the same one-stage aging treatment as for compositions with Cu content of 5 wt% or more is performed, and the two-stage This is because iHc is expressed during aging treatment.

*Example 5 (Alloy composition) Sm: 24.3 wt% Fe: 12.5 wt% Cu near, 8 wt% Z r: 0.3 to B, 8 wt%
C: 0.1 wt% O: 0.1 wt% Co: Remainder (previous process) Same as Example 1 (heat treatment) The molded product obtained in the previous process was treated according to the Zr content in this molded product. and 1170 to 1200°C (the higher the Zr content, the
Sintering was performed for 4 hours at a high temperature (high temperature side), and solution treatment was performed for 3 hours at a temperature of 1120° C. or higher and lower than the sintering temperature.

Thereafter, aging treatment was performed at 820°C for 3 hours, followed by cooling to 400°C at a cooling rate of 2°C/n+in.

iHc, Br, (BH)ffia for Zr content
The measurement results for X are shown in Table 5.

Table 5 When the Zr content is less than 0.5 νt%, iHc becomes low. Moreover, the Zr content is 6. If it exceeds Owt%, Br decreases.

Note that the reason why the sintering temperature was increased as the amount of Zr increased was to increase the sintered density and improve B'', as in the case of Example 1.

*Example 6 (Alloy composition) S m: 12.3 to 24.3 wt% Ce: O
~12. owt% (However, Sm+Cem24.3wt%) Fe: 12.5wt% Cu near, 8wt% Zr: 1
．． 5wt% C: 0.1wt% 0: 0.1wt%
Co: Remaining part (previous step) Same as Example 1 (heat treatment) The molded product obtained in the previous step was heated to 1140 to 1180°C depending on the Ce content in this molded product (the higher the Ceffi, the more
Sintering was performed for 4 hours at a low temperature (low temperature side), and solution treatment was performed for 3 hours at a temperature of 1120° C. or higher and lower than the sintering temperature.

Thereafter, an aging treatment was performed at 820°C for 3 hours, and subsequently, the material was cooled to 400°C at a cooling rate of 2°C/1n.

iHc, Br, (BH)01aX with respect to Ce content
The results are shown in Table 6.

As described above, the characteristics deteriorate as the amount of Ce substitution increases, but sufficient characteristics can be obtained for practical use even if a portion of Sm is replaced with Ce. This clearly shows that the present invention is effective even in the case of rare earth elements (including yttrium) other than Sm.

(Effects of the Invention) As described above, according to the permanent magnet alloy according to the present invention, while generating a coercive force equivalent to or higher than that of the prior art, 4πI-H
The squareness of the loop can be made better than in the prior art.

As a result, the maximum energy product can be improved.

[Brief explanation of the drawing]

FIG. 1 shows 4πI-H in the first embodiment according to the present invention.
It is a graph showing a loop demagnetization curve. Patent applicant Fuji Electrochemical Co., Ltd. Representative
Person Patent Attorney - Ken Sukedo Iro
Patent Attorney Masatoshi Matsumoto Table 6

Claims (1)

[Claims] 22-28 wt% R (however, R is one or more rare earth elements including yttrium), 5-25 wt% Fe, 3-25 wt%
10wt% Cu, 0.5-6wt% Zr, 0.03
~0.8wt% O, 0.005~0.5wt% C,
A permanent magnetic alloy characterized in that the balance consists of Co.