JPS60144909A - Manufacture of permanent magnet material - Google Patents

Abstract

PURPOSE:To enhance a residual magnetic flux density and coersive force and simultaneously further improve magnetic characteristic expressed by the miximum energy product by forming a permanent magnet using a material mainly composed of particular rare earth elements and iron. CONSTITUTION:As a material of permanent magnet, a composition expressed by R1-alpha-beta-gammaFealphaMbetaXgamma is used. Here, R is one or two or more kinds of rare earth element, and M is one or two or more kinds of Ni, Co, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W. X is one or two or more kinds of B, C, N, Si, P and values of alpha, beta, gamma satisfy the relations, 0.60<=alpha<=0.85, 0<=beta<=0.20, 0<=gamma<=0.15. An alloy of such composition is smashed and is then molded under the magnetic field and thereafter sintered. It is then heat processed and a magnet material can be obtained. In this case, after the sintering, a material is cooled up the 530-750 deg.C at a cooling rate of 0.5-10 deg.C/min and then held at this temperature for 0.2hr or longer. Thereafter, it is cooled up to a room temperature at a cooling rate of 30 deg.C/min or higher.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention provides a permanent magnet that can be used in a wide range of applications such as home appliances, audio products, watch parts, automobile parts, precision instruments, etc. The present invention relates to a method for manufacturing materials, and particularly to a method for manufacturing permanent magnet materials mainly containing rare earth elements (R) and iron (Fe).

(Prior art) In recent years, the maximum energy product ((B H
) maw ) has been significantly improved compared to the previous alnico magnet materials, etc., and has been particularly effective in reducing the size and weight and improving the performance of home appliances, audio products, watch parts, automobile parts, precision equipment, etc. Contributing.

Conventionally, rare earth-cobalt magnets have been typical as permanent magnet materials with such excellent properties, and their maximum energy product ((B H) maw) is 18 to 28 MG.
・It shows a fairly high value of about Oe. However, research to further improve the maximum energy product ((BH) Wa ing. Although there are Nd-Fe-B based rare earth-iron magnet materials, as a result of further research based on this, the present inventors found that the
We have newly discovered that the cooling rate and holding temperature greatly affect the magnetic properties, especially the coercive force, in the heat treatment of d (REM) -F e -B system and similar rare earth-iron system permanent magnet materials. This led to the completion of the invention.

(Object of the Invention) This invention relates to the RE of the above-mentioned Nd-Fe-B system.
In M-Fe-B-based and similar rare earth-iron based permanent magnet materials, residual magnetic flux density (Br), coercive force (B
Hc, rHc) and the maximum energy product ('(BH) w
An object of the present invention is to provide a method for manufacturing a rare earth-iron permanent magnet material that can further improve the magnetic properties represented by R
□-6-β-A is represented by Fe, MβXy, R is one or more rare earth elements, M is Mn, Ni, Co,
Ti, Zr, Hf, V.

Nb, Ta, Cr, MO, W (7) 1 type or 2 or more types, X is B, C, N, Si, Pc7) 1 type or 2 types
species or more, 0.60≦α≦0.85. 0≦β≦0.20. After pulverizing an alloy with a composition of 0≦γ<0.15 and forming it in a magnetic field, it is sintered and heat treated to produce a permanent magnet material. 530-75 in speed
Cool down to 0°C and cool down to 0 in the temperature range of 530-7500C.
．． It is characterized in that it is held for 2 hours or more and then cooled to room temperature at a cooling rate of 30° (!/min or more).

The permanent magnet material to which this invention is applied is represented by the general formula, R1-ct-β-,yFeoMβxa, as described above.
R in the formula represents one or more rare earth elements, including Nd and Sc.

Y, La, Ce, Pr, Pm, Sm, Eu.

Gd, Tb, Dy, Ho, Er, Tm, Yb.

One or more types of Lu are used.

In addition, in the above general formula, Fe (iron) is 0.60≦
The range is α≦0.85. Here, if the amount of Fe is too large, the residual magnetic flux density (Br) will improve, but the coercive force (BHC) will increase.

Since the excellent maximum energy product ((B H) wax ) can no longer be obtained due to the extreme decrease in IHc), α
≦0.85. On the other hand, if the amount of Fe is too small, the residual magnetic flux density (Br) will be low and the maximum energy product ((BH
) mat ) decreases, so 0.60≦α is set.

Furthermore, in the above general formula, M is Mn.

Ni, Co, Ti, Zr, Hf, V, Nb.

One or more of Ta, Cr, Mo, and W, and O
The range is ≦β≦0.20. Also, XhaB,
C, N, S i , P(7) 114 2 or more types, and the range is 0≦γ<0.15. Here, by adding the above M in combination with the above element It is an element that has a remarkable effect on improving r).

However, if the amount of M is too large, the above-mentioned borides, carbides, nitrides, and silicides may be formed.

Since the amount of phosphide etc. formed increases and the magnetic properties deteriorate, β≦0.20 is set. Furthermore, the X element has the effect of raising the Curie point of rare earth-iron magnets, such as Nd-Fe magnets, from room temperature to over 300°C; however, if the amount of X is too large, the coercive force ( BHC, IHC
) and residual magnetic flux density (B r) decrease, making it impossible to obtain an excellent maximum energy product ((B H) max ), so O≦γ<0.15 was set.

When producing a permanent magnet material from an alloy having such a composition, the alloy is crushed and formed in a magnetic field, and then sintered and heat treated. / Wound cooling rate: 530-750℃
The sample is cooled to a temperature of 530 to 750° C. for 0.2 hours or more, and then cooled to room temperature at a cooling rate of 30° O/min or more.

Here, the reason why the cooling rate after sintering is set to 0.5 to bmin is that when the cooling rate is outside this range, the magnetic properties, especially the coercive force (
BHc, zHc) and the maximum energy product ((BH) m
This is because ax ) decreases. In addition, the holding temperature after cooling was set at 530 to 750 °C because magnetic properties, especially coercive force (BHc, IHC) and maximum energy product ((BH) wax) decrease when outside this range. The reason why the holding time at 530 to 750°C is set to 0.2 hours or more is because if the holding time is too short, the magnetic properties, especially the coercive force (BHC).

IHc) and maximum energy product ((BH) max )
This is because the In this case, even if the magnetic properties are kept for too long, the magnetic properties will not improve much, so it is preferable to keep it for about 0.2 to 5 hours in consideration of productivity and workability.

Furthermore, the reason why the cooling rate after holding was set to 30°c/min or more is because if the cooling rate is too low, the magnetic properties
In particular, this is because the coercive force (BHC, IHC) and maximum energy product ((BH) ma decrease.In this case, even if the cooling rate is increased too much, the magnetic properties will not improve much, so workability etc. 100° from the surface (!/min
It is sufficient to keep it below this level.

(Example 1) An alloy having a composition of NdO, 17FeO, 75SiO, 05"0.03 was melted using a button melting furnace adjusted to an argon atmosphere.Then, the melted alloy was coarsely ground in a mortar. The mixture was pulverized to an average particle size of about 4 pm using a jet mill.

Next, the obtained powder was heated to approximately 2 tons in a magnetic field of 15 KOe.
After press forming under a pressure of f/cm2, the obtained molded body was sintered at 1000°C for 1 hour in an argon atmosphere, and then cooled to 650°C at a cooling rate of A'O/min. Cool to 650'C! After being held for 1 hour, it was cooled to room temperature at a cooling rate of 50°Q/min.

Next, the residual magnetic flux density (Br), coercive force (BHC, IHC), and maximum energy product ((B
H) max ) was investigated, and the results are shown in Table 1.

As shown in Table 1, cases where the cooling rate after sintering satisfies the range of the present invention and cases of 2 to 5 show excellent magnetic properties, whereas the cooling rate is too low. Yang,
It is clear that in the cases of No. 1 and No. 6, in which the cooling rate is too high, the magnetic properties are inferior to those of the present invention.

(Example 2) An alloy having the same composition as in Example 1 was melted and then coarsely crushed and finely crushed in the same manner as in Example 1.

Next, the obtained powder was heated in a magnetic field of 15 KOe for about 2 to
After press molding under a pressure of nf/cm2, the obtained molded body was heated at 1000°C in an argon atmosphere.
Sintering was performed under the conditions of 1 hour at , then cooled to T'O at a cooling rate of 1'C/min, held at T'C for 1 hour, and then cooled to room temperature at a cooling rate of 50°O/win. did.

Next, the residual magnetic flux density (Br), coercive force (BHC, IHC), and maximum energy product ((B
H) wax) was investigated, and the results shown in the second category were obtained.

As shown in Table 2, cases No. 12 to No. 16, where the holding temperature after cooling satisfies the range of the present invention, all show excellent magnetic properties, whereas cases where the holding temperature is too high show excellent magnetic properties. , 11 and 17, in which the holding temperature is too low, it is clear that the magnetic properties are inferior to those of the present invention.

(Example 3) An alloy having the same composition as in Example 1 was melted and then coarsely and finely pulverized in the same manner as in Example 1.

Next, the obtained powder was heated in a magnetic field of 15 KOe for about 2 to
After press molding under a pressure of nf/cm2, the obtained molded body was heated at 1000°C in an argon atmosphere.
Sintering was performed for 1 hour at a cooling rate of 1°C/min, then cooled to 650°C at a cooling rate of 1°C/min, held at 650°C for t hours, and then cooled to room temperature at a cooling rate of 50°C/min. .

Next, the residual magnetic flux density (Br), coercive force (BHC, IHC), and maximum energy product ((B
I()wax) was investigated and the results are shown in Table 3.

As shown in Table 3, when the holding time after cooling was set to 0.2 hours or more, all showed excellent magnetic properties, whereas in No. 1.2, where the holding time was too short. In some cases, it is clear that the magnetic properties are inferior to those of the present invention.

In addition, sufficient magnetic properties can be obtained if the holding time is 5 hours, and no significant improvement in magnetic properties is observed even if the holding time is longer than this, so the holding time is 0.2 to 5 hours.
It has become clear that increasing the time is better.

(Example 4) An alloy having the same composition as in Example 1 was melted and then coarsely and finely pulverized in the same manner as in Example 1.

Next, the obtained powder was heated to approximately 2 tons in a magnetic field of 15 KOe.
After press forming under a pressure of f/am2, the obtained molded body was sintered at 1000°C for 1 hour in an argon atmosphere, and then cooled to 650°C at a cooling rate of 1°C/+nin. After holding at 650°C for 1 hour, Q'C! The mixture was cooled to room temperature at a cooling rate of /win.

Next, the residual magnetic flux density (Br), coercive force (BHC, rHc), and maximum energy product ((B
H) wax) was investigated, and the results are shown in Table 4.

As shown in Table 4, the cooling rate after holding is 30'Q≠.
It is clear that in the cases of o, 1, and 2, the magnetic properties are inferior to those of the present invention.

In addition, sufficient magnetic properties can be obtained if the cooling rate is up to about 70°C/min, and no significant improvement in magnetic properties is observed even if the cooling rate is higher than this, so the cooling rate after holding is It has become clear that it is good to set the rate to about 30 to 70'O/'min.

(Example 5) Alloys having the compositions shown in Table 5 were melted using a button melting furnace adjusted to an argon atmosphere. Next, the molten alloy was coarsely ground in a mortar and then ground to an average particle size of 4 pm using a jet mill.
It was pulverized to a certain extent.

Next, the obtained powder was heated in a magnetic field of 15 KOe for about 2 to
After press molding under a pressure of nf/cm2, the obtained molded body was heated at 1000°C in an argon atmosphere.
Sintering was performed under the conditions of 1 hour at 2° C./win, then cooled to 630° C. at a cooling rate of 2° C./win, held at 630° C. for 2 hours, and then cooled to room temperature at a cooling rate of 60′07 m1n.

Next, the residual magnetic flux density (Br), coercive force (BHC, IHC), and maximum energy KN (
(B H) mar), the results are shown in Table 5.

As shown in Table 5, by employing the heat treatment conditions of the present invention, the magnetic properties of the rare earth-iron permanent magnet material can be significantly improved to C, and β=0, that is, M
Excellent magnetic properties were also obtained in the case of 43 to 45, which do not contain any elements.

(Effects of the Invention) As described above, in the method for producing a permanent magnet material of the present invention, the general formula % is one or more rare earth elements, and M is Mn.

Ni, Co, Ti, Zr, Hf, V, Nb.

Ta, Cr, MO, W (7) one or more types, X
is one or more of B, C, N, St, and P, and 0.60≦α≦0,85. 0≦β≦0.20. When producing a permanent magnet material by pulverizing an alloy having a composition of 0≦γ<0.15 and forming it in a magnetic field, followed by sintering and heat treatment, a cooling rate of 0.5 to 10°C/min after sintering is used. 530-750
0.2 in the temperature range of 530-750°C.
The residual magnetic flux density (
Br), coercive force (BHC, IHC), maximum energy product (
It is possible to manufacture permanent magnetic materials with extremely excellent magnetic properties expressed by etc. can be realized from the perspective of permanent magnets, which can bring about very excellent effects.

Patent applicant: Daido Steel Co., Ltd. Representative Patent Attorney Yutaka Shio

Claims (1)

[Claims] (1) Formula, represented by R1-(x-β-yFe, Mβxa, R is one or more rare earth elements, M is Mn,
Ni, Co, Ti, Zr, Hf, V. Nb, Ta, Cr, Mo2, W (7) 1 type or 2 or more types, X is 1 type or 2 types of B, C, N, St2, P
species or more, 0.60≦α≦0.85. 0≦β≦0.20. After pulverizing an alloy with a composition of 0≦γ<0.15 and forming it in a magnetic field, it is sintered and heat treated to produce a permanent magnet material. 530-75 in speed
Cool down to 0°C and cool down to 0 in the temperature range of 530-750°C.
．． A method for producing a permanent magnet material, which comprises maintaining the temperature for 2 hours or more, and then cooling it to room temperature at a cooling rate of 30° C. or more than 7/min.