JPS6043486A - Wear-resistant "sendust(r)" alloy and its production - Google Patents

Abstract

PURPOSE:To form a thin film of hard carbon or diamond on the surface of a ''Sendust'' alloy part and to improve the wear resistance thereof without decreasing the magnetic characteristic thereof by conducting electricity to said part in a vessel to heat the part and bringing gaseous hydrocarbon or pulverous carbon powder activated by high-temp. heating into contact therewith. CONSTITUTION:A part 1 formed of a ''Sendust'' alloy as an Fe-Si-Al high permeability alloy is supported at both ends by movable supporting bars 2 and is disposed in a vessel 6. The inside of the vessel 6 is evacuated through an evacuating port 4 and electricity is conducted through both bars 2 to the part 1, thereby heating said part to 200-700 deg.C. Gaseous hydrocarbon such as methane, benzene or the like or pulverous carbon is passed through a W filament 5 kept at a high temp. of 2,200 deg.C and is thus activated by heating. The activated hydrocarbon or pulverous carbon is deposited by evaporation on the surface of the alloy 1 in the form of a thin film of hard carbon or diamond, by which the wear resistance of said alloy is remarkably improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to the improvement of Fe-5i-AI based high magnetic permeability alloys, so-called sendust alloys, and particularly (2) improving the wear resistance of the surface of conventional sendust alloys. By being supervised by a thin film of
It has a high degree of wear resistance without impairing its magnetic properties.

[Technical background of the invention and its problems]

Sendust alloys have high magnetic properties, especially magnetic flux density,
It has excellent magnetic permeability, high magnetic permeability at high frequencies, and good corrosion resistance in the atmosphere, so it is suitable for magnetic head cores in stereos, VTRs, and other electronic devices that do not require high magnetic properties. It is attracting attention as a suitable ladle.

However, conventional Sendust-based alloys have poor wear resistance, and for example, magnetic helad cores made of Sendust-based alloys are subject to wear and thinning due to contact with the magnetic tape, resulting in poor recording and playback sensitivity due to a decrease in the degree of contact. , QJ a maintained good performance over a long period of time. In particular, in the case of broadcasting VTRs, etc., the relative speed between the magnetic tape and the magnetic head is high, so the above problem becomes more serious.

To deal with this, so far, Cr has been added to form a passive film on the alloy surface, and Ti
, Zr, rare earth elements, etc. have been proposed. However, although these methods slightly improve wear resistance, they are still not fully satisfactory for stable long-term use.

[Purpose of the invention]

The present invention was made in view of these conventional problems, and provides a sendust alloy having excellent wear resistance and a method for producing the same.

[Summary of the invention]

The typical composition of the sendust alloy used in the present invention is 1
Although it is composed of 9.6% silicon, 5.4% aluminum, and the balance iron in weight ratio, it may be possible to slightly change the composition of silicon and aluminum, or to add a third element such as Cr or Zr.

The present invention was made by focusing on the fact that hard carbon or diamond is extremely hard and can be synthesized into a film-like material relatively easily. When a thin film made of at least one of hard carbon and diamond is formed on the surface of a Centast alloy, the hardness of the thin film is extremely high, and almost no wear is observed under normal usage conditions.

Therefore, the sendust alloy substrate is also not subject to wear.

In general, when considering the mechanism of wear at the atomic or molecular level, wear occurs when a strong frictional force acts over a wide area of the surface of an object, so the thin film mentioned above also microscopically closes over the entire surface of the sendust alloy. It does not have to be formed on the entire surface in a macroscopic sense, and the function will be fully exerted if it is formed on the entire surface, but in order to minimize wear and tear on the mating material, it is better to be microscopically tight. desirable.

Next, a method for manufacturing a wear-resistant sendust alloy according to the present invention will be described. When hydrocarbon gas such as methane or benzene or carbon is activated by heat, microwave solar discharge, ion beam, etc. and allowed to act on the sendust alloy, at least one of hard carbon or diamond is deposited on the surface of the sendust alloy. . In this case, the activated hydrocarbon gas or carbon is used so that the vapor deposition progresses uniformly on the surface of the sendust-based alloy and a thin film of at least one of hard carbon and diamond grows uniformly. and the relative position of the sendust alloy. At present, the mechanism by which at least one of hard carbon or diamond is precipitated from the activated hydrocarbon gas or carbon is not clear, but it is probably that when the hydrocarbon gas or carbon is activated by the above method, the sP3 hybrid orbital is formed. It is thought that atomic carbon having the following properties is generated, and is precipitated on the surface of the substrate while maintaining the SP8 hybrid orbital due to the medium action of the substrate such as the sendust alloy. As estimated from the fact that diamond, the hardest existing material, is an aggregate of sPs hybrid orbital carbons, it is thought that bonds between carbons in the sP3 hybrid orbital generally result in a material with high hardness.

〔Effect of the invention〕

It is clear that the present invention provides a dust-based alloy with excellent wear resistance. Therefore, the life ψ performance of the sendust alloy is greatly improved.

The manufacturing method is also extremely simple, and the manufacturing method according to the present invention can be implemented after the manufacturing process of conventional sendust-based alloy parts, so there is no need to significantly change the conventional process.

Thin films made of at least one of hard carbon or diamond have excellent corrosion resistance in the atmosphere, so
The sendust alloy according to the present invention is.

Compared to conventional sendust alloys, it has almost the same corrosion resistance in the atmosphere.

In the use as a magnetic head core, which is one of the main uses of Sendust alloys, the magnetic head core is made of magnetic tape (usually made of organic synthetic resin, containing chloride ions, carbon dioxide, etc.).
The sendust alloy according to the present invention is corroded by the eluted CI- when it comes into contact with the eluted CI-.
It also has excellent corrosion resistance against CI- and maintains excellent performance under actual usage conditions.

[Embodiments of the invention]

Hereinafter, the present invention will be explained using Examples, but the Examples are not intended to limit the present invention in any way.

After finishing and polishing the surface of the Sendust alloy with #10,000 iron oxide powder, it was washed with water and ethanol.

Dry. A thin film made of at least one of hard carbon and diamond was formed on the surface of the Sendust alloy thus obtained using the apparatus shown in FIG. 1 in the following manner. The sendust alloy 1 is placed in a container 6, both ends of the sendust alloy are supported by the movable support rods 2, and then the sendust alloy is placed in the container 6.
The inside of the was exhausted from the exhaust port 4. Next, by passing an electric current through the movable support 2, the sendust alloy 1 is
Electrical heating was carried out at 0θ to 700°C. Next, an electric current was passed through the tungsten filament 5 to heat it to about 2,200" O2, and then methane was introduced from the gas port 3. The methane was heated and activated by the tungsten filament 5, and formed into a film as hard carbon or diamond on the sendust alloy 1. During this precipitation process, the movable support rod 2 is used to slowly move, for example, a flat plate-shaped sendust alloy in the y-z plane, so that at least one of thin hard carbon or diamond is deposited over the entire predetermined surface. (Here, the axis connecting the sendust alloy l and the tungsten filament 5 is the X axis, the axis connecting the two movable support rods 2 is the y axis, and both the X and y axes are The axis perpendicular to this is the 2nd axis).

Even with other shapes of sendust alloys, it is possible to form a uniform thin film using an appropriate method. For example, in the case of a round rod-shaped Sendust alloy, the Sendust alloy is slowly rotated around its long sleeve using the movable support rod 2, and slowly moved parallel to the long axis direction. A thin film of at least one of hard carbon and diamond can be formed over the entire outer surface. It was confirmed by Auger electron spectroscopy, electron beam diffraction, etc. that the thin film was made of at least one of hard carbon and diamond. In order to investigate the wear resistance of the Sendust alloy according to the present invention thus obtained, the wear resistance in the atmosphere against a commercially available magnetic tape was measured at a contact pressure of 0.5 MPa, a speed of 7 m/s, and a friction distance of 30.
Tested under conditions of 0.00 km.

As a result, the amount of wear was 1 mg/dm2, and the surface condition of the sendust alloy hardly changed before and after the test.
It has been revealed that it exhibits excellent wear resistance.

For comparison, the wear resistance of a conventional sendust alloy was similarly investigated and the wear amount was 800 mg/dm2.

Furthermore, the magnetic properties of the sendust alloy according to the present invention are at a level almost equivalent to that of conventional general sendust alloys, and the effective magnetic permeability at 1 kHz, for example, showed a value of 51.000.

As is clear from the above, the method for manufacturing the wear-resistant sendust alloy according to the present invention is extremely simple and inexpensive. Further, the wear-resistant sendust alloy obtained by the present invention exhibits excellent wear resistance and is suitable as a material for magnetic helad cores that require high wear resistance, such as stereos and VTRs.

In the above example, by passing an electric current through the movable support rod 2, the sendust alloy 1 was heated to about 200 to 7
The reason for heating with electricity to 00° C. is to promote uniform and rapid precipitation of hard carbon or diamond on the surface of the sendust alloy. Also, increase the temperature to 200℃
The reason for limiting the temperature to ~700°C is that at temperatures below 200°C, it takes a long time to obtain a thin film of the desired thickness, and when it exceeds 700°C, by-products may be mixed in and the film thickness may increase undesirably.
This is because it was observed that the magnetic properties of the resulting sendust alloy were reduced.

So far, I have talked about sendust alloys.

The manufacturing method of the present invention can also be applied to magnetic materials that require wear resistance, such as permalloy ferrite, to obtain materials with excellent wear resistance. Moreover, not only crystalline alloys but also amorphous alloys can be produced with excellent wear resistance by the manufacturing method according to the present invention.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an apparatus system for producing a wear-resistant sendust alloy according to the present invention. 1. Sendust alloy 2. Movable support rod 3. Gas inlet 4. Exhaust port

Claims (2)

[Claims] (1) A wear-resistant Sendust alloy characterized by having a thin film made of at least one of hard carbon and diamond on the surface of the Sendust alloy. (2) By applying at least one of activated hydrocarbon gas or carbon to the sendust alloy and changing the point of action, the surface of the sendust alloy is made of at least one of hard carbon or diamond.゛A method for producing a wear-resistant sendust alloy, which comprises uniformly forming a thin film.