JPH10324961A - Iron-based amorphous alloy sheet strip excellent in soft magnetic property, and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the iron-based amorphous alloy thin strip excellent in the soft magnetic property by proceeding the structural mitigation of the amorphous alloy sheet strip containing Fe, B, Si, Mn, Co, Ni, and Cr by the prescribed quantity at the temperature lower than the crystallization temperature by the prescribed value. SOLUTION: The alloy has the chemical formula indicated by Fex By Siz Ma , where M is one or more kinds of metal to be selected among Mn, Co, Ni and Cr, and x; 77-82 (at%), y; 9-17 (at%), z; 5-14 (at%), a; 0.2-1.0 (at%). The molten alloy is rapidly solidified to form an amorphous alloy thin strip. The amorphous sheet strip is heat treated at the temperature lower than the crystallization temperature by 300-400 deg.C for >=6 hours. Then, the high-temperature annealing is achieved in the magnetic field according to the established method. The low-temperature heat treatment promotes the structural mitigation of the amorphous alloy sheet strip, and improves the soft magnetic property. In the relationship between the heat treatment temperature and the iron loss13/50 , the reduction effect of the iron loss is remarkably demonstrated at the temperature lower than the crystallization temperature Tx by 300-400 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an iron-based amorphous alloy ribbon having excellent soft magnetic properties and a method for producing the same.

[0002]

2. Description of the Related Art As a method of producing an iron-based amorphous alloy, for example, Japanese Patent Publication No. Hei 2-11662 discloses a method in which a molten ribbon of Fe-Si-B is made into an amorphous ribbon by a liquid quenching method, and then is heated in a magnetic field. 340-
A method of annealing at a temperature of 440 ° C. has been proposed.

[0003] Also, in Japanese Patent Application Laid-Open No. 5-78796, Sn
In order to form a Sn segregation layer by adding Sn to the surface layer of an amorphous alloy ribbon to increase the crystallization resistance of the surface layer and to form such a Sn segregation layer. ℃ temperature
A method of holding for 0.5 to 1000 hours has been proposed.

[0004]

However, the conventional amorphous alloy ribbon as described above has a problem that although the iron loss is improved to some extent, it is still insufficient. In addition, the addition of Sn has a problem that it is difficult to add Sn in a molten metal because the difference in melting point with iron as the main component is as large as 1000 ° C. or more. An object of the present invention is to solve the above-mentioned problem advantageously, and an object of the present invention is to propose an iron-based amorphous metal ribbon with further improved soft magnetic properties as well as an advantageous production method thereof.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to achieve the above object, and as a result, have found that Fe-B-
Si-based amorphous alloys contain a small amount of transition metals, such as Mn, Co, Ni, and Cr, which are close to iron, and introduce structural relaxation at a relatively low temperature, 300-400 ° C lower than the crystallization temperature. By doing so, it has been found that the amorphous state can be made more advantageous for the soft magnetic properties, and thus the advantageous improvement of the soft magnetic properties is realized. The present invention is based on the above findings.

Namely, the present invention has the _{formula: Fe x B y Si z M} a wherein M: Mn, Co, 1 or more kinds selected from among Ni and Cr x: 77~82 (at%) y: 9 to 17 (at%) z: 5 to 14 (at%) a: An amorphous alloy ribbon having a composition represented by 0.2 to 1.0 (at%), This is an iron-based amorphous alloy ribbon excellent in soft magnetic characteristics, characterized by promoting structural relaxation at a temperature lower by 300 to 400 ° C than the crystallization temperature.

Further, the present invention has the _{formula: Fe x B y Si z M} a wherein M: Mn, Co, 1 or more kinds selected from among Ni and Cr x: 77~82 (at%) y: 9 to 17 (at%) z: 5 to 14 (at%) a: An alloy melt having a composition of 0.2 to 1.0 (at%) is rapidly solidified to form an amorphous alloy ribbon. The amorphous alloy ribbon is subjected to a low-temperature heat treatment at a temperature lower than its crystallization temperature by 300 to 400 ° C. for 6 hours or more, and then subjected to a high-temperature annealing in a magnetic field according to a conventional method, and thus has excellent soft magnetic properties. This is a method for producing an iron-based amorphous alloy ribbon.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. First, the reason why the composition of the alloy is limited to the above range in the present invention will be described. Fe: 77 to 82 at% If the Fe content is less than 77 at%, the magnetic flux density is reduced, which is not practical. On the other hand, if it exceeds 82 at%, not only iron loss increases but also thermal stability deteriorates. , Fe content is 77-82at
%.

B: 9 to 17 at% If the B content is less than 9 at%, it becomes difficult to form an amorphous phase, while if it exceeds 17 at%, the Curie temperature becomes too low. Therefore, the B content is limited to the range of 9 to 17 at%.

Si: 5 to 14 at% When the Si content is less than 5 at%, the Curie temperature becomes too low. On the other hand, when the Si content exceeds 14 at%, not only the iron loss increases, but also the magnetic flux density decreases. Limited to the range of ~ 14at%.

M: 0.2 to 1.0 at% Here, M is one or more selected from Mn, Co, Ni and Cr. These Mn, Co, Ni,
The reason why the lower limit of the Cr content is set to 0.2 at% is that the effect of the present invention of improving the soft magnetic properties due to structural relaxation at a low temperature will not be exhibited without further addition, and the upper limit is set to 1.0 at%.
The reason is that the effect of the present invention does not appear even more than that. More preferably, it is 0.3 to 0.6 at%.

Next, the manufacturing process of the present invention will be described. In the present invention, after rapid solidification, prior to high-temperature annealing in a magnetic field according to a conventional method, the crystallization temperature is set to 300 to 400 ° C.
The heat treatment is performed at a low temperature, and this low-temperature heat treatment is the greatest feature of the present invention. By performing such a low-temperature heat treatment, the structural relaxation of the amorphous alloy ribbon is promoted, and thus the soft magnetic properties are improved. It is. Here, the reason why the heat treatment temperature after the rapid solidification was limited to a temperature range lower by 300 to 400 ° C. than the crystallization temperature is that the effect of the present invention described above is sufficient even at a temperature lower than the range or higher than the range. Is not expressed.

[0013] Figure _{1, Fe 79 B 12 Si 8.5} Mn obtain a composition of _0.5 amorphous alloy ribbon (crystallization temperature T _X: 535 ℃) and after rapid solidification, after heat treatment at various temperatures, atmospheric Temperature and Iron Loss W in High Temperature Annealing in a Magnetic Field
_The result of examining the relationship with _13/50 is shown. As is clear from the figure, the effect of reducing iron loss is remarkably exhibited when the heat treatment temperature is lower by 300 to 400 ° C. than the crystallization temperature T _X.

The reason why the heat treatment time is set to 6 hours or more is that the treatment time of less than 6 hours is not sufficient for the structural relaxation at such a low temperature, and the effect of the present invention is as good as expected. Is not obtained. FIG. 2 shows that Fe ₇₉
The heat treatment temperature of the amorphous alloy ribbon with a composition of B ₁₂ Si _8.5 Mn _0.5 is fixed at 150 ° C (385 ° C lower than the crystallization temperature), and the treatment time and iron loss when various times are maintained. The result of examining the relationship with _{W13 / 50} is shown. As shown in the figure, by setting the treatment time to 6 hours or more, a remarkable improvement in iron loss characteristics is achieved. Note that 24
Almost no change in iron loss was observed up to 0 hours.

After the above-mentioned low-temperature heat treatment, annealing in a magnetic field is performed at a high temperature according to a conventional method, and the strength of the applied magnetic field in such annealing is preferably 10 Oe or more. The annealing temperature is preferably set to about 350 to 450 ° C. The reason is that if the annealing temperature is lower than 350 ° C, the strain existing in the ribbon cannot be sufficiently removed, so that satisfactory magnetic properties cannot be obtained, while if it exceeds 450 ° C, the temperature approaches the crystallization temperature,
This is because the magnetic properties deteriorate.

[0016]

EXAMPLE An alloy melt having various component compositions shown in Table 1 was injected onto the surface of a high-speed rotating Cu alloy roll and rapidly solidified to form an amorphous alloy thinner having a thickness of 25 μm and a width of 20 mm. Obi was manufactured. Then, the obtained ribbon was heat-treated at a temperature of 150 to 200 ° C. for 12 hours in an inert atmosphere,
Annealing in a magnetic field was performed in an inert atmosphere while applying a magnetic field of 20 Oe in the longitudinal direction at 410 ° C. Table 1 also shows the measurement results of the iron loss and the magnetic flux density of the ribbon thus obtained. For comparison, the results of investigations on the magnetic properties of the ribbons obtained by omitting the heat treatment at 150 to 200 ° C. are also shown.

[0017]

[Table 1]

As shown in Table 1, after rapid solidification, prior to high-temperature annealing in a magnetic field according to a conventional method, heat treatment is performed at a low temperature of 150 to 200 ° C., thereby significantly improving the magnetic properties of the ribbon, particularly the iron loss properties. Have been.

FIG. 3 shows a heat treatment at a low temperature (150 ° C., 6 hours).
Changes in the thermal state generated in the amorphous ribbon by DSC
The results are shown by specific heat measurement by a (differential scanning calorimeter). The figure also shows, for comparison, the results of measurements on an as-cast ribbon and a ribbon annealed in an inert gas at 375 ° C. for 2 hours in a magnetic field. The horizontal axis represents the measured temperature and the vertical axis represents the specific heat. The specific heat was measured from room temperature to 600 ° C. while heating at a heating rate of 40 ° C./min.
As shown in the figure, the specific heat curve of the 150 ° C treated material almost matches that of the as-cast material, but the measured temperature
The specific heat of the 150 ° C treated material increased from 150 ° C to about 250 ° C. This is 1
The state treated at 50 ° C. indicates that the structural relaxation is advanced even in the same amorphous state.

Also, comparing the results of the 375 ° C treated material with the 150 ° C treated material,
Although the treated material has a higher specific heat, it has the same specific heat again at a temperature of 510 ° C. or higher, and the specific heat drops sharply due to heat generated by crystallization from the material itself. It can be seen that the change in the microscopic structure from the as-cast condition was larger at the 375 ° C treatment. However, from 150 ℃ to 200 ℃
During the heat treatment, the specific heat of the 150 ° C treated material was higher than that of the 375 ° C treated material.
It is known that it does not disappear even after the treatment at 75 ° C. That is, although the change caused by the low-temperature heat treatment is small compared to the change caused by the high-temperature heat treatment, the history remains even after the high-temperature heat treatment, and as a result, the magnetic properties are improved. This is presumed to be due to the fact that the short-range order between the iron atom and the transition metal atom is changed by the low-temperature treatment, and the change is maintained even in the subsequent high-temperature treatment, so that the magnetic properties are improved.

[0021]

Thus, according to the present invention, Fe-B-
The soft magnetic properties of the Si-based iron-based amorphous alloy ribbon can be remarkably improved as compared with the conventional one.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the heat treatment temperature of an amorphous alloy ribbon having a composition of Fe ₇₉ B ₁₂ Si _8.5 Mn _0.5 and the iron loss W _13/50 .

FIG. 2 is a graph showing the relationship between the heat treatment time of an amorphous alloy ribbon having a composition of Fe ₇₉ B ₁₂ Si _8.5 Mn _0.5 and the iron loss W _13/50 .

FIG. 3 is a graph showing a change in specific heat due to heat treatment of an amorphous alloy ribbon having a composition of Fe ₇₉ B ₁₂ Si _8.5 Mn _0.5 .

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C22F 1/00 691 C22F 1/00 691C H01F 1/153 C22C 33/02 Z // C22C 33/02 H01F 1/14 C

Claims (2)

[Claims] 1. A chemical _{formula: Fe x B y Si z M} a wherein M: Mn, Co, 1 or selected from among Ni and Cr or two or more x: 77~82 (at%) y : 9~ 17 (at%) z: 5 to 14 (at%) a: An amorphous alloy ribbon having a composition represented by 0.2 to 1.0 (at%), which is obtained from the crystallization temperature of the amorphous alloy ribbon. An iron-based amorphous alloy ribbon with excellent soft magnetic properties characterized by advanced structural relaxation at a temperature lower by 300 to 400 ° C. 2. A chemical _{formula: Fe x B y Si z M} a wherein M: Mn, Co, 1 or selected from among Ni and Cr or two or more x: 77~82 (at%) y : 9~ 17 (at%) z: 5 to 14 (at%) a: An alloy melt having a composition represented by 0.2 to 1.0 (at%) is rapidly solidified to form an amorphous alloy ribbon, and then the amorphous alloy is formed. An iron-based alloy having excellent soft magnetic properties, characterized in that a ribbon is subjected to a low-temperature heat treatment at a temperature of 300 to 400 ° C. lower than its crystallization temperature for at least 6 hours and then subjected to a high-temperature annealing in a magnetic field according to a conventional method. Method for manufacturing amorphous alloy ribbon.