JPS6239227B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a novel iron-based amorphous alloy for magnetic heads, and more particularly to an iron-based amorphous alloy for magnetic heads having high magnetic flux density, low magnetostriction, and high wear resistance. . [Technical background of the invention and its problems] Conventionally, high magnetic permeability materials used in magnetic heads include Fe--Ni alloy (permalloy) and Fe--Si--Al alloy (sendust), which have a crystal structure. . However, the Fe-Ni alloy has high magnetic permeability but poor wear resistance, and the Fe-Si-Al alloy has excellent wear resistance but is brittle, making plastic working very difficult. It had However, recently, excellent magnetic and mechanical properties have been discovered in amorphous alloys that do not have a crystalline structure. In particular, the atomic ratio of Co and Fe is 94:6.
Nearby cobalt-based amorphous alloys have magnetostriction near zero and high magnetic permeability, so they are attracting attention as materials for magnetic heads. However, the cobalt-based amorphous alloys generally have a low saturation magnetic flux density of 9 KG or less. Although it is possible to produce cobalt-based amorphous alloys of 9KG or more, in this case the Kyrie point (Tc) will be higher than the crystallization temperature (Tx), resulting in high magnetic permeability. This method is complicated in that it requires special treatments such as heat treatment in a rotating magnetic field. Furthermore, since it is based on cobalt, it is expensive and has the disadvantage of poor wear resistance. On the other hand, as an iron-based amorphous alloy, an alloy in which only Ru is added (Japanese Unexamined Patent Publication No. 43118/1983) is known, but magnetostriction is not taken into account in this alloy. In general, iron-based amorphous alloys have the advantages of being inexpensive and having high magnetic flux density, but on the other hand, they have large magnetostriction (low magnetic permeability) and are susceptible to deterioration of magnetic properties due to resin molding during the magnetic head manufacturing process. Due to serious problems, it has received little attention as a magnetic head material. Therefore, there has been a demand in the art for the development of an amorphous alloy that is inexpensive and has excellent properties for use in magnetic heads. [Objective of the Invention] The object of the present invention is to make an inexpensive iron-based amorphous alloy, which has high magnetic flux density, high magnetic permeability without the need for special heat treatment, and The object of the present invention is to provide a material for a magnetic head that also has excellent wear resistance. [Summary of the Invention] The present inventors have discovered that in an iron-based amorphous alloy, Ru
In addition to Ti, Hf, V, Nb, Ta, Cr, Mo or W
It has been discovered that by adding , the magnetostriction of the alloy is significantly reduced, resulting in high magnetic permeability and excellent wear resistance, and the present invention has been completed. The present invention is based on the following formula: (Fe _1-ab Ru _a M _b ) _100-c X _c [wherein M is Ti, Hf, V, Nb, Ta, Cr, Mo, W
represents at least one element selected from the group;
X represents B; a, b, and c are each 0.01≦a
Represents a number that satisfies the following relationships: ≦0.2, 0.02≦b≦0.1, and 10≦c≦18. ] and the following formula: (Fe _1-ab Ru _a M _b ) _100-c X _c [wherein M is Ti, Hf, V, Nb, Ta, Cr, Mo, W.
represents at least one element selected from the group;
X is B and Si [B is 10 atomic % or more, Si is 7 atomic % or less (however, 0 atomic % is not included)]
represents; a, b, c are each 0.01≦a≦
It represents a number that satisfies the following relationships: 0.2, 0.02≦b≦0.1, and 10≦c≦18. ] This invention relates to an iron-based amorphous alloy for magnetic heads. In the amorphous alloy of the present invention, Ru is an element effective in improving the wear resistance of the iron-based amorphous alloy and reducing magnetostriction, and the amount included:
a is expressed in atomic % and is set in the range of 0.01≦a≦0.2. When a is less than 0.01, the improvement in wear resistance is not significant, and when it exceeds 0.2, the saturation magnetic flux density is significantly reduced. Also, M(Ti, Hf, V, Nb, Ta, Cr, Mo,
W) is an essential component for lowering the magnetostriction of the iron-based amorphous alloy, and its included amount: b is expressed in atomic % and is set in the range of 0.02≦b≦0.1.
If b is less than 0.02, the decrease in magnetostriction is not significant, and if b exceeds 0.1, the saturation magnetic flux density is significantly decreased, which is not preferable. As element M, especially
Nb and Ta are effective. X (BB and Si) is an element effective in making the iron-based alloy amorphous, and its contained amount: c is expressed in atomic % and is set in the range of 10≦c≦18. If c is less than 10, it will be difficult to make the alloy amorphous, and if c is more than 18, the magnetostriction will not decrease significantly. In addition, X
In an amorphous alloy in which B and Si are B and Si, the ratio of B and Si is 10 at% or more for B and 7 at% for Si.
The following (however, 0 atomic % is not included): Here, Si is an effective element for facilitating the production of amorphous alloys, but it has the drawback of increasing magnetostriction, so the amount included is less than 7 atomic percent (however, 0 atomic percent). % is not included). To facilitate the production of amorphous alloys and reduce magnetostriction,
It is preferably 0.01 atomic % or more and less than 0.1 atomic %. The amorphous alloy of the present invention is produced by mixing the above-mentioned components in a predetermined ratio, melting the mixture, turning the mixture into an amorphous alloy by, for example, a liquid (molten metal) quenching method, and heat-treating as necessary. It can be easily manufactured by applying [Examples of the Invention] Example 1 (Fe ₀ . _95-b Ru ₀ . ₀₅ Nb _b ) An amorphous alloy having the composition shown by ₈₅ Si ₃ B ₁₂ was manufactured by a single roll method. That is, the alloy mixed with the above composition is melted, and then,
The molten alloy is placed on the surface of a single roll rotating at high speed,
Argon gas pressure (1.0~2.0Kg/
cm ² ), and the resulting ribbon was quenched to a width of 10
It was made into a long tape-like thin strip with a thickness of about 20 μm and a plate thickness of about 20 μm.
Next, the ribbon was cut to a length of 20 mm and used as a sample. The saturation magnetostriction of the above samples was measured by the strain gauge method. The results are shown in FIG. 1 as a relationship curve with composition ratio b. From the figure, it was found that as the composition ratio of Nb increases, the magnetostriction decreases significantly, and especially when b is 0.02 or more, the magnetostriction constant becomes 10×10 ⁻⁶ or less. Furthermore, in place of Nb, Ti, Hf, V, Ta, Cr,
Similar measurements were performed on an amorphous alloy with the above composition to which Mo and W were added, and the result showed behavior similar to that of Nb. Example 2 An amorphous alloy having _the composition _shown by (Fe ₀ . ₉₀ Ru ₀ . _{05 Nb 0} . It was measured. The results are shown in FIG. 2 as a relationship curve A with the composition ratio z. From the figure, the magnetostriction decreases significantly as z increases, and when z is 82 or more, the magnetostriction constant becomes 10×10 ^-6
It turned out to be the following. In addition, similar measurements were made for an amorphous alloy with the composition shown by FezSi _90-z B ₁₀ that does not contain Ru or Nb, and the results are plotted as relationship curve B with the composition ratio z according to Figure 2. Indicated. From these results, it is clear that Ru, Nb and
The effect of the addition of was found to be significant. Example 3 The amorphous alloy shown in the table was made into a long tape-like thin strip having a width of 10 mm and a plate thickness of about 20 μm using the single roll method in the same manner as in Example 1. This thin strip was cut to a length of 1 m, wound into a toroidal shape, and then heat treated in a temperature range above the Curie point and below the crystallization temperature.
It was used as a sample. Note that no rotating magnetic field treatment was performed. Regarding this sample, the effective magnetic permeability at 1 to 100 KHz was measured using a Maxwell bridge, the saturation magnetic flux density was measured using a sample vibrating magnetometer, and the saturation magnetostriction was also measured in the same manner as in Example 1. Effective magnetic permeability at 1KHz (〓′1K),
The values of saturation magnetostriction and saturation magnetic flux density are shown in the table. As comparative examples, amorphous alloys that do not contain Ru or M elements, and amorphous alloys that do not contain M elements are also shown in the table.

【table】

[Table] From these results, it was found that the amorphous alloy of the present invention has a low magnetostriction and therefore a high effective magnetic permeability. Example 4 The shape of an audio magnetic head was punched out from the ribbon obtained in Example 3, and a magnetic head was prototyped.
Their wear resistance was evaluated. The evaluation is γ-
This was done by measuring the amount of wear on the tape sliding surface of the magnetic head using a surface roughness meter before and after running a commercially available audio cassette tape coated with Fe ₂ O ₃ at a speed of 4.7 cm/sec for 100 hours. Ta. The amount of wear is also shown in the table. These results revealed that the amorphous alloy of the present invention has significantly improved wear resistance. [Effects of the Invention] The amorphous alloy of the present invention is inexpensive because it is mainly made of iron, and has a high effective magnetic permeability because of its low magnetostriction. Furthermore, no special heat treatment is required. Furthermore, it has characteristics such as a high saturation magnetic flux density and excellent wear resistance. Therefore, it has excellent suitability as a material for magnetic heads.
Its industrial value is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a relationship curve between the composition ratio b and saturation magnetostriction of the amorphous alloy of the present _invention represented by (Fe _0.95 − _b Ru _{0. 005} Nb _b85 Si ₃ B ₁₂₎ . Figure 2 is
(Fe _0.90 Ru _0.05 Nb _0.05 ) Relationship _curve A between the composition ratio z and saturation magnetostriction _of the amorphous alloy _of the present invention shown by _z Si ₈₈ − _z B ₁₂ and Fe _z Si ₉₀₋ It is a relationship curve B between the composition ratio z of an amorphous alloy represented by _Z B ₁₀ and the saturation magnetostriction.

Claims (1)

[Claims] Primary formula: (Fe _1-ab Ru _a M _b ) _100-c X _c [wherein M is Ti, Hf, V, Nb, Ta, Cr, Mo, W
represents at least one element selected from the group;
X represents B; a, b, and c are each 0.01≦a
Represents a number that satisfies the following relationships: ≦0.2, 0.02≦b≦0.1, and 10≦c≦18. ] An iron-based amorphous alloy for magnetic heads. Secondary formula: (Fe _1-ab Ru _a M _b ) _100-c X _c [In the formula, M is Ti, Hf, V, Nb, Ta, Cr, Mo, W
represents at least one element selected from the group;
X is B and Si (B is 10 atomic % or more, Si is 7 atomic % or less (however, 0 atomic % is not included))
represents; a, b, c are each 0.01≦a≦
It represents a number that satisfies the following relationships: 0.2, 0.02≦b≦0.1, and 10≦c≦18. ] An iron-based amorphous alloy for magnetic heads. 3 Of B and Si represented by X above, Si is
The iron-based amorphous alloy for a magnetic head according to claim 2, wherein the iron-based amorphous alloy contains 0.01 atomic % or more and less than 0.1 atomic %.