JPS5819121B2 - Manufacturing method of magnetic dielectric material - Google Patents

Description

[Detailed description of the invention] The present invention relates to a novel method for producing magnetic derivatives.

More specifically, the present invention relates to a method of producing a paste-like magnetic derivative by processing dielectric powder without using powder metallurgy.

Conventionally, magnetic derivatives are manufactured by powder metallurgy.

For example, Ferrai I is made by mixing refined fine powder of iron oxide with high-purity azalea oxide or manganese oxide, pulverizing the mixture to about 2 to 4 μm after calcining, adding a binder, and forming it into granules. , and is further manufactured by molding it into a desired shape and sintering it.

An object of the present invention is to provide a method for manufacturing magnetic dielectric materials by processing dielectric powder.

Another object of the present invention is to provide a method of processing a dielectric powder to produce a pasty magnetic dielectric.

Another object of the present invention is to provide a method for manufacturing a paste-like magnetic dielectric material by a physical method that avoids contamination of impurities during the manufacturing process.

The magnetic dielectric material of the present invention is produced by suspending a dielectric powder, particularly a dielectric powder with excellent abrasiveness, in water or an aqueous solution to form a suspension. It can be produced by polishing with dielectric powder in a suspension.

To explain in more detail, the magnetic dielectric material of the present invention is obtained by disposing the surface of non-magnetic austenitic stainless steel in an aqueous suspension of sized dielectric powder, for example, molten alumina powder.
This method is characterized by polishing with the dielectric powder, and a magnetic dielectric material can be obtained in the form of pasty powder.

The dielectric powder that is the raw material used in the production method of the present invention is a powder that has abrasive properties and dielectric properties, and preferably has
It is sized.

Examples of powders that have abrasive properties and dielectric properties include powders such as aluminum oxide, titanium oxide, iron oxide, chromium oxide, and barium titanate, but aluminum oxide is especially hard and difficult to polish. Excellent.

Furthermore, titanium oxide, barium titanate, and the like exhibit a high dielectric constant, and when these are used, a paste-like magnetic dielectric material with a high dielectric constant can be manufactured.

The sized corundum fine powder may be used alone or in combination with other dielectric powders.

The selection and composition of the dielectric powder can be appropriately determined depending on the desired magnetic dielectric material.

Since the selection and determination of the dielectric powder can be easily made by a person skilled in the art, the type and particle size thereof are not limited, but should be understood as self-evident.

That is, the particle size may be sufficient as long as it is sufficient to polish the surface of non-magnetic austenitic stainless steel in the suspension.

If the particle size is too fine, the abrasiveness is lost, but if the particle size is larger than the colloidal region, the abrasive effect is observed.

On the other hand, if the grain size is coarse, polishing becomes substantially difficult.

The dielectric powder having a dense structure has high abrasive properties.

On the other hand, those with a porous structure have a large surface area and have the advantage of having a large contact area with substances generated by polishing.

The dielectric powder must be used as a suspension in water or a desired aqueous solution.

The concentration of the suspension may be selected as desired.

In other words, since the dielectric powder only needs to polish the surface of non-magnetic austenitic stainless steel in the presence of moisture, it may be in the form of a paste or a relatively dilute suspension. .

That is, the solid concentration may be appropriately selected from the range of 0.5% to 90% by weight, but it is usually used as a suspension in the form of a slurry or paste.

When the surface of non-magnetic austenitic stainless steel is mechanically polished, the surface layer transforms into a ferromagnetic martensitic phase.

This property of austenitic stainless steel is applied to the production of paste-like magnetic dielectric materials.

By selecting and using a non-magnetic austenitic stainless steel that has the property of transforming into one with the desired magnetic properties, a paste-like magnetic dielectric material having the desired magnetic properties can be manufactured.

The shape of the non-magnetic austenitic stainless steel should be convenient for polishing.

In order to widen the polishing surface, it is desirable to have a plate shape, but in order to provide rotation, it is preferable to have a rod shape.

Furthermore, by using two non-magnetic austenitic stainless steel plates or steel rods and placing a suspension of alumina or the like between them and rubbing them together, fine particles of the stainless steel can be absorbed into the alumina suspension. It is possible to produce a paste-like substance that is dispersed in a similar manner.

That is, a slurry-like polishing liquid produced by polishing the surface of non-magnetic austenitic stainless steel using a dielectric powder suspension as an abrasive contains transformed magnetic martensite fine particles of the stainless steel and the dielectric powder. It is a colloidal substance consisting of fine abrasive particles and can be used as various magnetic dielectric materials.

The size of the altenside particles in the paste obtained by polishing non-magnetic austenitic stainless steel and an alumina suspension was approximately 5 OA, as measured from the half-width of electron diffraction reflection. Ta.

The content of metal components relative to the solid components of the pasty material obtained by polishing according to the present invention can be adjusted as appropriate depending on the degree of polishing.

Generally, polishing is performed so that the metal component content is 1 to 90% by weight, preferably 10 to 90% by weight.

In particular, it is preferable to use alumina as the dielectric powder because it has high abrasive properties.

Even when it is desired to use other dielectric powders such as barium titanate, it is desirable to mix such highly abrasive dielectric powders.

For example, by polishing malleable non-austenitic stainless steel with a suspension of sized alumina, a paste-like material containing both metal particles and oxide particles with a particle size of about 5 OA can be obtained. It was done.

In this manner, by adjusting the degree of polishing, it is possible to obtain a polishing product with a desired particle size and a desired blending ratio.

When producing a large amount of glue-like magnetic dielectric material according to the present invention, a round rod of non-austenitic stainless steel is attached to a rotating shaft and rotated, and a non-austenitic stainless steel plate or the like is provided in contact with the rod and slid. This contact surface can be polished while supplying the above dielectric powder suspension as an abrasive.

At this time, by circulating the dropped polishing liquid as a suspension, the metal content in the polishing liquid can be increased, and at the same time, the size of the particles in the polishing liquid can be made uniform.

The paste-like magnetic dielectric material produced by polishing non-austenitic stainless steel by the above method using a suspension of fused alumina fine powder abrasive material (lap solution) had a dielectric constant of about 10 Cgs. .

When a suspension in which titanium oxide, barium titanate, etc. is used in place of molten alumina is used, the dielectric constant of the pasty magnetic dielectric material is as follows.

It was significantly higher.

According to the method for producing a magnetic dielectric material of the present invention, the dielectric material can use high-purity dielectric powder as an abrasive material, and since it physically polishes non-austenitic stainless steel, the dielectric material can be physically polished. According to this method, a magnetic dielectric material can be manufactured without introducing impurities during the manufacturing process.

This physical manufacturing method is completely different from conventional chemical manufacturing methods.

Furthermore, the size of the particles of the magnetic dielectric material produced by the method of the present invention can be easily made uniform, and when the magnetic dielectric material is used as an electromagnetic material,
Generation of noise can be prevented.

In the method of the present invention, when malleable cast iron is used instead of non-austenitic streak stainless steel, the resulting paste-like cast iron magnetic dielectric material is significantly inferior in corrosion resistance compared to the magnetic dielectric material of the present invention, and It cannot be used inside for a long time.

On the other hand, the day containing elements that inhibit martensitic formation.

This industrial standard JIS 5US-321, SUS 316
-B.

When stainless steel such as 5US-347 is polished, a paste-like magnetic dielectric material with a small residual magnetism, that is, about 100 Gauss, is produced, but according to the method of the present invention, the spontaneous magnetization of the magnetic dielectric material obtained is ,about .

It reaches 5.000 Gauss.

Tapes made by applying the pasty magnetic dielectric slurry obtained by the process of the invention to a cloth ribbon together with a resin binder give extremely good results when used for magnetic recording.

・Since the magnetic fine powder particles of the magnetic tape are coated with dielectric powder, when used in a magnetic field,
There are fewer eddy currents, so the temperature rise of the magnetic tape is smaller, and the recording is more faithful.

The ferrite particles in conventional magnetic recording tapes have irregular sides and therefore have a small S/N ratio, but the magnetic recording tape using the magnetic dielectric material obtained by the manufacturing method of the present invention has a small particle size. It is easy to adjust the powder, and the S/N ratio can be increased.

In addition, magnetic recording tapes manufactured using magnetic dielectric materials manufactured using stainless steel containing a martensitic suppressing element, such as 5US-347, have a residual magnetism of approximately 100 cous or less, which is extremely small. So, once,
This has the advantage that it is extremely easy to partially erase recorded orders.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Non-magnetic austenitic stainless steel, 5US304 (
The end of a round bar made of 18% chromium, modulus 8 nickel steel, with a very small carbon content and having a diameter of 20 cr and a length of 100 mm was fixed at the center of the rotating shaft of a lathe and rotated at 500 to 1000 rpm.

A cut surface of a similar stainless steel round bar was brought into contact with this free end, and the contact surface was rotated while being pressed so that it was in friction.
) was added dropwise to perform co-printing.

The polishing liquid (lap liquid) obtained by this polishing was collected.

The recovered polishing liquid was supplied in circulation to increase the metal content in the polishing liquid.

The polishing liquid became pasty and grayish-black in color. ) According to the microscopic test results, it was observed that the stainless steel particles were uniformly dispersed.

This paste-like magnetic dielectric polishing liquid was found to be a magnetic material that responds to magnets.

As a result of repeated polishing with the polishing liquid, approximately 50% by weight of the solid component became a paste-like substance consisting of stainless steel fine particles.

This paste-like material was applied to the surface of a nonmagnetic metal, and the surface was observed using an electron beam reflection method.

As a result, the diameters of the stainless steel fine particles and alumina particles in the paste-like material were both about 50A, indicating that the particles and diameters were relatively uniform.

The content of each component in the solid component was confirmed by this test method.

Furthermore, magnetic and dielectric analysis using electron diffraction revealed that the generated magnetism was due to residual magnetism caused by austenite particles becoming martensite, and the dielectric property was due to charging due to alumina particles.

Example 2 According to the method of Example 1, a stainless steel plate (diameter 4 (yIIL)) of the same quality as a circular shape (diameter 60 CIfL) of non-magnetic austenitic stainless steel SUS 302 was used, and alumina of WA: # 1,500 was used as an abrasive. Working pressure 1
Rotary polishing was performed under a pressure of kg/crfL.

The resulting paste-like magnetic dielectric polishing liquid was tested for residual magnetism and dielectricity by the method of Example 1, and similar results were obtained.

Example 3 According to the method of Example 2, non-magnetic austenitic stainless steel (18% chromium-9 nickel niobium-0,
Polishing was carried out using a disk made of 0.6% carbon.

The resulting paste-like magnetic dielectric polishing liquid was tested for residual magnetism and dielectric properties by the method of Example 1, and as a result, the residual magnetism was extremely low.

This seems to be due to the influence of the martensite formation suppressing element Nb.

Claims (1)

[Claims] 1. A method of suspending dielectric powder in water or an aqueous solution to form a suspension, and polishing the surface of non-magnetic austenitic stainless steel with the dielectric powder in the suspension. Characteristic manufacturing method for magnetic dielectric materials. 2. The manufacturing method according to claim 1, wherein the dielectric powder is selected from aluminium oxide, titanium oxide, iron oxide, chromium oxide, and barium titanate. 3 Claim 1, characterized in that a mixture of aluminum oxide and other dielectric powder is used topically as a suspension.
Manufacturing method described in section. 4. The manufacturing method according to claim 1, wherein a non-magnetic austenitic stainless steel whose surface layer is easily transformed into a ferromagnetic martensitic phase by mechanical polishing is used. 5. The manufacturing method according to claim 1, using a non-magnetic autenitic stainless steel containing a martensitic formation inhibiting element.