JPS61266545A - Amorphous magnetic alloy - Google Patents

Abstract

PURPOSE:To improve the wear and corrosion resistances and workability by adding a prescribed percentage of a finely powdered filler having a prescribed particle size to Fe, Co, Ni, B, Si, etc. CONSTITUTION:This amorphous magnetic alloy contains 0.5-25wt% finely powdered filler of alumina, titanium oxide, calcium carbonate or the like having 0.05-1.5mum average particle size. The alloy has a composition contg. one or more among Fe, Co and Ni and one or more among B, Si, C, P and Zr.

Description

[Detailed description of the invention] Background of the invention Technical field The present invention relates to an amorphous magnetic alloy.

Prior art and its problems Amorphous magnetic alloys have been widely used due to their excellent soft magnetic properties.
In particular, it has attracted attention as a material for magnetic heads, and is being put into practical use.

The composition of such an amorphous magnetic alloy for a magnetic head includes Si, B, etc. as vitrifying elements, and further contains Cr, Mo, and W as necessary.

Tj, Zr, Hf, V, Nb, Ta, Ru.

It is preferable to use one or more of elements such as Rh, -Pb, Os, Ir, and Pt, and one or more of Fe, Co, and Ni to form magnetostrictive O.

In particular, an amorphous magnetic alloy containing a predetermined amount of Ru has a high saturation magnetic flux density, an extremely good surface quality, and furthermore, an extremely good punchability with very little burr. Moreover, when used in a core for a magnetic head, it has excellent wear resistance, and the amount of wear is extremely small even when a magnetic recording medium is run at high speed. Furthermore, it has excellent eating habits, has significantly less wear due to chemical factors, and its magnetic properties hardly change over time even when stored under poor conditions.

However, Ru, which is extremely useful in improving the properties of amorphous magnetic alloys, is expensive because it is a noble metal, and there are concerns about its stable supply.

■ Purpose of the Invention The purpose of the present invention is to provide a lower-cost amorphous magnetic alloy with excellent properties in place of Ru-containing amorphous magnetic alloys that are expensive and have uncertain supply. be.

■Disclosure of invention Such objects are achieved by the invention described below.

That is, the present invention is an amorphous magnetic alloy characterized by containing a fine powder filler.

■Specific structure of the invention Hereinafter, a specific configuration of the present invention will be explained in detail.

The fine powder filler used in the present invention is preferably a chemically stable and wear-resistant fine powder of alumina, titanium oxide, calcium carbonate, barium sulfate, or the like.

Further, the content of these fine powder fillers in the amorphous magnetic alloy is preferably about 0.5 to 25 wt%.

If the content of the fine powder filler is less than 0.5 wt%, for example, even if alumina, which has relatively good wear resistance, is used, the head wear amount when used as a video head is 10 g/1.
It will be 00 hours.

Moreover, when it exceeds 25 wt%, the saturation magnetic flux density of the magnetic properties becomes 500 Gauss or less, and the coercive force also exceeds 0.10e, which is not desirable for a magnetic head.

Furthermore, the average particle size of these fine powder fillers is 0,0
5 to 1.5 JJ, preferably about 11.

If the average particle size is less than 0.05 μm, the present invention will not be effective, while if it exceeds 1.51 Lm, the surface properties will deteriorate.

The composition of an amorphous magnetic alloy to which such a fine powder filler is dispersed and added is Fe 2 or Co 2 .

Contains one or more types of Ni, Si as a vitrification element,
It may be of various compositions containing 10 to 30 wt% of one or more of B, P, C, Zr, etc., and further containing other metals as required.

In particular, among these, 10 to 3 as vitrifying elements
Preferably, the material contains 0 wt% of St and/or B, and one or more of Fe, Co, and Nf so that the magnetostriction is zero.

Also, these include Cr, Mo, W, and Ti.

Zr, Hf, V, Nb, Ta, Rh, Pb.

One or more elements such as Os, Ir, and Pt may be contained in an amount of about 15 wt% or less.

The amorphous magnetic alloy containing the above-mentioned fine powder filler is
It is in an amorphous state with virtually no long-range regularity.

Further, the thickness is about 10 to 20 JLrm.

Such an amorphous magnetic alloy containing dispersed fine powder filler is usually manufactured as follows.

That is, by adding fine powder filler to the molten master alloy,
This is rapidly cooled at a cooling rate of about 106° C. 7 seconds and solidified to obtain an amorphous magnetic alloy. To rapidly cool the molten metal of the master alloy, the molten metal is injected from a nozzle, and various known methods such as the twin roll method, single roll method, and centrifugal quenching method are used.
In particular, it may be rapidly cooled according to the single roll method.

In addition, since the dispersion also has a large difference in specific gravity, it is preferable to stir it in the molten metal in a high frequency induction furnace.

Such amorphous magnetic alloys have extremely excellent wear resistance, corrosion resistance, and magnetic properties, and are extremely useful in applications such as cores for magnetic heads.

■Specific effects of the invention The amorphous magnetic alloy according to the invention exhibits the following effects.

(1) It has high wear resistance, and therefore, even when configured as various magnetic heads, the amount of wear under high-speed contact running is extremely small.

(2) It has excellent properties such as high corrosion resistance, little chemical wear caused by running media in contact with it, and very little decrease in high-frequency input/output level even when stored under poor conditions. have.

(3) It has good suitability for processing such as punching, and even when used as a core for a magnetic head, the yield is high, and there is no decrease in space factor due to pars or decrease in recording/reproducing output.

(4) Compared to conventional amorphous magnetic alloys containing Ru, it does not use expensive Ru and uses fine powder filler, which is inexpensive and stable in terms of supply, resulting in reduced manufacturing costs and stability. This will result in the establishment of a reliable manufacturing system.

The inventor conducted various experiments to confirm the effects of the present invention. An example is shown below.

EXPERIMENTAL EXAMPLE An amorphous magnetic alloy A having a composition of (Fe5.5''94.5) 70Ru4''4 (Si10 days 90) 22 and having a width of 15 mm and a thickness of 50 μm was obtained.

In addition, A! with an average particle size of 0.3 grm is added to the molten metal! L203
Fine powder was added to contain 8wL% of fine powder filler (F
e5.5"134.5) 72Cr4 (S'10"90)
24 amorphous magnetic alloys B of the same size were obtained.

The Bs of these samples A and H are shown in Table 1.

After this, from samples A and B, using a cemented carbide mold,
Half core shape for video head.

I did some punching. In this case, one half of the core had a 0-shape and the other had a C-shape that could be wound.

Table 1 shows the measurement results of the shear plane of Paris when 100,000 core chips were punched.

Next, a video head was manufactured using the core chips obtained from these samples A and B.

Using this video oven, store it at 25℃ and relative humidity 5.
The videotape was run for 100 hours at 0%.

Table 1 shows the results of measuring the depth of wear on the front surface of the head after running using a surface roughness meter.

Separately, audio heads were manufactured using each sample.

That is, each sample was molded using a cemented carbide mold, and
Punched out in a letter shape. Next, a plurality of core chips of each type were stacked to a thickness of 0.6 mm to obtain a half-core core. An audio magnetic head was fabricated using this half core.

For each audio head obtained in this way, γ−
The amount of chemical wear was measured under high temperature and high humidity using a tape using Fe2O3 as a magnetic powder and vinyl chloride acetate as a binder.

That is, this tape was heated at 40°C and 95% relative humidity.
The wear depth of the head after running for ooo hours was measured using a surface roughness meter.

The results are shown in Table 1.

Table 1 A 8.010.50.2 From the results shown in Table 1, the effects of the present invention are clear.

Procedure Neho Seisho (self-motivated) 6 August 29, 1985

Claims (4)

[Claims] (1) An amorphous magnetic alloy characterized by containing a fine powder filler. (2) The amorphous magnetic alloy according to claim 1, wherein the content of the fine powder filler is 0.5 to 25 wt%. (3) The average particle size of the fine powder filler is 0.05 to 1.5μ
The amorphous magnetic alloy according to claim 1 or 2, which is m. (4) One or more of Fe, Co and Ni, B, Si,
The amorphous magnetic alloy according to any one of claims 1 to 3, having a composition containing one or more of C, P, and Zr.