JPH0128491B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to magnetic heads. Prior Art Thin plates of amorphous magnetic alloys have attracted attention as materials for magnetic heads due to their excellent soft magnetic properties, and research on their practical application is being actively conducted. An example of such an amorphous magnetic alloy thin plate composition for a magnetic head includes, in terms of atomic ratio, approximately Fe2 to 5 at%, Si1 to 5 at%, and B15 to 25 at%,
It is known that the remainder consists essentially of Co.
An amorphous magnetic alloy thin plate having such a composition has extremely low magnetostriction and an extremely high saturation magnetic flux density Bs of 7.5 KG or more. For this reason, if the head is constructed from such a material, a so-called magnetic powder made of metal powder such as Fe-Ni alloy or Fe-Co-Ni alloy, dispersed in a binder, and applied and installed. Effective recording can also be performed on high coercivity magnetic recording media such as metal tapes. However, the amorphous magnetic alloy thin plate having such a composition and the core for a magnetic head formed therefrom also have the following drawbacks. First, in order to manufacture a magnetic head from an amorphous magnetic alloy thin plate, it is preferable to punch out the thin plate into a predetermined shape and use this to construct the head. However, when such a thin plate as described above is punched using a die, cracks or so-called burrs occur on the sheared end surface, resulting in a poor yield. In addition, when the number of punched sheets increases, the die wears out and breaks, and as a result, burrs increase as the number of punched sheets increases, and one die can only punch tens of thousands of sheets, reducing productivity. bad. Moreover, when a magnetic head is manufactured by stacking such punched thin plates, the space factor decreases due to burrs at the ends, mechanical distortion remains, and the recording/reproducing output decreases. Furthermore, when the core for a magnetic head, such as a video head, is formed from only one thin plate without laminating thin plates, a process for removing the burr is required. Furthermore, there are problems with its wear resistance, especially
Then I configured the video magnetic head, etc.
When running in contact with a magnetic recording medium at high speed, the amount of wear is extremely large. There are also problems with its corrosion resistance, which causes wear due to chemical factors. In other words, when running in contact with a magnetic recording medium for a long period of time, the head may be damaged by the chemically corrosive atmosphere that the tape magnetic layer coating often has, or by carbon dioxide gas, moisture, etc. present in the air. A film of oxides or the like is formed on the surface of the constituent amorphous magnetic alloy material, and this peels off due to stress caused by running the tape or the abrasive action of the magnetic powder in the coating, causing head wear. This chemical wear is extremely severe not only under severe usage conditions such as high temperature and high humidity, but also under normal conditions. Additionally, when the head is stored or left unattended for a long period of time under conditions of relatively high temperature and humidity, a film is formed on the material surface due to the influence of moisture, and this film increases space loss. , the high frequency input/output level decreases during subsequent recording/reproduction use. In addition, due to sliding contact with the medium,
In particular, the film peels off near the headcap, increasing the effective gap or clogging the gap, which also lowers the high frequency input/output level. Furthermore, when recording and reproducing on so-called metal tapes that use the above-mentioned alloy magnetic powder, the input/output level in high frequencies decreases as the medium runs in contact with the tape, resulting in deterioration of frequency characteristics. . Furthermore, when used as a video magnetic head, the S/N ratio and resolution deteriorate. Such a phenomenon does not occur due to wear of the head surface, but is caused by the formation of a deteriorated layer on the head surface. And this altered layer is probably
It is thought that the metal magnetic powder and the amorphous magnetic alloy material that makes up the magnetic head undergo some kind of reaction, resulting in the attachment of altered substances of the alloy magnetic powder or the constituent elements of the amorphous magnetic alloy. . In addition, the plate thickness is large, making it difficult to obtain a thin plate with good surface properties. That is, when obtaining a thin plate by the single roll method according to the conventional method, especially when the plate thickness is 40 μm, for example,
If it exceeds this, the surface properties will become extremely poor. For this reason, when laminating thin plates to form a core for audio heads, attempts are made to increase the space factor.
When thin plates having a thickness of 40 μm or more, especially 45 to 120 μm are laminated, the space factor decreases due to the poor surface properties, and the recording/reproducing output decreases. In addition, for video heads, in order to prevent a drop in high frequency recording and reproducing efficiency due to secondary gaps during lamination, it is preferable to form the thin plates themselves without laminating them. To reduce wear, approximately twice the track width, at least 40μm
However, it is not possible to obtain a thin plate with such a thickness and good surface properties, resulting in various inconveniences. Purpose of the Invention The present invention has been made in view of the above-mentioned circumstances, and is an amorphous magnetic alloy thin plate having a composition as described above and having a high saturation magnetic flux density. When a magnetic head is formed by punching out such a thin plate, the various inconveniences mentioned above are to be solved. More specifically, the main effect of the present invention is that as a result of using a thin plate with good punchability and less punching burrs,
The magnetic properties do not deteriorate and the manufacturing yield is high, and it has excellent abrasion resistance, resulting in less wear even when magnetic recording media are run in contact at high speed.It also has high corrosion resistance and less wear due to chemical factors. It does not change in quality even when stored under poor conditions, and even when recording and playing back on metal tape, the frequency characteristics and S/N ratio do not deteriorate over time. Furthermore, it has a high Bs and has a good surface quality. An object of the present invention is to provide a magnetic head using a thin plate with good properties. The inventors of the present invention have repeatedly and intensively investigated these objectives, and have found that such objectives can be effectively achieved when a magnetic head is formed using a thin plate made by adding predetermined amounts of Ru and Cr. This is what led to the present invention. That is, the first invention is a magnetic head for a coated magnetic recording medium that uses metal powder as magnetic powder, and is made of an amorphous magnetic alloy thin plate having a composition represented by the following formula and having a sheared end surface. A magnetic head characterized in that it is formed from a blank. Formula (Fe _p Co _q Ni _{r ) x} Ru _{y Cr} z M _w (Si _{k B l} , and X represents one or more vitrifying elements other than Si and B. Also, x+y+z+w+v=100at%,
Among these, y is 0.01 to 8 at%, z is 0.5 to 8 at%, w is 0 to 4 at%, and v is 20 to 26 at%. Furthermore, p
+q+r=100%, k+l+m=100%, of which p is 3-7%, r is 0-10%, k is 0.5-20%, and m is 0-2%. ] Further, a second invention is a magnetic head that can be used both as a coating type magnetic recording medium using metal powder as magnetic powder and as a coating type magnetic recording medium using oxide powder as magnetic powder, which has the above formula. A magnetic head is characterized in that it is formed from a punched amorphous magnetic alloy thin plate having a composition represented by the following formula and having sheared end faces. Specific Configuration of the Invention Next, a specific configuration of the present invention will be described in detail. The iron group elements (Fe, Co,
The content x of Ni) is the sum of the respective contents y, z, w, and v of Ru, Ta, the above M, and vitrification elements (Si, B, and
It is the value subtracted from %, which is 54at% or more, 79.49at
% or less. In this case, the iron group elements include Fe and Co as essential components. And the Fe composition ratio p in the iron group element component is 3
7%, and the Co composition ratio q is 83 to 97%. Therefore, the Fe atomic ratio px obtained as the product of the atomic ratio x of the iron group element component and the Fe composition ratio p in the iron group element component is 1.6 to 5.6 at%, preferably 2.1 to 4.8 at%.
It is. If it is less than 1.6 at% or more than 5.6 at%, the magnetostriction becomes large and the magnetic permeability decreases. Further, the Co atomic ratio qx is 44.8 to 77.1 at%, more preferably 50 to 76 at%. If the value is other than this, the saturation magnetic flux density Bs decreases and becomes less than 7.5 KG, making it unsuitable for recording and reproducing on a high coercive force magnetic recording medium. Iron group element components include Ni in addition to Fe and Co.
may be included. However, as the amount of Ni increases, the saturation magnetic flux density Bs decreases, so the Ni composition ratio r in the iron group element component must be 10% or less, and the Ni atomic ratio rx must be 7at% or less. preferable. On the other hand, the content of vitrification element components is 20~
It is 26at%. As the vitrification element components, Si and B are essential components. In this case, the Si composition ratio k in the vitrification element component
is 0.5-20%, preferably 2.5-20%. And the Si atomic ratio kv is 0.1 to 5.2 at%, preferably
It is 0.5-5.0at%. When it becomes less than 0.1at%, Bs
The weight becomes less than 7.5KG, and the surface quality of the amorphous thin plate deteriorates, making it impossible to obtain a thin plate with good surface precision. On the other hand, if it exceeds 5.2 at%, the desired effects of the present invention cannot be obtained. That is, the abrasion resistance, corrosion resistance, punching workability, aging characteristics during use of the metal tape, and surface properties are insufficient. Furthermore, the saturation magnetic flux density Bs is also low when it is larger than 5.2at%. In this case, if the iron group element content x is increased and the vitrification element content v is set to a lower limit of about 20%, it may be possible to obtain Bs of about 7.5 KG. However, about 7.5KG
In the composition where Bs is obtained, the degree of amorphization is poor,
Moreover, a thin plate with good surface properties cannot be obtained. Further, heat treatment for removing strain after thinning the plate becomes difficult. On the other hand, the B composition ratio l in the vitrification element component is 78
~99.5at%, preferably 78-97.5at%, more preferably 78-95at%. And the atomic ratio lv of B is 15.6 to 25.9at%, preferably 15.6 to 25.3at%
%, more preferably 15.6 to 24.7 at%.
If it is less than 15.6at% or more than 25.9at%, the desired effect of the present invention will not be achieved as described above, and the
I can't get Bs. In this case, the Si composition ratio k/(k+
l) is preferably 0.2 or less, and more preferably 0.005 or more, more preferably 0.05 or more. and,
Even more favorable results are obtained when k/(k+l) is a value in the range of 0.08 to 0.2. Note that the vitrification element components include Si and B.
and as the above X, other vitrification elements,
For example, one or more of P, C, Ge, Sn, Al, etc. may be included. However, if the composition ratio m of X exceeds 2%, it becomes difficult to become amorphous, so the atomic ratio mv of X is 0.5 at% or less. On the other hand, in the amorphous magnetic alloy material of the present invention, the essential components are 0.01 at% or more and 8 at%
Contains the following Ru. If it is less than 0.01 at%, punching workability, wear resistance, corrosion resistance, aging properties when using metal tape, and surface properties are insufficient. Moreover, if it exceeds 8 at%, it becomes difficult to make it amorphous, the surface properties deteriorate, and the Bs becomes less than 7.5 KG. In this case, more preferable results are obtained when the Ru atomic ratio y is 1 to 8 at%, more preferably 2 to 6 at%. Furthermore, JP-A-52-114421 states that in the formula shown above, the content of the vitrifying element v = 25 at%, the composition ratio of Si and B in the vitrifying element k = 60%, l = 40%, atomic ratio of Si and B kv
An example of an amorphous magnetic alloy in which 2 at% of Ru is added, where 15at%, lv=10at%, and k/(k+l)=0.6 is described. However, with such materials,
Insufficient properties can be obtained in terms of wear resistance, corrosion resistance, punching workability, aging properties when using metal tape, and surface properties. And in such materials Cr
Even if they are used in combination, these properties are not significantly improved and the properties are insufficient. In particular, regarding punching workability, among the materials of the present invention, Ru and Ta
Both show lower values than those removed. This fact will become clear from the Examples and Comparative Examples described later. Further, the publication describes that Ru and Rh are additive elements that have the same effect in the Si-excess amorphous magnetic alloy thin plate as described above. However, in the material of the present invention with an excess of B shown by the above formula, when Rh is added instead of Ru, the wear resistance, corrosion resistance, punching workability, aging characteristics when using metal tape, and surface properties are insufficient. Only characteristics can be obtained. This fact will also become clear from the Examples and Comparative Examples described later. Further, the amorphous magnetic alloy thin plate represented by the above formula contains 0.5 to 8 at% Cr, more preferably 1 to 5 at% Cr, as an essential component. In this case, if it is less than 0.5 at%, high-speed abrasion is particularly large, and the punchability, deterioration of properties over time when using a metal tape, and even surface properties are not fully satisfied. Moreover, if it exceeds 7at%, Bs becomes 7.5KG or less, and it becomes difficult to make an amorphous thin plate. Note that such effects brought about by the addition of Cr are not achieved when Cr is replaced with W or Mo, which also belong to group VIB elements. This fact will also become clear from the Examples and Comparative Examples described later. On the other hand, the amorphous magnetic alloy material represented by the above formula contains transition metal elements other than iron group elements, Ta, Ru, and Cr (Sc~Zn; Y~
Cd; La to Hg; Ac or more) may be included. However, if M exceeds 4 at%, Bs decreases and the effects of the present invention are diminished. And the atomic ratio of M is 0 to 2at%
It is preferable that Preferred examples of such other transition metal elements M include Ti, Zr, Hf, V, Nb, Mo, W,
One or more types such as Mn can be mentioned. In addition,
Ta is excluded from the present invention because the present applicant proposed it as an earlier application of this application. The amorphous magnetic alloy thin plate of the present invention having the composition shown in the above formula described in detail above is in an amorphous state with substantially no long-range regularity. The thickness of such a thin plate is usually about 10 to 200 μm. In this case, the plate thickness is preferably 40 μm or more, particularly 45 μm or more, in that the surface properties are even better than in other compositions. However, if the plate thickness exceeds 120 μm, the surface properties will deteriorate, so the plate thickness is preferably 45 to 120 μm. Such an amorphous magnetic alloy thin plate is usually manufactured as follows. That is, an alloy of a corresponding composition is ultra-quenched from the gas phase or liquid phase. In this case, the alloy is usually used as a melt, and the temperature is 10 ⁴ °C/sec or more from the liquid phase, usually 10 ⁴
An amorphous magnetic alloy thin plate is obtained by ultra-quenching and solidifying at a cooling rate of ~10 ⁶ °C/sec. In order to super-quench a molten alloy, the molten alloy may be injected from a nozzle and quenched according to various known methods such as a twin roll method, a single roll method, and a centrifugal quenching method, particularly a single roll method. Such amorphous magnetic alloy thin plates are preferably laminated with an insulating adhesive layer interposed therebetween to form core halves of a desired shape, and these are butted together to form a core for a magnetic head, particularly for an audio device, etc. It is used as a core for magnetic heads. Alternatively, the thin plates themselves are not laminated, but the thin plates themselves are formed into core halves of a desired shape, and the core halves are butted together to form a core for a magnetic head, particularly for a video magnetic head. In this case, the sheet metal is formed from a stamping with a sheared cross section. That is, when the core for a magnetic head of the present invention is formed as a laminated core, or when the core is formed without laminating the thin plates themselves, all or part of the end surfaces of the thin plates constituting the core are coated with A shear plane exists. As a result of being formed in this way, the punchability of the thin plate of the present invention is extremely good as described above, so that when the core for a magnetic head of the present invention is used as a laminate, the space factor is improved, Output increases.
In addition, good characteristics are exhibited even when the core is formed from only one thin plate. Furthermore, productivity is improved. Such a core for a magnetic head is usually manufactured as follows. First, preferably, a predetermined heat treatment is performed on a thin plate obtained by an ultra-quenching method. This heat treatment may be, for example, annealing in a non-magnetic field at a temperature below the crystallization temperature and above the Curie point, particularly for the purpose of eliminating internal strain, or annealing at a temperature below the crystallization temperature and the Curie point. It may also be annealing treatment in a magnetic field for the purpose of removing strain and improving magnetic properties. For this latter annealing treatment in a magnetic field, either a static magnetic field, a rotating magnetic field, or the like may be used. These annealing heat treatments and their conditions may be appropriately selected from the composition of the amorphous magnetic alloy and the desired magnetic properties. Next, such thin plates are cut out using a mold to form a predetermined shape, and usually, a plurality of the sheets are laminated with an insulating adhesive so as to have a predetermined track width to form a laminated core half for audio, etc. Create.
In this case, the amorphous magnetic alloy material of the present invention has good punching workability, and there are very few cracks and burrs on the sheared end surface, and this punching process can be used to efficiently and with high yield. You can get a body. Furthermore, since there are few burrs, the space factor is high, and the recording/reproducing output does not decrease. Note that the above heat treatment may be performed after this punching. In addition, especially when used as a magnetic head for video, it is usually sufficient to use thin plates with a thickness of 40 μm or more with good surface properties without laminating them. After punching this into a predetermined shape, the front surface is A core half is obtained by grinding to the track width. After this, the core halves are usually wound, inserted into a core holder, the gap abutting surfaces are polished, and then a gap forming material is placed in the gap with a predetermined gap, and the core halves are connected to each other. Butt, core and no, and store in a shield case,
A magnetic head is manufactured by resin molding. The magnetic head produced in this way can be used when recording and reproducing data from a coated magnetic recording medium that uses metal magnetic powder, or when it is used in conjunction with a coated magnetic recording medium that uses oxide magnetic powder. This is useful when recording and reproducing. It is extremely useful in any application, particularly as a contact type head for audio, video, electronic computers, card readers, and the like. Specific Effects of the Invention The amorphous magnetic alloy thin plate used in the present invention is
The punching processability is extremely good, no cracks occur on the single sheared surface, the burrs caused by punching are also extremely small, the punching yield is high, and the number of punched pieces that can be punched using the same mold is also low. There will be significantly more. Therefore, the magnetic head of the present invention formed from such a thin plate punched body does not have a decrease in space factor due to burrs or a decrease in recording/reproducing output. Moreover, as a result of being able to perform punching with high productivity as described above, productivity is good and manufacturing costs are low. In addition, the thin plate used in the present invention has a high saturation magnetic flux density Bs, and the magnetic head of the present invention has extremely favorable characteristics as a head for recording and reproducing high coercive force media such as metal tapes. In addition, the magnetic head of the present invention has high wear resistance,
Even when configured as a video head, the amount of wear under high-speed contact running is extremely small. Moreover, its corrosion resistance is high, chemically caused wear is low when the medium runs in contact with it, and the high-frequency input/output level decreases very little even when stored under poor conditions. Furthermore, even when running in contact with a high coercive force medium using alloyed magnetic powder called metal tape, a degraded layer is generated and the frequency characteristics and S/
The N ratio and resolution do not deteriorate over time. Furthermore, the thin plate used in the present invention has extremely good surface properties, and the magnetic head of the present invention exhibits good characteristics. In particular, when using a thin plate with a thickness of 40 μm or more, the surface properties are much better than other types, and for this reason, when used as a laminated core, the space factor is extremely high and high output can be obtained. Another feature is that it is possible to obtain a core with good properties using a single thin plate without laminating layers. Hereinafter, the present invention will be explained in more detail with reference to Examples, Experimental Examples, and Comparative Examples. Example 1 Long thin plates of 15 mm width and 50 μm thickness of amorphous magnetic alloys having 11 different compositions as shown in Table 1 below were produced by a high-speed quenching method using a single roll method. Next, for each of these thin plates 1-1 to 1-11,
Heat treatment was performed in a non-magnetic field at a temperature above the Curie point and below the crystallization temperature, respectively. Saturation magnetic flux density for each thin plate 1-1 to 1-11
When Bs was measured, the results shown in Table 1 were obtained. In addition, the surface properties of each thin plate were evaluated. That is, each thin plate is cut into a predetermined length, the difference between the maximum and minimum thickness in the width direction, that is, the maximum surface roughness, is measured, this is repeated over the entire longitudinal direction, and the average value of each thin plate is determined. surface roughness. The results are shown in Table 1. Thereafter, each of the thin plates 1-1 to 1-11 was punched into the shape of a video head core half using a cemented carbide die. In this case, the core halves were shaped like a C-shape on one side and a D-shape on which a wire could be wound, similar to those in known ferrite or Sendust video heads. For each thin plate 1-1 to 1-11 and for each core half, the same mold was used to make 11
We punched out 10,000 pieces. For each thin plate, a total of 10 punched pieces were selected from the 100,000th sheet, and the height of the burr on a single punched surface was measured using an electric micrometer. Table 1 below shows the results of averaging these results and further averaging them for each core half punched body. Next, a video head was produced using the core half punched bodies obtained from each of these thin plates 1-1 to 1-11. That is, after grinding the tip of the punched body for one core half to a predetermined track width and thickness, the tip gap surfaces of both core halves are polished to a mirror finish, and a gap forming material is applied to the gap surfaces.
SiO ₂ was vacuum deposited to a predetermined thickness. After this, the two core halves were butted together and glued together to form a video head. A total of 11 types of video heads were prepared in this way using commercially available chrome position type video tapes containing Co-doped γ-Fe ₂ O ₃ as magnetic powder.
%, it was run for 100 hours at 5.5m/Sec. Table 1 shows the results of measuring the depth of wear on the entire surface of the head after running using a surface roughness meter. On the other hand, apart from this, each of the thin plates 1-1 to 1-
An audio head was manufactured using No. 11. That is, first, from each of the thin plates 1-1 to 1-11, a substantially C-shaped core half was punched out using a die, and these were laminated to a thickness of 0.6 mm.
Got half a core. In this case, almost the same results as above were obtained regarding the height of burrs on the punched body. Next, each core half was wound and housed in a core holder, and the gap abutting surfaces of the core halves were mirror-finished. These were then butted together with a predetermined gap gap according to a conventional method to obtain a total of 11 types of audio heads. A total of 11 types of audio heads thus obtained were left to stand for 200 hours at 40° C. and 95% relative humidity to perform a storage stability test under harsh conditions. After standing, a commercially available coating type γ using a vinyl chloride thermoplastic binder and γ-Fe ₂ O ₃ as magnetic powder was applied.
-Tape at a running speed of 4.75cm/sec and 20g
Contact running was performed with an applied pressure of . At that time, 14kHz
The playback sensitivity was measured and the change from the output level before measurement was calculated. The results are shown in Table 1. Separately, the 11 types of heads mentioned above were evaluated for chemical wear under poor conditions. In other words, the above γ under the conditions of 40℃ and 95% relative humidity
- Using the tape, the tape was run for 1000 hours under the same conditions as above, and the depth of wear on the front surface of the head after running was measured using a surface roughness meter. The results are shown in Table 1. Furthermore, using a commercially available metal tape using Fe-Ni alloy magnetic powder, it was heated at 25℃ and 50% relative humidity.
It was run for 2000 hours at 4.75cm/sec. After running for 2000 hours, the frequency characteristics of 315Hz/14KHz were measured using a standard tape containing γ-Fe ₂ O ₃ as magnetic powder. The results are expressed as the deterioration value (F
Specific degradation: dB) is also listed in Table 1.

【table】

[Table] From the results shown in Table 1 above, it is found that the
Thin plate 1-3 containing a predetermined amount of Ru and a predetermined amount of Cr
It can be seen that only samples No. 1-6 and Nos. 1-8 to 1-11 exhibited good punchability and small burrs. It is also seen that only the thin plates belonging to the present invention exhibit good surface properties. Furthermore, it shows good Bs. The magnetic head core of the present invention, which is constructed from such a thin plate punched body, has excellent abrasion resistance, extremely low high-speed wear, excellent corrosion resistance, storage stability under poor conditions, and chemical resistance. It can be seen that the amount of wear on the metal tape is extremely small, and the deterioration over time during use of the metal tape is also extremely small. Experimental Example 1 In order to further confirm the good surface properties of the thin plate according to the present invention, the following experiment was conducted. That is, an amorphous magnetic alloy thin plate A having a composition of (Fe ₅ Co ₉₅ ) _70.25 Ru ₄ Cr ₃ (Si ₁₀ B ₉₀ ) _22.75 belongs to the present invention, and an amorphous magnetic alloy thin plate A that does not contain Ru and Cr and does not belong to the present invention (Fe ₅ Co ₉₅ ) ₇₈ (Si ₁₀ B ₉₀ ) ₂₂
A long thin plate with a width of 15 mm was produced using amorphous magnetic alloy thin plate B having a composition of 1. In this case, the thickness of each thin plate A and B is
Various thin plates A and B with different thicknesses were obtained by changing the thickness in the range of 20 to 100 μm. The surface roughness of each obtained thin plate was measured as follows. That is, each thin plate is cut into a predetermined length, and the difference between the maximum and minimum thickness in the width direction, that is, the maximum surface roughness, is measured. surface roughness. The results are shown in Figure 1. In the figure, curve a is thin plate A,
Curve b is the result for sheet B. From the results shown in FIG. 1, it can be seen that thin plate A having a composition belonging to the present invention exhibits better surface properties than thin plate B. In particular, when the plate thickness is 40 μm or more, the difference in surface properties is extremely significant. Example 2 Having the composition shown in Table 2 below, 50 μm thick, 15 mm
Amorphous magnetic alloy thin plates 2-1 to 2-8 of five different widths were obtained. Table 2 shows the Bs of each thin plate, the surface roughness measured in the same manner as in Example 1, and the punching burr at the 100,000th sheet.
Shown below. Further, a video head was prepared from each thin plate in the same manner as in Example 1, and the amount of high-speed wear measured in the same manner as in Example 1 is shown in Table 2. Furthermore, audio heads were made from each thin plate, and γ-Fe ₂ O ₃ was used as magnetic powder for each head.
Commercially available γ- using vinyl chloride acetate binder
The tape was used to measure the amount of chemical wear under normal conditions. In other words, this γ-tape is
With a running speed of 4.75cm/sec at ℃ and 50% relative humidity.
It was run for 1000 hours with an applied pressure of 20g. The wear depth after running was measured using a surface roughness meter. The results are shown in Table 2. In addition, a preservability test was conducted on each audio head in the same manner as in Example 1. The results are shown in Table 2.

[Table] From the results shown in Table 2, thin plates 2-1 to 2-3
and thin plates 2-4 to 2 belonging to the present invention
-7, when the Si content in the vitrification element exceeds 20%, even if Ru and Cr are added, the punchability, surface properties, and abrasion resistance are particularly poor. It can be seen that only extremely poor characteristics can be obtained. On the other hand, the thin plates 2-4 to 2-2 belonging to the present invention
When No. 7 is used, each characteristic is extremely good. On the other hand, if the Si content in the vitrification element component is 0.5
% or less, the punchability, surface properties, and abrasion resistance are extremely poor. Note that, as in Example 1, the head of this example did not produce a deteriorated layer after running with the metal tape for a long time, and the F
In particular, it was confirmed that there was no deterioration over time in the S/N ratio or resolution. Comparative Example Amorphous magnetic alloy thin plates 3-1 to 3-3 having the compositions shown in Table 2 and having a thickness of 50 μm and a width of 15 mm were obtained. Table 2 shows the surface roughness and punching burr of the 100,000th sheet of each thin sheet Bs, which were measured in the same manner as in Example 1. Table 2 also shows the high-speed abrasion properties of video heads obtained in the same manner as in Examples 1 and 2, as well as the amount of chemical wear and storage stability of audio heads. . From the results in Table 2, it can be seen that the desired effects of the present invention cannot be obtained when Ru is replaced by Rh and when Cr is replaced by Mo or W.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining one effect of the present invention, and is a diagram showing the relationship between the thin plate thickness and surface roughness of an amorphous magnetic alloy thin plate belonging to the present invention.

Claims (1)

[Scope of Claims] 1. A magnetic head for a coated magnetic recording medium using metal powder as magnetic powder, which has a composition represented by the following formula and is made of an amorphous magnetic alloy thin plate having a sheared end surface. A magnetic head characterized in that it is formed from a blank. Formula (Fe _p Co _q Ni _{r ) x} Ru _{y Cr} z M _w (Si _{k B l} , and X represents one or more vitrifying elements other than Si and B. Also, x+y+z+w+v=100at%,
Among these, y is 0.01 to 8 at%, z is 0.5 to 8 at%, w is 0 to 4 at%, and v is 20 to 26 at%. Furthermore, p
+q+r=100%, k+l+m=100%, of which p is 3-7%, r is 0-10%, k is 0.5-20%, and m is 0-2%. 2. The magnetic head according to claim 1, which is formed by butting core halves formed by laminating thin plate punched bodies. 3. A magnetic head according to claim 1, in which the thin plate punch itself is used as a core half, and the core halves are butted against each other. 4. A magnetic head that can be used both as a coated magnetic recording medium that uses metal powder as magnetic powder and as a coated magnetic recording medium that uses oxide powder as magnetic powder, and has a composition represented by the following formula, A magnetic head characterized in that it is formed from a punched body of an amorphous magnetic alloy thin plate having a sheared end surface. Formula (Fe _p Co _q Ni _{r ) x} Ru _{y Cr} z M _w (Si _{k B l} , and X represents one or more vitrifying elements other than Si and B. Also, x+y+z+w+v=100at%,
Among these, y is 0.01 to 8 at%, z is 0.5 to 8 at%, w is 0 to 4 at%, and v is 20 to 26 at%. Furthermore, p
+q+r=100%, k+l+m=100%, of which p is 3-7%, r is 0-10%, k is 0.5-20%, and m is 0-2%. ]