JPS59177353A - Heat treatment of amorphous magnetic alloy - Google Patents

Abstract

PURPOSE:To prevent the deterioration of the magnetic characteristics of an amorphous magnetic alloy due to crystallization such as the reduction of the magnetic permeability or the increase of the coercive force by heat-treating the alloy at the crystallization temp. or above in a magnetic field to cause partial crystallization. CONSTITUTION:An amorphous magnetic alloy of one or more among Fe, Co and Ni is heat-treated at the crystallization temp. or above in a magnetic field. The strength of the magnetic field applied is required to be higher than the coercive force of the alloy, and the strength is preferably increased to such a degree that the saturation magnetization of the alloy is obtd. The alloy is partially crystallized by the heat treatment, and the deterioration of the magnetic characteristics due to crystallization such as the reduction of the magnetic permeability or the increase of the coercive force is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a heat treatment and heat processing method for an amorphous magnetic alloy.

[Prior art and its problems]

Conventionally, good soft magnetic properties of amorphous magnetic alloys have been obtained by heat treatment or heat processing that does not cause crystallization of the alloy. However, when an amorphous magnetic alloy is applied as an all-magnetic material, heating processing at a temperature near or above the crystallization temperature may be required during the manufacture of parts. It is known that such processing causes precipitation of crystalline phases in amorphous magnetic alloys, significantly reducing their magnetic properties. In order to avoid crystallization during such heat processing, methods such as increasing the crystallization temperature of amorphous magnetic alloys have been taken. At present, it is difficult to develop metal alloys.

In view of the above circumstances, the present inventor has conducted various studies in order to reduce the deterioration of magnetic properties due to crystallization during heat treatment and processing at temperatures near and above the crystallization temperature, and as a result, the present invention has been completed. That's all.

[Purpose of the invention]

An object of the present invention is to avoid or reduce deterioration of magnetic properties due to crystallization when the ambient temperature rises above the crystallization temperature of the alloy in heat treatment and heat processing of an amorphous magnetic alloy.

[Summary of the invention]

In order to achieve the above object, the present invention applies a magnetic field greater than the coercive force of the alloy when heat treating the amorphous magnetic alloy at a temperature higher than the crystallization temperature of the alloy or processing that involves heating. be. The applied magnetic field needs to be greater than or equal to the coercive force of the alloy, but in terms of the actual q, the p
~ A magnetic field greater than that at which sum magnetization can be obtained is desirable 1. A magnetic field less than the coercive force is not effective in improving the magnetic 41C properties.

The direction of the applied magnetic field to the amorphous magnetic alloy, is it a DC magnetic field or an AC magnetic field? , or a rotating magnetic field can be selected arbitrarily depending on the intended use of the alloy.

〔Effect of the invention〕

In the present invention, the crystallization temperature Ifj of the amorphous magnetic alloy:
By heat treatment and heat processing at J SO soil σ) temperature, reduction in magnetic permeability due to crystallization and increase in coercive force are effectively avoided and reduced. It is something.

[Invention';! -7 Example] Example XV of the present invention is O(Co 019o
Fe l), 06Cr6. . 4) 7ys! 1o
An alloy with a composition of B+3 (atomic %) was processed by the single roll method i
A thin amorphous alloy with an average thickness of 30 μm was rapidly cooled. 7'l: Formed. The crystallization temperature Tcry of the amorphous alloy was 490°C, and the Curie salt JiTc was 400°C. The same thin strip was punched into a ring shape with 10 outer diameters and 6 inner diameters and used as a sample. 10K perpendicular to this ring surface
2 at a temperature of 520°C above the crystallization temperature by applying a magnetic field of e.
Heat treatment was performed for 0 minutes.

Further, as a comparative example, a similar sample was subjected to the same heat treatment in the absence of a magnetic field.

The progress of crystallization of both is Dowa IW-tX#i!
This was confirmed by diffraction and electron microscopy observations.

Their effective magnetic permeability was measured using an HP impedance meter, and the frequency characteristics are shown in FIG. As shown in FIG. 1, heat treatment in a magnetic field did not show significantly higher magnetic permeability over a wide frequency range than in the absence of a magnetic field.

In addition, the amorphous magnetic alloy that can be used in the present invention and 1
-2) It is effective for any amorphous metal whose main component is one or more of Fe, Co, and Ni.

[Brief explanation of drawings]

FIG. 1 is a frequency characteristic diagram of effective magnetic permeability of Examples and Comparative Examples according to the present invention. In the figure, 1 shows the characteristics of the example, and 2 shows the characteristics of the comparative example.

Claims (1)

[Claims] (1) Is it possible to partially crystallize an amorphous magnetic alloy by heat treating it in a magnetic field at a temperature higher than the crystallization temperature of the alloy? A heat treatment method for amorphous alloys.