JPH0257683B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a method for manufacturing a wound core made of an amorphous alloy material suitable for use in a high frequency region. [Technical background of the invention and its problems] Conventionally, switching regulators, etc.
Ni-Fe crystalline alloys such as permalloy and Sendelta have been widely used as materials for the iron cores of saturable reactors in magnetic amplifiers for equipment operating in the high frequency range of 50 kHz. However, in these alloy systems, the coercive force (Hc) is small in DC characteristics, and the squareness ratio (Br/B ₁ ,
Br: residual magnetic flux density, B (magnetic flux density in a magnetic field of ₁ :1 oersted) is large, but in the high frequency range, the coercive force is large and the hysteresis loss is large, so the temperature rise during operation is high, and it is difficult to incorporate it into the same device. For example, there was a risk that the performance of components such as diodes would deteriorate. For this reason, amorphous alloy materials composed of base materials such as Fe, Co, and Ni containing Si, B, etc. as amorphous elements have been developed to have excellent properties such as high magnetic permeability and low coercive force. It has recently attracted widespread attention because of its soft magnetic properties. However, not all of these amorphous alloy materials have a low coercive force in a high frequency region, and therefore do not have a small hysteresis loss. Furthermore, amorphous alloys are in a so-called metastable state, and there have been concerns about their thermal stability in view of changes over time. [Purpose of the Invention] The present inventors have conducted intensive research to manufacture a wound core made of an amorphous alloy material with a large squareness ratio and low coercive force. It has been found that a wound core with good characteristics can be obtained when heat treatment is performed, followed by a heat treatment step at 80 to 200° C. in an alternating current magnetic field as a magnetic property adjustment step. The present invention was made based on these findings, and provides a method for manufacturing a wound core made of an amorphous alloy material that has a high squareness ratio, low coercive force, and extremely high thermal stability. With the goal. [Summary of the Invention] That is, the method of the present invention comprises forming an amorphous alloy material into a wound core, performing a strain relief heat treatment, and then a heat treatment step at 80 to 200°C in an alternating current magnetic field as a magnetic property adjustment step. It is characterized by The reason why heat treatment in an alternating current magnetic field is adopted as the magnetic property adjustment step in the present invention is that heat treatment in a direct current magnetic field tends to increase the coercive force at high frequencies. This is because it leads to a decrease in efficiency. Note that an alternating magnetic field is usually a magnetic field from a commercial frequency.
Preferably in the 100KHz range. The strength of this magnetic field is 0.5
Ersted or higher is suitable. Also, increase the temperature to 80~
The reason for limiting the temperature to 200℃ is that below 80℃, the AC magnetic field has no effect, and above 200℃, Co and Fe or
This is because stronger induced magnetic anisotropy occurs due to Fe, Ni, etc., and the coercive force increases. The above heat treatment temperature range is close to the temperature inside the switching regulator during mounting, so its characteristics are extremely stable. Examples of the amorphous alloy material used in the present invention include Co-based, Fe-based, and Co-Fe-based. Particularly in the case of a Co system represented by the following formula, it is preferable to provide a quenching step before the heat treatment step in the alternating current magnetic field described above. (Co _1-a Fe _a M _b ) _100-xy Si _x B _y (However, in the formula, M is
Ti, V, Cr, Mn, Ni, Zr, Nb, Mo, Ru,
Hf, Ta, W, Re, at least one element selected from the group of rare earths, 0≦a≦0.1, 0≦b≦0.1,
20≦x+y≦30, 5≦x≦20, 5≦y≦25) In addition, in the Fe system expressed by the following formula, the Curie point is heated in a magnetic field of 40 oersted or less before the heat treatment process in the alternating current magnetic field mentioned above. It is more effective to perform high-temperature heat treatment at a temperature lower than or equal to the crystallization temperature. (Fe _1-c M _c ) _100-xy Si _x B _y (However, in the formula, M is Ni, Ti, V, Cr, Mn,
At least one element selected from the group of Zn, Nb, Mo, Ru, Hf, Ta, W, Re, and rare earth elements, and when M is Ni, 0.2≦c≦0.4, 20≦x+y
≦30, 5≦x≦20, 5≦y≦25, if M is other than Ni, 0.01≦c≦0.1, 15≦x+y≦25, 5≦x
≦20, 5≦y≦20) In other words, the amorphous alloy material is melted, rapidly cooled and formed into a wound core, and then heated for about 5 to 40 minutes at a temperature higher than the Curie temperature and lower than the crystallization temperature. After applying strain relief heat treatment, Co-based amorphous alloy materials are rapidly cooled and then heat-treated in an alternating current magnetic field, and Fe-based amorphous alloy materials are subjected to high-temperature heat treatment in a magnetic field and then heat treated in an alternating current magnetic field. It is desirable to carry out heat treatment. In the case of Co-based alloys in the present invention, Fe contributes to increasing the magnetic flux density and zeroing magnetostriction of the obtained alloy, and its composition ratio a is set in the range of 0≦a≦0.10. If a exceeds 0.10, the overall magnetostriction will increase and the coercive force will also increase, which is not preferable. M is involved in the thermal stability of the alloy, and its composition ratio b
is set in the range of 0≦b≦0.10. When b exceeds 0.10, it becomes difficult to make it amorphous. In particular, when M is Ni, Nb, Ta, Mo, Cr, V, or a combination thereof, the effect is large and useful. Si and B are elements contained for amorphization, and the composition ratio x of Si is set in the range of 5≦x≦20, and the composition ratio y of B is set in the range of 5≦y≦25. The total composition ratio x+y of B is set to 20≦x+y≦30.
When x+y exceeds 30, it becomes difficult to make the material amorphous, while when it is less than 20, the crystallization temperature becomes lower than the Curie temperature, making it difficult to obtain a low coercive force as a whole. In addition, in the Fe system, when M is Ni,
As the proportion of Ni increases, the saturation magnetic flux density decreases, and when this proportion is 0.3, the squareness ratio has the maximum value.
It decreases before and after that. Therefore, the Ni composition ratio c is 0.2
When ≦c≦0.4, preferably 0.25≦c≦0.35, an amorphous alloy material with relatively high saturation magnetic flux density and squareness ratio can be obtained. In addition, when M is other than Ni, the composition ratio c is similarly
0.01≦c≦0.1, preferably 0.02≦c≦0.07. Regarding Si and B, the reason is the same as mentioned above. In this case, x+y is preferably in the range of 15≦x+y≦25. [Embodiments of the Invention] Next, embodiments of the present invention will be described. Example 1 An amorphous alloy material consisting of (Co _0.91 Fe _0.06 Nb _0.03 ) ₇₅ Si ₁₅ B ₁₀ was made into a material with a width of 5 mm and a thickness of 15 μm by a single roll method.
It was formed into a tape shape. The crystallization temperature and Curie temperature of this amorphous alloy material are 543℃ and 543℃, respectively.
It was 324℃. The resulting tape was interlayer insulated with magnesium oxide powder and wound 20 times around a 25 mm diameter quartz tube to form a toroidal core. Next, the core was subjected to strain relief heat treatment in nitrogen at a temperature of 450°C for 10 minutes, and after being rapidly cooled to room temperature, it was heat treated in an alternating current magnetic field of 10 oersteds at each temperature shown in Fig. 1 for 1 hour. The obtained core was provided with primary and secondary windings, and an AC hysteresis curve at 50kHz was measured using an AC magnetic field measuring device under an external magnetic field of 1 oersted to determine the coercive force and squareness ratio. The results are shown in Figure 1. In the figure, the solid line represents the squareness ratio, and the dotted line represents the coercive force. Also, by applying these cores to the saturable reactor of a magnetic amplifier, find the efficiency η (output/input) of the switching regulator at 50kHz,
The results are shown in Figure 2. As is clear from Fig. 1 and Fig. 2, the 50kHz
The squareness ratio is improved by up to 6%, and the coercive force is 0.03.
It was found that when the reactor was applied as a saturable reactor, the efficiency was improved to 78%. Example 2 Amorphous alloy materials having various compositions shown in Table 1 were made into tape shapes by a single roll method. The width of each tape was about 5 mm, and the thickness ranged from 18 to 22 μm. These tapes were interlayer insulated with magnesium oxide powder and wound around a bobbin with a diameter of 20 mm to create a toroidal core. Next, this was subjected to strain relief heat treatment at an appropriate temperature below the crystallization temperature and above the Cuyuri temperature, respectively, and then the whole was put into water (25° C.) and rapidly cooled. after that
Heat treatment was carried out at 150°C for 1 hour in an alternating current magnetic field of 10 oersted. Primary and secondary windings were applied to the obtained core, and the hysteresis curve was measured using an AC magnetization measuring device under an external magnetic field of 1 oersted.
Coercive force and squareness were determined. Table 1 shows the information on amorphous alloy materials of each composition.
Shows the difference in squareness ratio and coercive force at 50kHz.
As is clear from Table 1, by using the method of the present invention, smaller coercive force and higher squareness ratio can be obtained in amorphous alloy materials of various compositions.

[Table] Next, Table 2 shows the AC magnetic properties at 50kHz of the amorphous alloy materials having several compositions shown in Table 1 in comparison with that of the 80% Ni-Fe alloy.

[Table] From this table, according to the method of the present invention, 80%Ni-Fe
A wound core with superior squareness and coercive force can be obtained compared to alloys. Example 3 A master alloy with a composition of (Fe _0.7 Ni _0.3 ) ₇₈ Si ₈ B ₁₄ was melted,
Diameter rotating at 2000rpm from a 5mm wide quartz nozzle
A tape-shaped amorphous alloy having a width of 5 mm and a thickness of 17 μm was obtained by ejecting it onto a 30 cm roll. Next, this tape was wound around a toroidal core and then heated at 420℃ in a vacuum.
After performing strain relief heat treatment for 5 minutes, heat treatment was performed for 30 minutes at 390° C. in a magnetic field of 4 oersted in a vacuum. Thereafter, heat treatment was performed for 1 hour at each temperature shown in FIG. 3 in an alternating current magnetic field of 10 oersted. Primary and secondary windings were applied to the obtained core, and an AC hysteresis curve at 20kHz was measured using an AC magnetization measuring device under an external magnetic field of 1 oersted to determine the coercive force and squareness ratio. The results are shown in FIG. In addition, these cores are applied to the saturable reactor of a magnetic amplifier, and the efficiency η (output/input) of the switching regulator at 20kHz and the temperature rise ΔT of the core during operation are calculated, and the results are used in the fourth section. Shown in the figure. As is clear from the figure, the squareness can be improved by up to 3.5% by heat-treating the amorphous alloy material to remove strain, heat-treating it at a high temperature of 390°C, and then heat-treating it in an alternating magnetic field at a predetermined temperature range. , the coercive force is
When applied as a saturable reactor, the efficiency was improved to 77.5%, and the core temperature rise was also reduced by about 10°C. In addition, in order to confirm the effectiveness of the present invention (Fe _0.7
Table 3 shows a comparison of the magnetic properties at 20 kHz of the Ni _0.3 ) ₇₈ Si ₈ B ₁₄ amorphous alloy material and the 50% Ni-Fe alloy.

[Table] In Table 3, the saturation magnetic flux density B of the (Fe _0.7 Ni _0.3 ) ₇₈ Si ₈ B ₁₄ amorphous alloy material and 50% Ni-Fe are both 11 KG or more, and the squareness ratio is also 95%.
The above is practically effective. Regarding coercive force (Fe _0.7 Ni _0.3 ) ₇₈ Si ₈ B ₁₄ amorphous alloy material has 50
%Ni-Fe alloy, less than half that, and is very effective in practice. In addition, in order to confirm the effectiveness of these materials in magnetic amplifier cores, each alloy was used as a high-frequency core. The result (Fe _0.7 Ni _0.3 )
₇₈ Si ₈ B ₁₄ has a power efficiency of 2.5 compared to 50Ni-Fe alloy.
%, and the temperature rise of the iron core during operation was reduced by 25℃. Furthermore, when used in a magnetic amplifier for a switching regulator, the characteristics were good and the diode was not destroyed due to temperature rise. Example 4 A master alloy with a composition of (Fe _0.96 Nb _0.04 ) ₈₂ Si ₅ B ₁₃ was melted and sprayed from a 5 mm wide quartz nozzle onto a 30 cm diameter roll rotating at 2000 rpm to form a 5 mm wide and 20 μm thick roll.
A tape-shaped amorphous alloy was obtained. This tape was then wound around a toroidal core, subjected to strain relief heat treatment at 450°C for 30 minutes in an inert gas atmosphere, and then heat treated in a magnetic field of 20 oersteds just below the Curie temperature.
It was applied for 30 minutes. Thereafter, heat treatment was performed at 180° C. for 2 hours in an alternating current magnetic field of 20 oersted. Before and after this heat treatment, primary and secondary windings were applied to the core, and an AC hysteresis curve at 20kHz was measured using an AC magnetization measuring device under an applied magnetic field of 1 oersted to determine the coercive force and squareness. The results are shown in Table 4.

[Table] In order to confirm the effectiveness of these cores as magnetic amplifiers, we applied them to a switching regulator. As a result, the efficiency of the core treated with the heat treatment of the present invention was improved by 2%, and the temperature of the core during operation increased by 15℃.
We were able to reduce this. Furthermore, the same heat treatment was performed for each composition shown in Table 5. The improved values of coercive force and squareness ratio before and after the heat treatment are shown.

【table】

[Table] As is clear from this table, by using the method of the present invention, a smaller coercive force and a higher squareness ratio can be obtained in amorphous metals of various compositions. Example 5 The cores used in Example 1 and Example 3 were incorporated into switching power supplies operating at 50 KHz and 20 KHz, respectively, and subjected to actual aging at 150°C. The results are shown in FIG. 5 regarding the power supply efficiency, and it can be seen that in all cases the values are extremely stable, indicating that the reactor has excellent characteristics as a saturable reactor. In addition, in FIG. 5, 1 is for Example 1, and 1 is for Example 3.
3 indicates that. [Effects of the Invention] As explained above, according to the method of the present invention, a wound core having a high squareness ratio and a low coercive force can be obtained. Therefore, the temperature rise during operation is relatively low, and there is no risk of deteriorating the performance of components incorporated in the same device. Therefore, it is effective as a wound core for various saturable reactors, etc., especially in high frequency ranges, and is particularly effective as a wound core for magnetic amplifiers for switching regulators.

[Brief explanation of drawings]

Figures 1 and 3 are graphs showing changes in squareness ratio and coercive force when the temperature of heat treatment in an alternating magnetic field is changed, and Figure 2 is a graph showing the changes in squareness ratio and coercive force when the temperature of heat treatment in an alternating current magnetic field is changed. Figure 4 is a graph showing the efficiency η at 50kHz of a switching regulator when applied to a saturable reactor of a magnetic amplifier. Angular regulator
It is a graph showing the efficiency η at 20kHz and the temperature rise ΔT of the core during operation. FIG. 5 is a graph showing power supply efficiency when a wound core is incorporated into a switching power supply and aging is performed.

Claims (1)

[Claims] 1. Amorphous alloy material is formed into a wound core, subjected to strain relief heat treatment, and then includes a heat treatment step at 80 to 200°C in an alternating current magnetic field as a magnetic property adjustment step. Manufacturing method of wound iron core. 2 The amorphous alloy material is (Co _1-a Fe _a M _b ) _100-xy Si _x B _y (where M is Ti, V, Cr, Mn, Ni, Zr,
At least one element selected from the group of Nb, Mo, Ru, Hf, W, Ta, Re, and rare earth elements, 0≦a
≦0.1, 0≦b≦0.1, 20≦x+y≦30, 5≦x
20, 5≦y≦25) The method for manufacturing a wound core according to claim 1. 3. The method for manufacturing a wound core according to claim 2, wherein a quenching step is provided as a magnetic property adjustment step before the heat treatment step in an alternating current magnetic field. 2 The amorphous alloy material is (Fe _1-c M _c ) _100-xy Si _x B _y (where M is Ni, Ti, V, Cr, Mn, Zn,
At least one element selected from the group of Nb, Mo, Ru, Hf, W, Ta, Re, and rare earth elements, and when M is Ni, 0.2≦c≦0.4, 20≦x+y≦
30, 5≦x≦20, 5≦y≦25, 0.01≦c≦0.1 when M is other than Ni, 15≦x+y≦25, 5≦x≦
20, 5≦y≦20) The method for manufacturing a wound core according to claim 1. 5. The method for manufacturing a wound core according to claim 3, wherein a high temperature heat treatment step in a magnetic field is provided as a magnetic property adjustment step before the heat treatment step in an alternating current magnetic field.