JPS6274052A - Fe-co soft magnetic material - Google Patents

Abstract

PURPOSE:To carry out foil formation without deteriorating saturation magnetic flux density by forming an Fe-Co alloy with a specific composition into foil by a melt-rapid-cooling method. CONSTITUTION:The Fe-Co alloy consisting of, by weight, 35-50% Co and the balance essentially Fe is melted and this molten alloy is rapid-cooled by a single-roll method, etc., to be formed into foil. In the above alloy composition, one or more elements among Si, Al, Cr, V, Nb, Ti, Mo and W are incorporated by <=10% in total, if necessary. In this way, a soft magnetic material capable of forming into sheet-like state without causing practical deterioration in saturation magnetic flux density and having improved characteristics such as electrical resistivity, etc., can be provided. This magnetic material can be used in various fields such as magnetic heads, iron cores for small-sized relay, diaphragms, for telephone set, etc.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to soft magnetic materials, more specifically Fe-C
The present invention relates to a Fe--Co based soft magnetic material that can be used in the form of a thin plate. (Prior Art and Problems) There are various soft magnetic materials, and they are used for different purposes depending on their magnetic properties. In general, the magnetic properties required for a soft magnetic material vary depending on the parts used, but include: ■ High magnetic flux density B ■ High magnetic permeability μ ■ Low coercive force He ■ Electrical resistivity A high ρ is required. Conventionally, Fe--Co alloy has been known as a promising soft magnetic material that satisfies the above requirements. As shown in Figure 1, this alloy is a material that exhibits the maximum saturation magnetic flux density (Bs) when it contains approximately 35 to 50% Co, but although it has the disadvantage of low electrical resistivity, it is particularly difficult to manufacture. There are problems, particularly in that cold workability is extremely poor, making it very difficult to form into thin sheets. Therefore, only a few of them have been put to practical use, such as relay cores and telephone diaphragms. For this reason, permendur (49%Fe-49%Co-2
%V) has been attempted. It is difficult to make this into a thin sheet, and in fact there are almost no examples of it being made into a thin strip by cold rolling. (Objective of the Invention) The object of the present invention is to eliminate the drawbacks of the conventional Fe-Co-based soft magnetic materials mentioned above, to be able to process them into a thin plate shape without substantially reducing the saturation magnetic flux density, and, if necessary, to reduce the electrical resistance. The object of the present invention is to provide a Fe-Co-based soft magnetic material that can also improve the magnetic flux rate. (Structure of the Invention) In order to achieve the above object, the Fe-Co-based soft magnetic material according to the present invention contains 35 to 50% Co, and if necessary, a relatively small amount of a specific third element is added thereto. Fe-C
O-based alloy, which is made into a thin ribbon using a method similar to the molten metal quenching method used to produce amorphous ribbons, and this molten metal quenching method refines the crystal grains and improves brittleness. A soft magnetic material made into a thin ribbon is obtained. In the present invention, Co is contained in a range of 35 to 50% which shows the maximum saturation magnetic flux density (Bs) in the Fe-Co system, but as shown in Fig. Since the e-Co alloy has a low electrical resistivity (ρ), a third element shown below can be added as necessary in order to improve the electrical resistivity without significantly lowering Bs. That is, as the third element, Si, Al1. Cr, V
, Nb, Ti, Mo, W, and Zr in a total amount of 10% or less. Adding a large amount exceeding 10% is not preferable because the Bs decreases significantly. Among these elements, V has the effect of significantly increasing ρ without lowering Bs, and also has the effect of improving brittleness, and a preferable range is 1 to 4%. Also, Si
, A Q , Cr, Nb, Ti, Mo, W and Zr
are all elements that can significantly improve ρ,
In particular, Sl, AM, and Cr have a remarkable effect of improving ρ, and Ti, Nb, and Cr are elements that can also improve corrosion resistance, so their addition is effective when used in magnetic heads and the like. The Fe--Co alloy having the above composition can be easily formed into a thin ribbon by a molten metal quenching method known as a single roll method, a twin roll method, or the like. (Example) A Fe--Co alloy having the composition shown in Table 1 was melted in a high-frequency induction furnace and sucked up into a quartz tube to be used as a base material for rapidly cooling the molten metal. Next, it is made into a thin ribbon by a single roll method in an Ar atmosphere, and the a? I was able to obtain iF. These thin strips were subjected to 900'CX in vacuum.
After being annealed for 4 hours. In addition to measuring DC magnetic properties and electrical resistivity, a corrosion resistance test (salt spray test) was also conducted, and a bending test was also conducted. The above results are shown in Table 1.

[Left below]

As shown in Table 1, all samples (thin strips) have 180
°It is bendable and has improved brittleness, and Bs
It can be seen that it is also possible to increase ρ without significantly reducing ρ. (Effects of the Invention) As explained above, according to the present invention, it is possible to provide a soft magnetic material in which a Fe-Co alloy is made into a thin ribbon.
Moreover, it is possible to improve other properties such as electrical resistivity without substantially reducing saturation magnetic flux density, so it is possible to improve other properties such as electrical resistivity without substantially reducing saturation magnetic flux density.
It becomes possible to use it in fields such as iron cores for small motors and telephone diaphragms, and it also becomes possible to miniaturize parts.

[Brief explanation of drawings]

Figure 1 shows the saturation magnetic flux density (
Bs), electrical resistivity (ρ), and Co content. Patent applicant Daido Steel Co., Ltd. Figure 1 C, gold layer t (S)

Claims (1)

[Scope of Claims] 1. An alloy containing 35 to 50% Co by weight (the same applies hereinafter) and the remainder substantially consisting of Fe, which is formed into a thin ribbon by rapid cooling from a molten metal. An Fe-Co-based soft magnetic material characterized by: 2 Contains 35-50% of Co, and further contains Si, Al, Cr
, V, Nb, Ti, Mo, W, and Zr in a total of 10% or less, and the remainder is substantially Fe.
An Fe--Co based soft magnetic material, characterized in that it is an alloy consisting of a molten metal and formed into a thin ribbon by rapid cooling from a molten metal. 3. The Fe--Co based soft magnetic material according to claim 2, wherein the alloy contains 35 to 50% Co and 1 to 4% V, with the remainder being substantially Fe.