JPS6169939A - Amorphous alloy for magnetic head - Google Patents

Abstract

PURPOSE:To obtain an amorphous alloy for a magnetic head having superior wear resistance by rapidly cooling a molten Co alloy having a specified composition so as to make the alloy amorphous. CONSTITUTION:A molten Co alloy having a composition represented by formula I or II is sprayed on a cooling body such as a single roll rotating at high speed from the nozzle of a quartz pipe under the pressure of an inert gas such as Ar. The molten alloy is rapidly cooled on the roll to form an amorphous thin film. Thus, an amorphous alloy for a magnetic head having superior wear resistance and high magnetic permeability is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an amorphous alloy for magnetic heads with improved wear resistance.

Technical background of the invention and its problems Conventionally, high magnetic permeability materials used for magnetic heads include, for example, Fe-Ni alloy (Permalloy) having a crystal structure and Fe-8i-At alloy (Sendust). However, although the Fe-Ni alloy has high magnetic permeability, it has poor wear resistance, and the Fe-8i-Al alloy has excellent wear resistance, but is brittle, so plastic working is difficult.
Two difficulties.

On the other hand, amorphous alloys that do not have a crystal structure have been found to have excellent mechanical and magnetic properties as materials for magnetic heads, and have recently attracted attention as new materials. However, although amorphous alloys generally have a Puickers hardness of as high as 1000+, it has been found that when using a magnetic head f2, the wear of the head due to the chives is large, which poses a major practical problem. was.

Various discussions have been made regarding the wear mechanism when such an amorphous alloy is used in a magnetic head, and mechanical wear and chemical factors are considered to be the main causes. However, as a result of research, no correlation was found between the Guitzkaas hardness of amorphous alloys and the amount of wear, and in the case of magnetic heads, it is recognized that C2 is largely influenced by mechanical factors. Therefore, it has been desired to develop an amorphous alloy having higher wear resistance against head wear C2 due to the chemical factor C2.

OBJECTS OF THE INVENTION The present invention has been made in view of the above points, and provides an amorphous alloy for a magnetic head that has excellent wear resistance and high magnetic permeability.

SUMMARY OF THE INVENTION The present invention provides an atomic concentration (COI -a-bFeaRub); +oioi-X-
The first gist is an amorphous alloy for magnetic heads where ySi:<By, and furthermore (Ca1-a-b-cFe aRu bTMc)ko
The second subject matter is an amorphous alloy for a magnetic head called 'sy-X-YS i XBY.

However, TM in the above formula is Ti, V, Cr, Mn, Ni, Z
r.

At least one of Nb, Mo, Hf, Ta, W, 0.02≦a≦o, os, 0.0? ≦b≦0
．． 20,0.01≦c≦0.10.0≦x≦20,4≦
y≦9.

In the alloy of the present invention, the effects of the additive elements, the composition ratio, and the reasons for their limitations will be explained below.

In C2 of the present invention, Fe (iron) has the effect of improving magnetic permeability, and is most effective when its composition ratio a is in the range of 0.02 to 0.08, and outside this range, the magnetic permeability decreases.

Ru (ruthenium) has a remarkable effect on improving the wear resistance of the alloy of the present invention, and its composition ratio is 0.07.
The range of ≦b≦0.20 is desirable. In this case, the density is 0.0
? If it is less than 0, 20, the effect of improving wear resistance will be small.
If it is added in excess of this amount, the improvement in wear resistance approaches the limit of 2, and the saturation magnetic flux density decreases to below 7500 GLJ, so it is specified in the above range. Note that Ru is an element that belongs to C2 together with Pt (platinum), Pd (radium), Rh (ronium), etc.;
etc. are not suitable because they tend to become amorphous, and R
h improves wear resistance (2) Although it has some effect, when added in a sufficient amount, a large improvement in wear resistance C; a remarkable effect can be obtained.

Si (silicon) co-promotes ζ2 amorphousization with B (ffron), which has the most effective effect, and its composition ratio X is preferably in the range O≦x≦20. In this case, even if Si is not included, the alloy of the present invention can be made amorphous if B is added, and if it exceeds 20, the saturation magnetic flux density will be 75,000 or less (AoB is not preferred because it is 2). It has the effect of promoting the amorphization of the alloy and improving the wear resistance, and its composition ratio y is preferably in the range of 4≦y≦9.In this case, if y is less than 4, the alloy becomes amorphous. Not only is it difficult to produce a high-quality alloy, but also it is difficult to obtain a high magnetic permeability, and if the value exceeds 9, the wear resistance deteriorates, so the above range was specified.

Each of the above elements is a common element in the first and second inventions. Ti, V, Cr, Mn, Ni, Zr, Nb, M
o, Hf.

At least one type of TaIW, which significantly improves the wear resistance of the present alloy through a synergistic effect with Ru, increases magnetic permeability, decreases coercive force, and improves thermal stability. etc., are two effective element groups for improving properties.

It is desirable that the composition ratio C of TM is in the range of 0.01≦c≦0.10; if it is less than 0.01, the effect of addition is small;
If it exceeds 70, the magnetic permeability decreases and the effect of improving wear resistance becomes saturated, so the above range is specified.

Embodiments of the Invention Example 1 A liquid quenching method in which a molten alloy is spouted onto the surface of a single roll rotating at high speed using argon gas pressure from a quartz tube nozzle to quench it, was used to produce 12 pans in width, 20 μm in thickness, and 1077 L in length.
An amorphous alloy ribbon sample was prepared. The alloy compositions of the samples used are listed in Table 1. Thread 6 (as shown in Figure 2).

The obtained ribbon sample was punched into a ring with an outer diameter of 10 Bφ and an inner diameter of 8 Bφ, laminated with an interlayer insulator interposed, and heat treated for 10 minutes at a temperature higher than one Curie temperature and lower than the crystallization temperature.
Ten sheets of this were laminated, and the primary and secondary coils were wound to measure the magnetic permeability and DC magnetization curve.

The magnetic permeability was measured using a Maxwell bridge up to a frequency of 100 KHz and a radio frequency bridge in the MHz band. The DC magnetization curve was measured using an automatic self-recording magnetometer.

In addition, a magnetic head was prototyped by punching out the shape of an audio magnetic rad core from an amorphous alloy ribbon sample, and its wear resistance was evaluated. To measure wear, we used a surface roughness meter to measure changes in the sliding surface of the head before and after running an audio cassette tape coated with r-Fe203 for 1,000 hours, and calculated this per 100 hours. It was calculated by converting it into

Furthermore, Gain Curse hardness was measured using a Micro Gain Curse hardness meter.

The effective magnetic permeability at 1 KHz obtained in this way (
The properties such as μ'IK), coercive force, saturation magnetization, amount of wear, and gain-curse hardness are shown in Table 1.

Comparative Example 1 The composition of the amorphous alloy was as shown in the ¥1 table (2Ru
The amount added is less than the range specified in the present invention (boiled 7
), those in which the amount of Ru added is greater than the range specified in the present invention (A8), and those in which Rh is added instead of Ru (A8)
A5), and one containing no Ru at all (& /-Q
, & 11), samples were prepared in the same manner as in Example 1 above.

Various properties of these samples were also investigated, and the results were presented in the first
Also listed in the table.

As is clear from the results in the table above, the amorphous alloy of the present invention has R
It was confirmed that the addition of u significantly improved wear resistance and excellent magnetic properties. This (two versus Rh
The effect of improving wear resistance (2) is insufficient with the addition of .

Example 2 Samples were prepared in the same manner as in Example 1 for amorphous alloys whose alloy compositions are shown in Table 2, 5 to 17 I, and the effective magnetic permeability, coercive force, saturation magnetic flux density, wear amount, and The Putzkaas hardness was measured. The results are shown in Table 2.

Those whose added amount is greater than the range specified in C2 of the present invention (&
18-), those in which the amount of Ru added is less than the range specified in the present invention (- (A 1 'S), and TM, R
For those (AzO) that did not contain u, a sample (-) was prepared in the same manner as in Example 1 above.

The characteristics of these samples (even if only one was available) were investigated in the same manner, and the results are also listed in Table 2.

From the results in the above table, it was found that the effective magnetic permeability and wear resistance were further improved due to the synergistic effect C2 with Ru. CoO,83Fe0.05 Ti0.0
2 Ruo, lo)? QS iHB6 6 amorphous alloy thickness: 30μm, 20μm, and 14μm
A thin ribbon was prepared in the same manner as in Example 1, and the dependence of the material thickness on the frequency characteristics of the effective magnetic permeability was measured. The measurement method was the same as in Example 1, 31 times.

The measurement results are shown in the graph of the drawing. As is clear from this graph, it was found that if the plate thickness was made thinner, the magnetic properties as a VTR magnetic head could be sufficiently satisfied.

As described in detail, according to the present invention, the addition of Ru has excellent wear resistance and high magnetic permeability, and the product with both Ru and TM added has even better properties. This makes it possible to obtain an improved amorphous alloy for magnetic heads.

[Brief explanation of the drawing]

The drawing is a graph showing the dependence of the frequency characteristics of the effective IA on the thickness of the material.

Claims (1)

[Claims] (1) At atomic concentration (Co_1-a-bFeaRub)_
1_0_0-x-ySixBy where 0.02≦a≦0.08 0.07≦b≦0.20 0≦x≦20 4≦y≦9 An amorphous alloy for a magnetic head. (2) At atomic concentration (Co_1-a-b-cFeaRub
TMc)_1_0_0-x-ySixBy However, TM is Ti, V, Cr, Mn, Ni, Zr, Nb,
Consisting of at least one of Mo, Hf, Ta, and W: 0.02≦a≦0.08 0.07≦b≦0.20 0.01≦c≦0.10 0≦x≦20 4≦y≦9 An amorphous alloy for magnetic heads characterized by: