JPS596360A - Heat treatment of amorphous magnetic alloy - Google Patents

Abstract

PURPOSE:To carry out the heat treatment of a large amount of or/and a continuous amorphous magnetic alloy, by a method wherein an amorphous magnetic alloy thin strip is applied with a magnetic field sufficient for being equalized in induction magnetic anisotropy in two directions crossing at right angles in the main surface of said thin strip at the Curie temp. thereof or less and the crystallization temp. thereof or less to be subjected to heat treatment. CONSTITUTION:An amorphous magnetic alloy thin strip 1 is wound cylindrically and, for example, a solenoid coil 2 is provided to the cylindrical thin strip 1 to apply a magnetic field H1 thereto in the longitudinal direction thereof at the Curie temp. of said alloy or less and the crystallization temp. thereof or less to carry out heat treatment. By this method, induction magnetic anisotropy K//l is generated in the longitudinal direction within the main surface of the thin strip 1. In the next step, an external magnetic field H3 is applied to the same cylindrical thin strip in the width direction thereof under the same temp. condition as mensioned above to carry out heat treatment. In this case, induction magnetic anisotopy Krt. anglel is generated in the direction crossing the longitudinal direction at right angles within the main surface of the thin strip 1 to complete heat treatment in a time satisfying the condition of K//lapprox.=Krt. anglel. By this method, an amorphous magnetic alloy having high permeability capable of being used as a soft magnetic material can be prepared by a mass production system.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for heat treatment of an amorphous magnetic alloy, and particularly to a method for heat treatment of an amorphous magnetic alloy, which can easily produce an amorphous magnetic alloy having a high magnetic permeability in large quantities and/or continuously. The present invention relates to a method for heat treatment of magnetic alloys.

Amorphous magnetic materials manufactured by ultra-quenching, sputtering, and plating methods usually have low magnetic permeability (μ') in the as-manufactured state, so they cannot be used directly as soft magnetic materials. It is. What determines the magnetic permeability of an amorphous magnetic material in the composition of a magnetostrictive material is anisotropy induced during manufacturing, that is, induced magnetic anisotropy. Based on the fact that this induced magnetic anisotropy can be freely controlled by heat treatment in a magnetic field, the present inventors previously calculated Kix : Kiy (Kfx
We proposed that when heat treatment is performed in a magnetic field that satisfies the following conditions: induced magnetic anisotropy in the x direction, Ki7: induced magnetic anisotropy in the y direction, a significant improvement in magnetic permeability can be obtained. However, although this proposal by the present inventors has presented the principle, it is difficult to process in large quantities and/or continuously in practice.

The present invention was made in view of these five circumstances, and provides an amorphous magnetic alloy that satisfies the isotropic condition of induced magnetic anisotropy and that can be heat-treated in large quantities and/or continuously. A heat treatment method is provided.

In the present invention, an induced magnetic change is applied to an amorphous magnetic alloy ribbon in a first direction in the principal plane of the amorphous magnetic alloy ribbon at a temperature below the Curie temperature and below the crystallization temperature of the alloy. Heat treatment is performed by applying a magnetic field sufficient to generate orientation, and the amorphous magnetic alloy ribbon is perpendicular to the first direction in the main plane at a temperature below the Curie temperature and below the crystallization temperature of the alloy. A second direction VC.

The heat treatment is performed by applying a magnetic field sufficient to make the induced magnetic anisotropy in the first direction equal to the induced magnetic anisotropy in the second direction. Thereby, the isotropic condition of induced magnetic anisotropy can be satisfied, and the amorphous magnetic alloy can be heat-treated in large quantities and/or continuously.

Hereinafter, an example of the heat treatment method for an amorphous magnetic alloy according to the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of the invention. In this example, an amorphous magnetic alloy ribbon (1) is wound into a cylindrical shape, and a solenoid coil (2), for example, is applied to this to form a cylindrical shape at a temperature below the Curie temperature and below the crystallization temperature of the alloy. Heat treatment is performed by applying a magnetic field H1 in the circumferential direction, that is, in the longitudinal direction of the ribbon (1), to generate induced magnetic anisotropy Kl/Q in the longitudinal direction within the main surface of the ribbon (1). Next, the ribbon (1) in the same previous state is heat-treated by applying an external magnetic field H2 in the width direction of the ribbon (1) at a temperature below the Curie temperature and below the crystallization temperature of this alloy. Induced magnetic anisotropy KLQ is generated in the width direction perpendicular to the longitudinal direction within the principal plane of (1), and Kttg = Klg
Finish the heat treatment in a time that satisfies the following conditions. That is, in this case, when applying the magnetic field H2, the result generated by the magnetic field H1 //
As l decreases, Kl, which is orthogonal to it, increases, so KnQ
The heat treatment is finished at the time when = Klg.

According to this method, it is possible to heat treat a large amount of amorphous magnetic alloy. This method is particularly suitable for transformer cores. In this method, the amorphous magnetic alloy ribbon (1) is subjected to heat treatment in a magnetic field while being wound into a cylindrical shape, so the amorphous magnetic alloy ribbon (1) tends to warp after the heat treatment.

FIG. 2 is another example of the present invention. In this example, an amorphous magnetic alloy ribbon (1) is transferred in the form of a flat plate to one side, and at a first position during the transfer, for example, a solenoid coil (2) is used to cool the alloy to below the Curie temperature. Heat treatment is performed by applying a magnetic field H1 in the longitudinal direction of the ribbon (1) at a temperature below the crystallization temperature to generate induced magnetic anisotropy //Q in the satin direction within the main surface of the ribbon (1). . Then, at a second location during the transfer, similarly at a temperature below the Curie temperature and below the crystallization temperature of the alloy.

The ribbon (1) is heat-treated by applying an external magnetic field H2 in the width direction to generate an induced magnetic anisotropy of 1 g in the width direction perpendicular to the longitudinal direction within the main surface of the ribbon (1), and Ktti = The heat treatment is completed in a time that satisfies the conditions of K days.

According to this method, since the amorphous magnetic alloy ribbon (1) is heat-treated in a flat plate state in a magnetic field, it is possible to prevent the ribbon (1) from warping after the heat treatment, and to continuously form amorphous alloys in large quantities. Enables heat treatment of magnetic alloys. Therefore, since the amorphous magnetic alloy ribbon heat-treated by this method is obtained in a flat plate shape without warping, it has good workability in subsequent punching, etching, etc.
For example, it is suitable for soft magnetic core materials such as magnetic heads.

Note that the order in which the magnetic fields H1 and H2 are applied in FIGS. 1 and 2 does not matter. That is, in the above example, the magnetic field H1 was applied first and the magnetic field H2 was applied later, but the opposite magnetic field H2 may be applied first to the magnetic fields H, x, and u. In any order, Kttg' in Hl, H2 magnetic field heat treatment
The present invention is achieved by satisfying the conditions of Kig. Therefore, there is essentially no difference between alternating current and direct current in magnetic fields.

In addition, in the above example, magnetic fields H1 and H2 were applied on the main surface of the ribbon (1) in the width direction perpendicular to the longitudinal direction, respectively, but the magnetic fields H1 and H2 were applied in the width direction perpendicular to the longitudinal direction of the ribbon (1), respectively, but the magnetic fields H1 and H2 were applied in the width direction perpendicular to the longitudinal direction of the ribbon (1). The magnetic fields H1 and H2 may be applied in the directions.

Further, in both FIGS. 1 and 2, heat treatment is performed in a furnace.

Furthermore, although not shown in FIG. 2, for example, in the example of FIG.
An external magnetic field H3 is applied perpendicularly to the plate surface of the alloy at a temperature below the Curie temperature and below the crystallization temperature.
It is also possible to make the induced magnetic anisotropy substantially equal three-dimensionally by heat treatment. In this case, further improvement in magnetic permeability in the high frequency region can be expected.

Next, examples of the present invention will be described.

Example (1) The sample was Fe5Co75Si4B16 (crystallization temperature 42
0'C, - + lily temperature 570℃) thickness approximately 20μm,
An amorphous magnetic alloy ribbon with a length of about iom was used, wound into a cylindrical shape, and heat-treated using the heat treatment method shown in Fig. 1. Initially, the temperature Ta = 360 °C, the time fa = 30 m1n,
Induced magnetic anisotropy was given with a magnetic field H2==2.4 KOe. After that, heat treatment temperature Ta = 300'C1 hour ta
The heat treatment was performed under the conditions of = 10 m1n and magnetic field H1 = 300e. Table 1 shows the results. The magnetic field for measuring magnetic permeability is 10 m0e.

Table 1 Example (2) Using the same sample as in Example (1), heat treatment was performed at the first position using the heat treatment method shown in Figure 2 (the order of applying the magnetic field was reversed) at Ta = 360°C and time ta. =3Qmln
Induced magnetic anisotropy was given in the S magnetic field H2-2,4KOe, and heat treatment was performed at the primary position at temperature Ta = 300°C and time ta =
10m1n.

Heat treatment was performed under the condition of magnetic field H1-300e. The results were the same as in Table 1 above.

As described above, according to the present invention, the isotropic condition of induced magnetic anisotropy is satisfied for an amorphous magnetic alloy.

Moreover, it enables large-scale and/or continuous heat treatment, thus making it possible to mass-produce amorphous magnetic alloys with high magnetic permeability that can be used as soft magnetic materials.

[Brief explanation of drawings]

FIGS. 1 and 2 are schematic diagrams showing examples of heat treatment steps in the present invention, respectively. (1) is an amorphous magnetic alloy ribbon, (2) is a solenoid coil, and (Hl) (H2) is an applied magnetic field. Continued from page 1 0 Inventor Kazuhiko Hayashi Sony Corporation Central Research Laboratory, 174 Fujitsuka-cho, Hodogaya-ku, Yokohama City

Claims (1)

[Claims] A magnetic field sufficient to generate induced magnetic anisotropy in a first direction in the principal plane of the amorphous magnetic alloy ribbon at a temperature below the Curie temperature and below the crystallization temperature of the alloy. is applied in a second direction perpendicular to the first direction within the main surface of the ribbon at a temperature below the Curie temperature and below the crystallization temperature of the alloy. 1. A method for heat treatment of an amorphous magnetic alloy, comprising applying a magnetic field sufficient to make the induced magnetic anisotropy in the second direction equal to the induced magnetic anisotropy in the second direction.