JPS59190264A - Ceramic composition for magnetic head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head for use as a structural part of a magnetic head. I
・This applies to porcelain compositions for magnetic heads used for sliders or spacers, which are essential for 111 construction.

Generally magnetic l\rad, lln -ZTI ferrite,
The core made of magnetic material of NL-Zη Noelai [~] and the II'1+ja parts made of non-magnetic material are assembled by glass melting, and especially for digital magnetic heads, magnetic material 1-C2, J-Gutta N with high frequency characteristics and rg wear resistance.

-Zη) High magnetic permeability Mn Zn ferrite+- is used in place of the upper layer 1~, and 1iO2BaO based porcelain having the same coefficient of thermal expansion is used for the non-magnetic structural component material Δ.

In other words, if the thermal expansion coefficients of the core material and the non-magnetic (4) structural product are different, distortion will occur when glass welding them together, resulting in deterioration of magnetic properties. This has caused a huge problem in the assembly of C1a.

In general, if there are many pores in this non-magnetic structural component material, when the magnetic head and the recording medium come into contact with each other, the magnetic powder coated on the recording medium may enter the pores or cause depping. To prevent damage to magnetic heads and recording media, a highly densified non-magnetic ceramic composition with low porosity is desired.

The conventional TL 02 Ba O based porcelain composition is based on BaO
It is known that the coefficient of thermal expansion increases linearly as the temperature increases, and the coefficient of thermal expansion of the Mn-Zη ferrite of the core 4A mentioned above is fixed by the composition determined by the required electromagnetic properties. 105・-115×
10-7/°C, it is necessary to match the thermal expansion coefficient of the non-magnetic structural component material layer to that of ferrite, and in order to suppress the difference in thermal expansion coefficient to 2xlO-7/°C or less, TL02
A porcelain composition having a composition of 50.'' 75 wt% and 25 to 50 wt% of BaO was used.On the other hand, as a method for reducing the porosity of a porcelain composition, a porcelain composition having the composition as described in -1- #203, 5LO2, MgO.

A method is known in which the sintering density is improved by adding at least one kind of sintering aid Δ such as SrO, CClO, ZrO2 at 4 wt% or more. %
pores remain, especially when the added amount of Zr02 is 2wt%
In the following cases, the dimensions of the molded object are 40mm x 20mm
When the size of the sintered body becomes 20 mm, the normal sintering method has a problem in that the inside of the sintered body is reduced and becomes -C black.

In addition, C1 hot isostatic pressing is a known method for reducing porosity, and although it is extremely effective, since this treatment is usually carried out in an argon atmosphere, the treated surface is reduced and becomes black. Even if heat treatment was performed again in an oxygen atmosphere, it was difficult to completely decolorize the color, and it was not possible to uniformly restore the color to the inside of the material.

In view of the above-mentioned problems, this invention has a coefficient of thermal expansion equivalent to Mn-Zη fiber ply 1, has a very dense crystal structure, and does not require hot isostatic pressing. 0.2, which is equivalent to hot isostatic pressing with normal sintering.
TL 02 Ba O
This paper proposes a ceramic composition based on the ceramic composition.

That is, this invention is T,02! ]0”□ 75w
t%, BaO25-50wt%, TL 02
, Zy 0210, taking the total of BaO as 100
・Contains 15wt% of Ba TL4, TL
It consists of three phases: O2゜Zy Tj 04, and has a porosity of 0.2
This is a ceramic composition for a magnetic head that has a high density of less than 1.

The porcelain composition according to the present invention includes Ba T1.40B,
TL 02.

It is characterized by being composed of three phases of Zr TL 04, and can be made denser to the same level as the porosity of hot isostatically pressed materials, and has a thermal expansion coefficient of 105-115x io.
It is possible to accurately adjust the temperature within the range of -7/°C.
Because it contains r02, it can be sintered at a lower temperature than the conventional sintering temperature J, so it is dense, has few pores, has no defects, has good wear resistance, and has a sufficiently small crystal grain size and good workability. .

The porcelain composition according to the invention (jruZy TL 0&
When the phase is observed using an It is thought that this will allow for the inflow of the sintered body, which will be very effective in preventing blackening inside the sintered body.

The reasons for limiting the components of the six-piece composition according to this invention are as follows.

In Ding Lo, BaO system, the thermal expansion coefficient is TL 025
(hv t% - (notification Daihaku 11! iX 10-' /°
Therefore, if TLO850 wL% (h)1 is contained, the thermal expansion coefficient will be less than 115 x 10-7/°C, but the transverse refraction η will be significantly lowered and T*02 will be 75 )
If the content exceeds v1%, the thermal expansion coefficient and 05
x 10-' / "C becomes a cylinder, Mn -Znn
Since it is unsuitable as a partner for Karasu Seifuku with Fushii 1~, the content is set at TL0□50□~75wt%.

BaO has a TL 02 tail related odor - U, [If the content of 3aO exceeds 50 wt%, the thermal expansion coefficient is 115X1
0-7/℃ or less, but the bending shear J decreases sharply and B
When the aO content is 25 wt% unvortexed, the coefficient of thermal expansion is
105xlO-7/'C) Dark roar, l"In Z
Since it is not compatible with any glass melting device, Ba025 to 50 wt% is contained.

Zy 02 changes the porosity of TL 02 Ba O system
It is added to stabilize the temperature, but its content is T
j 02 , the total of Ba O is 100, 10w
When t% is not swirled, the porosity of the sintered ceramic composition is 1.0% or more, and the structure is BaTL40g.

There are three phases of TiO2 and ZrO2, and the inside of the sintered body is easily reduced and becomes black, so there is no good J color. , also 1
If the content exceeds 5 wt%, the porosity of the sintered body will be 0.2% or more, and the workability will deteriorate, so it is considered unsuitable as a counterpart to Soft Ferrite 1. Therefore, 10-15 wt%
The addition of

The present invention will be explained below based on examples.

Using commercially available TLO2, BaCO3, and ZyOa, as shown in Table 1, the composition after sintering was the composition ratio according to the present invention (N: 1.1-6) and the composition ratio according to the present invention;
The balance Q"i Ll is adjusted so that the composition ratio outside the range (7 to 9) is obtained.
, mixed in a ball mill and dried in air for 900 min.
Calcination was performed for 12 hours. Further, the calcined raw material was again pulverized in a ball mill until the average particle size was 1.3°C, and then polyvinyl alcohol was added as a binder to 1.5°C.
Added 1Vt% and granulated it. After granulation, 2oook 4
The molded material was molded into a 40×20×2 Ontm brush cutter with a 1200″ C121+ sintering process in air.

Properties such as density, coefficient of thermal expansion, and hirakasu sand layer were investigated for the processed porcelain, and the measurement results are shown in Table 2. The power increase of the main axis morph is expressed in units of 1 and evaluated.

As is clear from Tables 1 and 2, trial No. 7.
9 Comparative Example The coefficient of thermal expansion of the bare body is the ratio -Zη plane] -Lye 1-
Heat t15 bulge coefficient 105・~11! ix 10-7
/ ``C, but the pore size is poor, whereas the embodiment of this invention (sample No. 1 -〇) has a thermal expansion coefficient of 105 to 115 x 10-7/''C. It exhibits outstanding properties such as mechanical strength and hardness, and is especially densified to the same degree as VJ slope treated with hot isostatic pressing, and has a small crystal grain size. Gentleness,
Because the porcelain has few holes and has good workability,
It can be seen that it has excellent wear resistance and is most suitable for magnetic head structural parts on which the recording medium slides. .

Figure 1 Below margin

Claims (1)

[Claims] 1 TLo+! 50. ~75wt%, BaO25-
A ceramic composition for a magnetic head, characterized in that the composition consists of 50wt% of Zr0210-15wt%, with the sum of h1 of Zr02 and BaO being 100, and the porosity is increased to 0.2% or less. .