JPS60239906A - Magnetic head - Google Patents

Abstract

PURPOSE:To decrease wear of an aluminum reinforcing plate itself and to prevent damage to a medium by joining the reinforcing plate formed with a crystalline alumina layer on the surface to at least one side surface of a core consisting of a magnetic metallic material. CONSTITUTION:Ferrite, ''Sendust(R)'', amorphous alloy, etc. are used for the magnetic metallic material 2 to be used as the core for a magnetic head. The reinforcing plate 2 is disposed on at least one side of the core. Aluminum or aluminum alloy is used as the blank material for the reinforcing plate and a film of eta alumina or alpha alumina is formed 10-50mu on the aluminum alloy. The head joined with the reinforcing plates subjected to said treatment on both sides wears hardly even after 1,000,000 times of contact with a tape at 6m/sec relative speed and since the alumina film is porous, the level of the damage to the medium is extremely small.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a laminate type magnetic head.

[Prior art]

In recent years, as the recording density in magnetic recording has increased, the recording track width has become narrower, and track widths of 5 μm or less are now being used.

1- On the other hand, with the appearance of high-resistance catheters such as metal tapes, the appearance of magnetic heads using metal magnetic materials such as sendust, which have a higher saturation magnetic flux density than conventional ferrite video heads, is eagerly awaited. However, metal magnetic materials generally have lower resistivity than ferrite.
Therefore, the attenuation in the high frequency range due to the skin effect is large, so in order to bring out sufficient performance, the thickness of the head core needs to be several tens of micrometers. ? : As the head core became thinner, it became necessary to join some kind of reinforcing plate to at least one side of the core in order to strengthen the core and configure it as a head. Conventionally, glass and ceramics have generally been used as materials for this reinforcing plate.

However, among these materials, there is no material that has both the characteristics of lubrication resistance for magnetic media such as tape and resistance to wear itself. The shape was claimed to be a material with excellent properties for m/sec and delicious things.

2- [Purpose] The present invention is intended to solve these problems, and its purpose is to use a material with both wear resistance and lubricity for the reinforcing plate in the above-mentioned laminate type head. This is about the head that was used.

〔overview〕

The present invention provides a magnetic head in which an aluminum reinforcing plate with a crystalline alumina layer formed on the surface is bonded to at least one side of a core made of a metal magnetic material, and a reinforcing plate in which a lubricant is sealed in the alumina porous layer. It is characterized by using

〔Example〕

Hereinafter, the present invention will be described in detail based on examples.

FIG. 1 is a schematic structural diagram of a normal laminate type head. Ferrite, sendust, amorphous alloy, or the like is used as the metal magnetic material 1 serving as the core, and a reinforcing plate 2 is provided on at least one of the cores. In this head, aluminum or aluminum alloy is used as the material for the reinforcing plate.

When this aluminum is anodized in sulfuric acid or oxalic acid,
Usually an amorphous alumina film is formed, but
The present invention forms a crystalline alumina film instead of an amorphous alumina film by performing the oxidation under the following conditions. There are two types of crystalline alumina films, one is eta alumina and the other is alpha alumina.

The α-alumina film forming conditions are shown below.

Bath composition: carbonic acid) IJum 2 mol/dm” Solution bath voltage: 150-1.80 V Dc bath temperature: 30
~80°C Processing time: 5 to 20 minutes Next, the conditions for forming the α-alumina film are shown below.

a)-Next treatment bath composition Sulfuric acid 2,76rn, ol/dm Current density 100~Den2 Temperature 25℃ Treatment time ~30 minutesb) Secondary treatment 4-Porous alumina film in aqueous solution of metal salt The formed material is immersed and metal ions are introduced into the bore. Examples of metal ion introduction conditions are shown below.

Bath composition (NH4)2 Cro45 x 1(1-”
mol/rim3 Temperature: 60° C. to 70° C. Time: 20 to 40 minutes Next, a lath spark discharge of an alumina film containing metal ions is performed in the molten salt under the following conditions.

Bath composition Sodium bisulfate and ammonium bisulfate in a molar ratio of 1:1.15 Salt temperature 170℃ Current density 100A/m" Treatment time 1 (1 to 30 minutes) ，
A porous film having the structure of 03 can be formed.

This film has a Vickers hardness of Hυ=1500 or more.

A film of η alumina or α alumina described above is formed to a thickness of m to 50 μm on an aluminum alloy. A head with reinforcing plates bonded to both sides that has been subjected to this process 5- shows almost no wear resistance even if it comes into contact with the tape 1 million times at a relative speed of 6W, and the level of damage to the media is also low. The amount was very small because the alumina outer membrane is porous.

Furthermore, a lubricant is sealed in the pores of this porous alumina layer. For example, MOB particles are added to epoxy resin.
3 (+ mt%) and apply it to the surface and lightly wrap the surface.Alternatively, by baking Teflon resin and embedding it in the hole, lubricity and wear resistance are further improved. It can be a part.

〔effect〕

The magnetic head according to the present invention has superior wear resistance and lubricity of the reinforcing plate itself compared to conventional heads using simple glass or ceramic for the reinforcing plate. At the same time, both effects of preventing damage to the media can be brought about.

6-

[Brief explanation of the drawing]

Figure 1 is a structural diagram of a laminate type magnetic head. 1. Metal magnetic material 2. Reinforcement plate that's all Applicant: Suwa Sayakosha Co., Ltd. Agent Patent Attorney Mogami 7- Li0-

Claims (1)

[Claims] (1) A magnetic head in which an aluminum reinforcing plate with a crystalline alumina layer formed on the surface is bonded to at least one side of a core made of a metal magnetic material. (2. A magnetic head according to claim 1, which uses an aluminum reinforcing plate in which a lubricant is sealed in a porous layer of crystalline alumina.