JPS625989B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for heat treating an amorphous magnetic alloy material. More specifically, it is a heat treatment method that can increase the magnetic permeability of amorphous magnetic alloy materials, especially thin plates thereof, and reduce magnetic loss, and is a method for producing large quantities of such materials with good magnetic properties at once. Regarding how it can be obtained. Fe-Si alloys, Fe-Ni alloys, Fe-Al alloys, Fe-Si-Al alloys, etc. have been known as high permeability magnetic alloy materials with crystal structures, and there are many types depending on their characteristics. used in the field.
However, these crystalline magnetic alloys still have property and usage drawbacks. Among these, sendust, which is an Fe-Si-Al alloy, has a high magnetic permeability and contains approximately 10% Si, but it has the disadvantage that it cannot be plastically worked. Therefore, its use is limited to special applications where its high hardness is utilized, such as magnetic head elements for VTRs, and is only used after special processing. Moreover, the frequency characteristics of magnetic permeability are also not satisfactory. In addition, permalloy alloys are used as iron cores for various types of light electrical equipment, but the manufacturing method is
It has the drawbacks of requiring a very large number of steps and being expensive. Furthermore, its saturation magnetic flux density is low, limiting its use. Under these circumstances, it is desired to develop a magnetic alloy material that has excellent properties and has no disadvantages in use. Among these, amorphous magnetic alloys have recently attracted much attention and are being actively researched. In the solid state, metals usually exist as crystals in ^which atoms are arranged in an ordered ^state .
When solidified by cooling at a high rate of sec, an amorphous alloy with an atomic arrangement similar to that in the molten state is obtained even in the solid state. Even by X-ray diffraction or electron beam diffraction, this amorphous alloy does not show a diffraction image showing a crystalline structure, and has an atomic arrangement that does not have long-range regularity, which is structurally different from crystalline alloys. It is something that you have. Magnetic materials made of such amorphous alloys do not have magnetocrystalline anisotropy unlike ordinary crystalline materials, and especially transition metal-metalloid amorphous alloys have a small coercive force (Hc). It is expected to have excellent soft magnetic properties, and has excellent properties as a soft magnetic material, such as high electrical resistance, high hardness, good workability in thin plate processing, etc., and easy and inexpensive manufacturing method. It also has advantages in use. Conventionally, such amorphous magnetic alloys contain Fe, Co, and Ni as transition metal components, and Si,
Those containing metalloid components such as B, C, and P are known. These have properties depending on their composition, and their uses can be considered depending on their properties, and some of them have been put into practical use. Among these, Fe-based transition metals containing Fe as a main component have large magnetostriction, but are suitable for use as transformer materials because of their large saturation magnetic flux density (Bs) and low cost. Co-based materials, which have Co as the main component as a transition metal, have lower Bs than Fe-based materials and are more expensive, but because they provide a composition with zero magnetostriction, they are suitable for magnetic head materials. Ni-based materials containing more than a certain amount of Ni have Ni replacing Fe and Co to some extent, so their magnetic permeability is higher than the first two, but their Bs is lower than the first two, so their practical use is not expected. Not yet. As described above, amorphous magnetic alloys with various compositions are known, but one has emerged that greatly exceeds crystalline magnetic alloys in both magnetic permeability and saturation magnetic flux density. The reality is that there is not. For this reason, if magnetic alloys with these compositions can be made amorphous and then subjected to some kind of treatment to increase their magnetic permeability and reduce magnetic loss,
It has become more desirable as a material for magnetic heads, a transformer material, etc., and the development of such technology is expected. One such technique that has been conventionally used is heat treatment. This heat treatment is performed on an amorphous thin plate after obtaining an amorphous thin plate by ultra-quenching from the liquid phase. (Tcry) or lower, and then cooled. This removes internal strain during thin plate manufacturing by ultra-quenching, and increases magnetic permeability. However, this heat treatment
The disadvantage is that it cannot be applied to Tcry alloys. In general, Tc and Bs have a positive correlation, and in particular, in Co-based alloys with zero magnetostriction, 1000Oe
Tc at a saturation magnetic flux density of 10kG, which is the minimum required for a magnetic head for recording on high coercivity media of
is almost equal to Tcry, and there is a drawback that it cannot be used as a technique for improving the magnetic permeability of alloys with higher saturation magnetic flux density. Also, conversely, Tc＜Tcry
In order to obtain a large magnetic permeability when the Tc becomes large for this alloy, it is necessary to rapidly cool it after heat treatment or to perform complicated cooling temperature control. Although such heat treatment does improve the magnetic permeability of alloys with Tc < Tcry, internal strain occurs during cooling, and as a result, the initial magnetic permeability in particular is lower than that of conventional crystalline alloys. However, it is not possible to obtain particularly good values. It has also been found that this internal strain causes a change in magnetic permeability over time. Therefore, such heat treatment techniques are not effective. In contrast, a technology was developed in which a thin plate obtained by ultra-quenching was heat-treated in a magnetic field.
This is disclosed in Publication No. 73923, Publication No. 52-114421, etc., and it is stated that the maximum magnetic permeability μm is significantly improved by heat treatment in a magnetic field. In this case, the heat treatment temperature is below the crystallization temperature, and the magnetic field is applied as a static magnetic field only from a fixed magnetic field axis direction. In this way, when a magnetic field is applied from a certain direction during heat treatment, induced magnetic anisotropy occurs in the amorphous magnetic alloy thin plate with the easy axis in the direction of magnetic field application. In such a case, magnetization tends to be oriented along the induced easy axis of magnetization, and therefore the residual magnetic flux density (Br) increases. If a magnetic field is applied in the opposite direction at this time, the magnetization and the energy of the magnetic field are reduced, so the 180° domain wall moves, easily causing magnetization reversal, and the coercive force (Hc) becomes small.
Therefore, as mentioned above, the residual magnetic flux density (Br) increases, so the maximum magnetic permeability μ as a static magnetization characteristic increases.
It is natural that m〓Br/Hc increases.
However, when such heat treatment in a magnetic field was performed and the magnetic properties were measured, it was confirmed that the magnetic permeability under alternating current conditions decreased. In other words, the initial magnetic permeability decreases, and the magnetic permeability (μ ₁₀ ) under a magnetic field of about 10 mOe decreases.
It also does not increase significantly. The present inventor conducted various studies in order to investigate the cause of the inconvenience caused by such conventional heat treatment in a magnetic field. As a result, the following was found. That is,
In conventional heat treatment in a magnetic field, a magnetic field is applied from a fixed direction, so that the axis of easy magnetization is induced as described above. In this case, when the magnetic field is changed quasi-statically, the magnetic permeability is not affected by the moving speed (V) of the domain wall. A high μm is therefore obtained. However, magnetic permeability under an alternating magnetic field depends on the moving speed of the domain wall and is approximately proportional to it. Also, the braking coefficient (β) that reduces this moving speed is proportional to the square root of the magnetic anisotropy (K). Therefore, when an easy axis of magnetization is induced in a thin plate by heat treatment in a magnetic field and anisotropy is generated, the domain wall movement speed decreases, and the magnetic permeability under an alternating magnetic field, that is, the dynamic characteristic value of magnetic permeability, especially the initial permeability. The magnetic flux decreases. Therefore, based on this knowledge, the present inventors
In order to eliminate the disadvantages of conventional heat treatment in a magnetic field, we first performed heat treatment below the Curie point of an amorphous magnetic alloy.
Furthermore, they have proposed a heat treatment method in which a magnetic field is applied while rotating while heating and maintaining the temperature at a temperature below the crystallization temperature. According to this heat treatment method, the magnetic anisotropy induced in the thin plate becomes isotropic.
Since the direction of the component of the applied magnetic field in the direction of the thin plate surface is rotated by one rotation, magnetic anisotropy does not exist locally, and accordingly, the damping coefficient of domain wall movement decreases, and locally there is no anisotropy. As a result, it becomes easier to form a reflux magnetic domain structure, and the dynamic characteristic values of magnetic permeability, especially the initial magnetic permeability, are not only prevented from decreasing, but are significantly improved, and their static characteristic values are also significantly improved. . Furthermore, magnetic loss is also significantly reduced. The present invention relates to an improvement on the previous proposal of the present inventors, and in the previous proposal,
Varying the applied magnetic field such that the induced magnetic anisotropy induced by the applied magnetic field is isotropic, thereby improving the dynamic and static characteristic values of magnetic permeability,
In addition, by utilizing the principle of reducing magnetic loss, the effect is equally achieved, and
The main purpose is to provide a concrete method that can process large quantities of the same. The present inventor has completed the present invention as a result of conducting various studies for this purpose. That is, the present invention provides a heat treatment method for an amorphous magnetic alloy material in which at least two external magnetic fields are applied to the material while the material is heated and maintained at a temperature below the Curie point of the amorphous magnetic alloy and below its crystallization temperature. Applied almost linearly from two or more directions, at that time,
The purpose is to rotate the direction of the composite magnetic field of the plurality of external magnetic fields so that the magnetic anisotropy induced in the material by the composite magnetic field becomes isotropic, and then cool it. According to the present invention, the magnetic properties of the amorphous alloy material obtained in exactly the same manner as the inventor's previous proposal are improved. That is, compared to the heat treatment in the absence of a magnetic field, the static and dynamic characteristic values of magnetic permeability are significantly improved. Furthermore, magnetic loss is also significantly reduced. In addition, unlike heat treatment in a magnetic field where a magnetic field is applied from a fixed direction, the dynamic characteristic value of magnetic permeability, especially the initial permeability, does not decrease.On the contrary, the dynamic characteristic is significantly improved, and the magnetic Losses are also reduced.
Therefore, the restrictions on the composition of amorphous alloys, which have hitherto been limited depending on the application, are relaxed, and as a result, it becomes possible to create practical materials with excellent properties for a variety of applications. In addition, internal strain during material manufacturing can also be effectively removed. Furthermore, the present invention can be applied to alloys where Tc>Tcry, and as a result, it is possible to obtain high magnetic permeability and low magnetic loss. For this reason, particularly for Co-based amorphous alloy materials with low magnetostriction, extremely excellent properties in practical use such as high saturation magnetic flux density and high magnetic permeability, which are higher than those of Sendust alloy, can be obtained. Also, for alloys where Tc<Tcry, slow cooling is possible after heat treatment, so the magnetic permeability is significantly improved. Furthermore, embrittlement and oxidation occur with materials with a high Tc, but in the present invention, the heat treatment can be performed at a relatively low temperature below Tc, so embrittlement does not occur, and it can be carried out in air. No oxidation occurs either. Note that the effect of significantly improving magnetic permeability and magnetic loss is an effect unique to amorphous magnetic alloys, and even if the present invention is applied to crystalline magnetic alloys, K ₁ or K Either of ₂
There is a magnetocrystalline anisotropy of about 10 ² erg/cm ² , and even if this value is small, the microscopic directionality due to the crystalline structure cannot be removed and such an effect cannot be expected. In the present invention, in addition to realizing all the effects related to the improvement of magnetic properties based on the previous proposal of the present inventors, it is also possible to apply the treatment to a large amount of materials at once. That is, it is possible to easily adopt a configuration in which the heat treatment of the present invention is performed while continuously moving an amorphous magnetic alloy material, particularly a thin plate, in a fixed direction. The present invention will be explained in detail below. The present invention is applicable to approximately all substantially amorphous magnetic alloy materials. However, in order to apply the present invention and obtain desirable characteristics as various practical materials, it is preferable that the material has a composition represented by the following formula. Formula MpTq Here, M represents 1 to 3 of Fe, Co, and Ni with a total of 1 mol, and T represents 1 to 4 of Si, B, P, and C with a total of 1 mol. Also, the sum of p and q is
100at%, and q is 10 to 50at%. Among these, those having the composition shown by the following formula are particularly preferred. Formula (Fe _a Co _b Ni _c ) _x (Si _e Bf) _f where x and y are positive numbers, a, b, c and e are 0 or positive numbers, f is a positive number and a+b
+c=1, e+f=1, x+y=1000≦ax≦
85, 0≦bx≦85, ax＋bx≠00≦cx≦50, 10≦y
There is a relationship of ≦50. In this case, in the composition shown by the above formula, the semimetal component consisting of silicon and boron accounts for 50 at% or less of the total amount of phosphorus and/or It may be substituted with carbon. In addition, in the amorphous magnetic alloy having the composition shown by the above formula, Ti, Ti,
Zr, V, Nb, Ta, Cr, Mo, W, Zr, Al, Ga,
One or more of In, Ge, Sn, Pb, As, Sb, Bi, Gd, etc. may be contained. The reason why the composition represented by the above formula is particularly preferable is as follows. First, Fe and Co in the composition exhibit ferromagnetism at room temperature, and on the other hand, a metalloid component is required for amorphization. It is preferable that When Fe and/or Co are replaced with Ni, the saturation magnetic flux density and the Curie point decrease. Therefore, Ni
It is preferable that the amount cx added is 0 to 50 at%.
The semimetallic components of Si and B are elements that promote the amorphization of the alloy, but the semimetallic components are 10%, especially 15at.
When it is less than %, and when it is more than 50%, especially 33%, it becomes difficult to make it amorphous, so y is
It is preferably 10 to 50 at%, more preferably 15 to 33 at%. Also, regarding the ratio of Si and B, Si
If e is larger than 70 at%, it becomes difficult to make it amorphous, so e is preferably in the range of 0 to 70 at%. An alloy material having such a composition can be obtained by ultra-quenching from the liquid phase. In order to obtain an amorphous magnetic alloy material by ultra-quenching from the liquid phase, an alloy of the corresponding composition is melted to form a melt, and this melt is heated from the molten state to approximately 10 ⁴ °C/sec or more, usually 10 ⁴ This may be achieved by ultra-rapid cooling at a cooling rate of ~10 ⁶ °C/sec and cooling solidification. In order to ultra-quench the molten alloy liquid, various methods such as the known twin-roll method, single-roll method, or inside-in-division method may be used. Therefore, the melting conditions for the alloy, the jetting conditions for the alloy liquid, the shape and dimensions of the nozzle during jetting, the shape, dimensions, material, etc. of the cooling body such as twin rolls are within the range of conditions for the known ultra-quenching method. It may be determined as appropriate. Furthermore, when melting the alloy, it is preferable to carry out the process in an inert gas such as argon, or while an inert gas is flowing in. However, the spouting of this melt can be carried out in either an inert gas or air atmosphere. You may go against them. Although such an amorphous magnetic alloy material may have various shapes, such as a thin wire, it is generally used as a thin plate. The thin plate generally has a thickness of about 5 to 200 μm, particularly 20 to 60 μm, and the shape of the thin plate can be any shape, and the dimensions of the thin plate are as follows in the present invention: Since it is possible to perform so-called batch processing on a thin plate formed into a predetermined shape, or to perform continuous processing while continuously moving a long continuous thin plate, various types of processing can be performed. In the present invention, such an amorphous magnetic alloy material is subjected to a predetermined treatment. In this process, the amorphous magnetic alloy material must be kept below the crystallization temperature of the amorphous magnetic alloy. This is because the properties as an amorphous magnetic alloy are lost. At the same time, its holding temperature must be below the Curie point. This is because spontaneous magnetization does not occur above the Curie point and induced magnetic anisotropy does not occur. On the other hand, the lower limit of the holding temperature is generally 100°C or higher, more preferably 150°C or higher. Further, the holding time is generally within 500 hours, preferably about 1 minute to 500 hours. As a heating method, in addition to performing in a resistance type electric furnace, high frequency heating, infrared heating, and various other methods are possible. In the present invention, a continuous thin plate of the amorphous alloy material is used, and continuous processing can be carried out while continuously moving it. In this case, the moving speed is set to a predetermined value, and the moving speed is The electric furnace passage time based on the following may be used as the above-mentioned holding time. Under such temperature-maintaining conditions, the amorphous magnetic alloy material, generally a thin plate, is placed in at least two external magnetic fields and each external magnetic field is applied. In this case, each external magnetic field is applied substantially linearly to the amorphous magnetic alloy material from two or more different directions. Therefore, it is sufficient that at least two external magnetic fields each have magnetic field axes that are substantially straight lines over the entire area or a predetermined portion of the amorphous magnetic alloy material, and that the respective magnetic field axes intersect at a predetermined angle. It is. However, in such cases, it is generally better to use two external magnetic fields.
This is preferable in terms of the simplicity of the device. When applying two external magnetic fields, it is preferable that the predetermined angles be approximately right angles. On the other hand, thin plates thereof are most often used as amorphous magnetic alloy materials. Therefore, when the present invention is applied to the thin plate, it is preferable that the two or more external magnetic fields each have a component within the plane of the thin plate. Therefore, when applying the present invention to a thin plate, the above-mentioned
Favorable results can be obtained if the field axes of the two or more external magnetic fields are approximately parallel to the thin plate surface and symmetrical, for example, when two external magnetic fields are used, they are approximately perpendicular to each other. . In such cases, any known electromagnet, Helmholtz coil, solenoid coil, or other coil may be used as the external magnetic field source, and in some cases, one external magnetic field source may be a permanent magnet. These may be used appropriately depending on the processing mode. For example, as shown in FIG. 1, a magnetic field parallel to the plane of the thin plate 10 and perpendicular to each other
Two pairs of electromagnets 211, 21 that generate H ₁ and H ₂
As _shown in FIG _. ,25
2 and a solenoid coil 26. In addition, in the area where two or more external magnetic fields are linearly applied, a thin plate 10 having a predetermined shape may be fixedly arranged as shown in FIG. Alternatively, an electric furnace 4 may be provided within the area, and the continuous thin plate 15 may continuously pass through the electric furnace 4. In this way, when applying the above two external magnetic fields, the direction of the composite magnetic field of these two external magnetic fields is rotated, and the magnetic anisotropy in the material induced by this composite magnetic field is made isotropic. . In this case, as long as the direction of this composite magnetic field is rotated, the induced magnetic anisotropy induced within the material will become isotropic, and the desired effect of the present invention will be achieved. However, in order to make the anisotropy more isotropic and further improve the magnetic properties, it is preferable to rotate the induced magnetic anisotropy axis induced by the synthetic magnetic field at least once. Just rotate it 180 degrees. At this time, it is preferable that the combined magnetic field rotates at a substantially constant speed, but the rotation may be continuous or intermittent. Further, at this time, forward and reverse rotations may be repeated alternately. Furthermore, the rotation speed is
There is no particular restriction as long as the rotation speed is not extremely high and as long as the desired rotation is performed within the heating holding time, but in general, it may be carried out at about 10 to 10 ⁵ ppm. As described above, there are various ways of rotating the synthetic magnetic field, but among these, the synthetic magnetic field rotates approximately within the above heating holding time.
Preferably, the rotation is performed by an angle of 180° or more in one direction, or such rotation is repeated alternately in the forward direction and then in the forward direction. To rotate the composite magnetic field in this way, it is sufficient to change at least one of the two or more external magnetic fields, usually preferably two or more. That is, in a preferred embodiment, there are two external magnetic fields, and the field strength of at least one of the two external magnetic fields may be changed in one direction or in the positive and negative directions. In this case, at least one of the external magnetic fields may be changed at a speed corresponding to the rotational speed of the above-mentioned combined magnetic field. Further, when the intensity of both external magnetic fields is changed, the rotational speeds of both may be the same or different. However, it is preferable to change the intensity of at least one of the external magnetic fields and thereby rotate the combined magnetic field of both in the following manner. When the composite magnetic field is rotated by at least 180° as described below, the induced magnetic anisotropy not only becomes macroscopically isotropic, but also microscopically isotropic within a magnetic domain of about 100μ. This is because improvements in magnetic permeability and magnetic loss are observed that exceed what would be expected if the material were made macroscopically isotropic. First, in the case of using two external magnetic fields and rotating their composite magnetic field continuously, as mentioned above, one external magnetic field _H1 and the other external magnetic field _H2 are orthogonal to each other, and As shown in FIG. 3a, it is preferable to change both of them as alternating sine waves, to match their frequencies, and to change their phases by ±π/2. When such a configuration is adopted, the composite magnetic field rotates continuously by 180 degrees or more in a fixed direction. On the other hand, even when rotating the composite magnetic field continuously, it is also possible to perform periodic forward and reverse rotations, in which case Fig. 3b
As shown in or easily inferred from it, the alternating sine waves H ₁ , which have the same frequency and differ in phase by ±π/2 in FIG.
It is preferable to invert one of H ₂ in units of a half cycle or an integral multiple thereof. On the other hand, when two external magnetic fields are used and their combined magnetic field is rotated intermittently, H ₁ and H ₂ may be generated in a pulsed manner. In this case, with equal pulse width
H ₁ and H ₂ are generated synchronously at equal intervals, and the pulse heights of both are the same as H 1 and H ₂ as above.
It is also possible to create a sine wave with H ₂ as an envelope and rotate the composite magnetic field intermittently, but as shown in Figure 3c and d, H ₁ and H with equal pulse widths may be used. ₂ are generated alternately at equal intervals, and at that time, at least one of H ₁ and H ₂ is generated alternately positive and negative, so that the composite magnetic field becomes H ₁ or H ₂ itself, and as a result, the composite magnetic field may be rotated intermittently. In such a case, the strength of these external magnetic fields is 1
The maximum value may be changed to ~100 Oe or more. After applying the magnetic field as described above in such a heated state, the material is cooled. This cooling may be performed after stopping the application of the magnetic field, or may be performed in the magnetic field described above. Although the cooling rate can be changed variously, slow cooling is preferably used. The magnetic field heat treatment as detailed above may be performed in vacuum, in an inert gas, or even in air. A preferred example of the apparatus used in the heat treatment method of the present invention, which has been described in detail above, is shown in FIG. In FIG. 1, an amorphous magnetic alloy thin plate 10 (in this case, ring-shaped) has two pairs of electromagnets 2.
It is arranged between 11, 212; 221, 222.
In this case, the electromagnets 211 and 212 are supplied with an AC power source E.
_A sinusoidal current i ₁ can be passed from
is applied so that On the other hand, electromagnet 2
21 and 222 are connected to an AC power source E via a phase controller P.
This makes it possible to conduct a sinusoidal current i ₂ having a phase different from that of i ₁ by π/2, and when this i ₂ is energized, it is perpendicular to H ₁ and parallel to the thin plate surface in Fig. 3a. A magnetic field H ₂ as shown is applied. Furthermore, the thin plate 10 is placed in the electric furnace 4. In such a configuration, when the electric furnace 4 is energized, the thin plate 10 is heated and held at a predetermined temperature, and the power source E is turned on, the temperature changes as shown in FIG. 3a.
H ₁ and H ₂ are generated, and the combined magnetic field of H ₁ and H ₂ rotates in a constant direction and at a constant period within the plane of the thin plate 10. After a certain period of time, if the electric furnace 4 is turned off and cooled, the magnetic anisotropy induced in the thin plate 10 becomes locally isotropic, and the magnetic properties are improved. In addition,
In FIG. 1, if the thin plate 10 is replaced with a continuous thin plate, the flat surface of the thin plate is placed in the direction of the plane of the drawing, and the same process as described above is carried out while continuously moving the thin plate in the direction of the arrow a, a continuous thin plate can be obtained. Heat treatment will be performed. FIG. 2 shows another example of this continuous processing. In this case, the two pairs of electromagnets 211, 212; 221, ₂₂₂ in FIG. The latter applies a magnetic field H ₁ in the in-plane width direction of the continuous thin plate 15 to move the thin plate 15 continuously in the direction of arrow b. In the present invention, by continuously moving the continuous thin plate in the magnetic fields H ₁ and H ₂ as described above, it is possible to improve the workability and greatly increase the heat treatment capacity. In addition, instead of the two pairs of electromagnets in Figure 1, for example, three coils may be arranged on the same circumferential surface at an angle of 120 degrees from each other, and the composite magnetic field of the three magnetic fields generated from the three coils may be rotated. You can also do this. Amorphous magnetic alloy thin plate subjected to heat treatment of the present invention,
Materials such as thin wires exhibit extremely excellent properties when used as they are or after being processed in a certain way for magnetic heads, various magnetic cores, and other uses. EXAMPLES The present invention will be described in more detail below with reference to Examples. Example 1 According to a known high-speed quenching method, at a cooling rate of about 10 ⁶ °C/sec, a material having a composition of (Fe ₀ . ₈₅ Co ₀ . ₁₅ ) ₈₀ B ₂₀ ,
An amorphous magnetic alloy thin plate with a thickness of 30 μm, a width of 5 cm, and a length of 100 m was prepared. A ring with an inner diameter of 6 mmφ and an outer diameter of 10 mmφ was obtained by etching this thin plate, and the first
The heat treatment of the present invention was performed using the apparatus shown in the figure. That is, the entire device is placed under a vacuum of 10 ^-1 Torr, an alternating current i ₁ is applied to the electromagnets 211 and 212 from a power source E, and a sinusoidal magnetic field H with a maximum value of 3000 Oe varying at 30 rpm is generated as shown in Figure 3a. ₁ , and an alternating current i ₂ is applied to the electromagnets 221 and 222 from the power source E through the phase controller P, which is orthogonal to H ₁ and has a π/2 phase difference from it, as shown in Figure 3a. to
Generate a sinusoidal magnetic field H ₂ varying at 30 rpm, H ₁
The combined magnetic field of H 2 and H ₂ was made to rotate at 30 rpm. At the same time, the electric furnace 4 is energized, and the ring-shaped thin plate 10
was heated and maintained at 350°C. After maintaining the heating for 20 minutes, only the electricity to the electric furnace was turned off, and slow cooling was performed in a rotating synthetic magnetic field. Next, 30 rings treated in this way were laminated with interlayer insulation (sample 1), and the coercive force was
Hc, residual magnetic flux density Br, and magnetic loss were measured. The results are shown in Table 1. Separately, for comparison, Sample 2 was obtained by laminating the above-mentioned rings in the same manner as Sample 1 without any treatment. Further, the rings were heated and held in a vacuum at 350° C. for 20 minutes without applying a magnetic field, then rapidly cooled in water, and then laminated in the same manner as Sample 1 to obtain Sample 3. Further, after winding a coil around the ring, the coil was energized in a vacuum, and while a static magnetic field of 300 Oe was applied in the direction of the ring surface, the coil was heated and held at 350° C. for 20 minutes, and then slowly cooled. The ring after this treatment is the sample 1.
Sample 4 was obtained by laminating the same layers. For samples 2 to 4 obtained in this way, sample 1
Each magnetic property was measured in the same manner. The results are also listed in Table 1.

[Table] Note that instead of removing the ring from the thin plate and heat-treating it as in Sample 1, the continuous thin plate obtained as described above is placed in the direction indicated by the arrow in Figure 1, with the plane of the thin plate positioned on the plane of the paper in Figure 1. Continuous processing was carried out while moving continuously in the a direction at a speed of 5 cm/min. Thereafter, rings were obtained from the thus processed continuous thin plate, and the magnetic properties were measured in the same manner as described above. Almost similar values were obtained. From the above results, it can be seen that according to the present invention, significantly improved and preferable magnetic properties of the transformer material can be obtained. Continuous processing is also possible,
It is also possible to process a large amount at once. Example 2 A thin plate of an amorphous magnetic alloy having a composition of Fe ₆ Co ₇₄ B ₂₀ was prepared to have approximately the same dimensions as in Example 1. This continuous thin plate was subjected to the treatment of the present invention using the apparatus shown in FIG. That is, the entire device is placed under a vacuum of 10 ^-1 Torr, and the Helmholtz coils 251 and 252 and the solenoid coil 26 are orthogonal to each other, each changing at 50 Hz as shown in Figure 3a, and furthermore, they are in phase with each other by π/2. Magnetic fields H ₁ and H ₂ with different maximum values of 500 Oe were generated. On the other hand, the continuous thin plate 15 is continuously 1 cm/cm in the direction of arrow b in FIG.
The electric furnace 4 moves the
The temperature was maintained at 300° C., and the time the thin plate 15 passed through the furnace was 30 minutes. After continuous treatment in this manner, rings were extracted from the thin plates as in Example 1, and the rings were stacked (Sample 5) to measure Hc, Br, and magnetic permeability μ ₁ at 1kHz and 1mOe. , the results shown in Table 2 were obtained. In addition, Table 2 shows one in which the above thin plate was cut out into a ring shape without any treatment and then laminated (sample 6), and one in which the thin plate was cut out into a ring shape and then a coil was wound around the ring. After applying a static magnetic field of 500 Oe in the circumferential direction of the ring and heat treating it at 300°C for 30 minutes, the magnetic properties of each of these rings stacked (Sample 7) are also listed.

[Table] From the results in Table 2, it can be seen that when the present invention is applied to magnetic head materials, the dynamic characteristics of magnetic permeability are significantly improved, and moreover, large-scale processing can be performed.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams showing one example of the apparatus used in the present invention, and FIG. 3a
- d are diagrams showing different examples of the time change t of the magnetic field strength H of the external magnetic fields (H ₁ and H ₂ ) applied to the amorphous magnetic alloy material in the present invention, respectively. 10,15...Amorphous magnetic alloy material, 211,2
12,221,222...Electromagnet, 251,252
...Helmholtz coil, 26...Solenoid coil, 4...Electric furnace.

Claims (1)

[Claims] 1 When heat treating amorphous magnetic alloy material,
At least two external magnetic fields are applied to the material while the material is heated and maintained at a temperature below the Curie point of the amorphous magnetic alloy and below its crystallization temperature.
The magnetic field is applied almost linearly from the above direction, and at this time, the direction of the composite magnetic field of the plurality of external magnetic fields is rotated so that the magnetic anisotropy induced by the composite magnetic field in the material is isotropic, and then cooled. A method for heat treating an amorphous magnetic alloy material, characterized by: