KR102252068B1 - ThMn12 TYPE MAGNETIC SUBSTANCE AND FABRICATION THEREOF - Google Patents

Abstract

The present invention relates to a ThMn ₁₂ type magnetic body and a method of manufacturing the same. The magnetic material according to the exemplary embodiment of the present invention may obtain a magnetic material having improved magnetic properties having excellent coercivity and high residual magnetization.

Description

ThMn12 type magnetic body and its manufacturing method {ThMn12 TYPE MAGNETIC SUBSTANCE AND FABRICATION THEREOF}

The present invention relates to a ThMn ₁₂ type magnetic body excellent in coercivity and residual magnetization and a method of manufacturing the same.

Permanent magnets are applied in a wide range of fields such as electronic devices, information communication, medical, machine tool fields, and industrial automobile motors. In particular, expectations for the development of a permanent magnet with excellent characteristics are increasing due to the increase in the spread of hybrid vehicles and the demand for energy saving and power generation efficiency improvement in the industrial field.

Currently, Nd-Fe-B-based magnets dominating the market as high-performance magnets are used in magnets for driving motors used in hybrid or electric vehicles.

In the case of a drive motor, development of a new permanent magnet material is in progress in response to the miniaturization and high output of the motor.

As one of the materials that exceeds Nd-Fe-B magnets, _{research on rare earth-iron magnets having a ThMn 12-} type crystal structure is being conducted. For example, a magnetic nitride body having _{a ThMn 12} type crystal structure containing Nd as a rare earth element has been proposed. _{Further, a magnetic body having a ThMn 12} type crystal structure including Sm as a rare earth element has been proposed.

However, there is still a demand for rare earth magnets having excellent magnetic properties such as coercivity and residual magnetization.

_{An object of the present invention is to provide a ThMn 12} type magnetic material having excellent magnetic properties such as coercivity and residual magnetization, and a method of manufacturing the same.

In order to achieve the above object, according to an aspect of the present invention, there _{is provided a ThMn 12} type magnetic body having the composition of the following formula 1:

[Equation 1]

(Sm _1-x La _x Zr _0.1 ) _a (Fe _(1-y) Co _y ) _b Ti _c

During expression

0.1 ≤ x ≤ 0.4, y = 0.2, 0.5 ≤ a ≤ 1.5, 5.0 ≤ b ≤ 18, 0.5 ≤ c ≤ 1.5.

According to another aspect of the present invention, mixing and then melting the raw material powder;

Melt spinning the melt to obtain an alloy ribbon;

Cold rolling the alloy ribbon and then heat treatment; And

There is provided a method of manufacturing _{the ThMn 12-} type magnetic material comprising the step of water-cooling the heat-treated resultant.

_{The ThMn 12} type magnetic material according to an embodiment of the present invention exhibits excellent coercivity and residual magnetization.

1 is an XRD pattern of _{ThMn 12} type magnetic bodies according to Examples 1, 2 and Comparative Examples of the present invention.
2 is a graph showing magnetic hysteresis curves at 295K of magnetic bodies according to Examples 1, 2, and Comparative Examples of the present invention.
3 is a graph showing the degree of saturation magnetization and the degree of residual magnetization of magnetic materials according to Examples 1, 2, and Comparative Examples of the present invention.
4 is a graph showing the coercive force of magnetic materials according to Examples 1, 2, and Comparative Examples of the present invention.
5 is a graph showing the maximum energy product of magnetic materials according to Examples 1, 2, and Comparative Examples of the present invention.

_{Hereinafter, a ThMn 12-} type magnetic material according to the present invention and a method of manufacturing the same will be described.

The ThMn ₁₂ type magnetic body of the present invention has the composition of the following formula 1:

[Equation 1]

(Sm _1-x La _x Zr _0.1 ) _a (Fe _(1-y) Co _y ) _b Ti _c

During expression

0.1 ≤ x ≤ 0.4, y = 0.2, 0.5 ≤ a ≤ 1.5, 5.0 ≤ b ≤ 18, 0.5 ≤ c ≤ 1.5.

According to an exemplary embodiment of the present invention, x may be 0.1 to 0.4, and specifically 0.3. For example, ThMn ₁₂ type magnetic material in accordance with one embodiment of the present invention may be a formula _{(Sm 0.6 La 0.3 Zr 0.1)} (Fe 0.8 Co 0.2) 11 Ti ₁₂ ThMn the magnetic bodies.

The magnetic compound of the present invention is represented by Formula 1 and has a ThMn ₁₂ type crystal structure. This ThMn ₁₂ type crystal structure is a tetragonal crystal, and the values of 2θ in the XRD measurement results show peaks of 29.801, 36.554, 42.082, 42.368, and 43.219° (±0.5°), respectively.

_{The ThMn 12} type magnetic material according to the exemplary embodiment of the present invention may contain a trace amount of impurity elements, although not indicated in the formula.

_{The ThMn 12-} type magnetic body according to an exemplary embodiment of the present invention has the composition of Equation 1, and thus has superior coercivity and residual magnetization compared to _{the ThMn 12-type magnetic body of other compositions.} For example, it may have a coercivity of 3500 Oe to 3600 Oe, for example 3539 Oe, and a residual magnetization degree of 95 emu/g to 100 emu/g, for example 99.2 emu/g.

_{A method of manufacturing a ThMn 12-} type magnetic body according to another aspect of the present invention comprises the steps of mixing and then melting raw powders; Melt spinning the melt to obtain an alloy ribbon; Cold rolling the alloy ribbon and then heat-treating the alloy ribbon; And cooling the heat treated product with water.

First, when the raw material powder is mixed, it may be advantageous to use a raw material powder of as high purity as possible to obtain a magnetic body having desired magnetic properties.

The amount of raw material powder used can be used in a stoichiometric ratio to have the composition of Equation 1 above, but since Sm has a lower boiling point than other elements, it is used in an amount of 170% or more than the amount according to the original stoichiometric ratio. It may be desirable.

In the step of melting the mixed raw material powder, the melting method is not particularly limited, and any method generally used in the field of magnetic body manufacturing may be used. For example, it can be carried out by a plasma arc melting method.

The melting step may be performed in an inert atmosphere at a temperature of 2200K to 2300K, for example, 2273K. The melting step may be performed for 30 minutes to 1 hour, for example, 30 minutes.

The step of melt spinning the melt to obtain an alloy ribbon may be performed by melt spinning at a temperature of 1800K to 1900K, for example 1873K, at a speed of 2500rpm to 3500rpm, for example, 3000rpm to obtain an alloy ribbon having a length of about 1 μm. have.

In the step of cold rolling the alloy ribbon, the alloy ribbon is pulverized into a powder state, and then cold-rolled at a temperature of 280K to 300K, for example, 295K under a load of 720MPa to 760MPa, for example, 749MPa.

After cold rolling, it may be sealed by putting it in a quartz tube under vacuum, and then heat treatment, for example, heat treatment at a temperature of 1000K to 1200K for 30 minutes to 2 hours, specifically at 1123K for 1 hour. After heat treatment, the resultant is water-cooled _{to obtain a ThMn 12} type magnetic material.

Through the cold rolling, an alloy substrate having a thickness of 1 mm to 5 mm, for example 3 mm, is obtained.

_{The ThMn 12} type magnetic body manufactured by the method according to an exemplary embodiment of the present invention has excellent magnetic properties and can be usefully used in various fields such as electric vehicle motors.

Hereinafter, examples will be described in detail to illustrate the present invention in detail. However, the embodiments according to the present invention may be modified in various forms, and the scope of the present invention is not construed as being limited to the embodiments described below. The embodiments of the present specification are provided to more completely describe the present invention to those of ordinary skill in the art.

Metal materials of the purity and particle diameter of Table 1 were used as raw materials, and the place of purchase was Taewon Science.

Element name water(%) Particle size (mm) Sm 99.9 1~6 La 99.9 1~3 Zr 99.5 1~4 Fe 99.99 5-15 Co 99.95 3 Ti 99.9 10

Example 1 (when x is 0.1 in Equation 1)

The metal materials of Table 1 were mixed in the amounts shown in Table 2 below.

The metal raw material mixture was put in a water-cooled copper crucible of an argon plasma arc melting apparatus (manufacturer name:LEYBOLD, model name: LK6/45), and melted at 2273K for 30 minutes in an argon atmosphere. Then, melt spinning was performed at a temperature of 1873 K at a rotational speed of 3000 rpm (39.27 m/s) using a melt spinning apparatus (manufacturer's name: Y&I Tech) to obtain an alloy ribbon having a length of 1 μm.

The obtained alloy ribbon was pulverized using an agate mortar to obtain an alloy powder having an average particle diameter of 75 μm. The alloy powder was cold-rolled at 295K under a load of 6 tons (749 MPa) using a hydraulic press (manufacturer name: CARVER, model name: #3925) to obtain an alloy substrate having a thickness of 3 mm. Then, the obtained alloy substrate was put in a quartz tube ^{under vacuum (10 -2 torr) and sealed.} After heat treatment at 1123K for 1 hour, it was termed with water to obtain a magnetic body.

Example 2 (when x is 0.3), Example 3 (when x is 0.4) and Comparative Example 1 (when x is 0), Comparative Example 2 (when x is 0.5), and Comparative Example 3 (x Is 0.7)

A magnetic body was obtained in the same manner as in Example 1, except that the metal materials of Table 1 were mixed in the amounts shown in Table 2 below.

Sm(g) La(g) Zr(g) Fe(g) Co(g) Ti(g) Total(g) Example 1 2.4375 0.1656 0.1087 5.8579 1.5455 0.5706 10.6858 Example 2 1.8281 0.4967 0.1087 5.8579 1.5455 0.5706 10.4076 Example 3 1.5234 0.6623 0.1087 5.8579 1.5455 0.5706 10.2685 Comparative Example 1 3.0469 - - 5.8579 1.5455 0.5706 11.0209 Comparative Example 2 1.2188 0.8279 0.1087 5.8579 1.5455 0.5706 10.1294 Comparative Example 3 0.6094 1.1591 0.1087 5.8579 1.5455 0.5706 9.8511

X-ray diffraction analysis XRD analysis (measurement equipment: D/MAX-2500V/PO, Rigaku; measurement conditions: Cu-K _α ray) of the magnetic body prepared in the above Examples and Comparative Examples was performed.

1 is an XRD pattern of _{ThMn 12} type magnetic bodies according to Examples 1, 2 and Comparative Examples of the present invention.

As can be seen in Figure 1, XRD analysis results, respectively, at 2θ values of 29.9°, 33.1°, 36.7°, 37.5°, 42.2°, 42.5°, 43.3°, 44.9°, 47.5° and 48.4°, respectively (211) , (311), (301), (002), (400), (321), (202), (330), (411), and (222) crystal planes can be seen showing diffraction peaks. It can be seen that the magnetic bodies of Examples and Comparative Examples are all tetragonal ThMn12 type magnetic bodies.

Magnetic properties of the magnetic bodies obtained according to Examples 1 to 3 and Comparative Examples 1 to 3 were investigated.

The magnetic properties were analyzed for coercivity, residual magnetization, saturation magnetization, and maximum energy properties, and the results are shown in Table 3 below.

The magnetic hysteresis curves of the magnetic materials prepared in the above Examples and Comparative Examples were measured with Lakeshore's VSM equipment at a temperature of 300K under a magnetic field of 2T.

Saturation magnetization
Ms(emu/g) Residual magnetization
Mr(emu/g) Coercivity
Hci(Oe) Energetic
(BH)max(MGOe) Example 1 106.01 48.39 1944 1.77 Example 2 99.21 62.2 3538.7 4.65 Example 3 114.25 36.66 1932.4 1.00 Comparative Example 1 115.73 22.5 803.73 0.33 Comparative Example 2 116.15 24.4 1051.5 0.40 Comparative Example 3 143.81 8.46 162.6 0.03

2 is a graph showing magnetic hysteresis curves at 295 K of magnetic materials manufactured according to Examples 1, 2, and Comparative Examples of the present invention.

As shown in FIG. 2, it can be seen that the magnetic bodies of Examples 1 and 2 of the present invention have higher coercive force and higher maximum energy than the magnetic bodies of Comparative Examples 1 to 3.

3(a) is a graph showing the degree of saturation magnetization of a magnetic material according to Examples 1, 2, and Comparative Examples of the present invention. It is a graph showing the degree of residual magnetization of the magnetic material.

4 is a graph showing the coercive force of magnetic materials according to Examples 1, 2, and Comparative Examples of the present invention.

5 is a graph showing the maximum energy product of magnetic materials according to Examples 1 and 2 and Comparative Examples of the present invention.

3 to 5, the magnetic body according to an exemplary embodiment of the present invention has a maximum of about 176% increase in residual magnetization, a maximum of about 340%, and a maximum energy value compared to the magnetic body of Comparative Example 1. It can be seen that an increase of about 1309%

Although the present invention has been described with reference to an embodiment shown in the drawings, this is only exemplary, and those of ordinary skill in the art will appreciate that various modifications and other equivalent embodiments are possible therefrom.

Claims (8)

_{ThMn 12} type magnetic body having the composition of the following formula 1:
[Equation 1]
(Sm _1-x La _x Zr _0.1 ) _a (Fe _(1-y) Co _y ) _b Ti _c
During expression
0.1 ≤ x ≤ 0.4, y = 0.2, 0.5 ≤ a ≤ 1.5, 5.0 ≤ b ≤ 18, 0.5 ≤ c ≤ 1.5.
The method of claim 1,
_{ThMn 12} type magnetic body with x of 0.3.
The method of claim 1,
Formula (Sm _0.6 La _0.3 Zr _0.1 )(Fe _0.8 Co _0.2 ) ₁₁ Ti A ThMn ₁₂ type magnetic material.
Mixing and then melting the raw material powder to prepare a melt;
Melt spinning the melt to obtain an alloy ribbon;
Cold rolling the alloy ribbon and then heat-treating the alloy ribbon; And
A method of manufacturing _{a ThMn 12-} type magnetic body according to any one of claims 1 to 3, comprising the step of water cooling the heat-treated resultant.
The method of claim 4,
The step of manufacturing a melt by melting is a method _{of manufacturing a ThMn 12-} type magnetic body performed by a plasma arc melting method.
The method of claim 4,
_{The step of preparing a melt by melting is a method of manufacturing a ThMn 12-} type magnetic material, which is performed in an inert atmosphere at a temperature of 2200K to 2300K.
The method of claim 4,
The step of cold rolling is a method of manufacturing _{a ThMn 12-} type magnetic body proceeding under a load of 720 MPa to 760 MPa.
The method of claim 4,
The heat treatment step is a method of manufacturing _{a ThMn 12-} type magnetic material performed at a temperature of 1000K to 1200K.

Images