JPS643828B2 - - Google Patents
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- Publication number
- JPS643828B2 JPS643828B2 JP58206707A JP20670783A JPS643828B2 JP S643828 B2 JPS643828 B2 JP S643828B2 JP 58206707 A JP58206707 A JP 58206707A JP 20670783 A JP20670783 A JP 20670783A JP S643828 B2 JPS643828 B2 JP S643828B2
- Authority
- JP
- Japan
- Prior art keywords
- tio
- mgo
- magnetic
- cao
- thermal expansion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- 239000000203 mixture Substances 0.000 claims description 27
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 25
- 229910015902 Bi 2 O 3 Inorganic materials 0.000 claims description 6
- 239000000919 ceramic Substances 0.000 claims description 6
- 229910052747 lanthanoid Inorganic materials 0.000 claims description 4
- 150000002602 lanthanoids Chemical class 0.000 claims description 4
- 230000003647 oxidation Effects 0.000 claims description 3
- 238000007254 oxidation reaction Methods 0.000 claims description 3
- 229910000311 lanthanide oxide Inorganic materials 0.000 claims 1
- 229910000859 α-Fe Inorganic materials 0.000 description 15
- 229910052573 porcelain Inorganic materials 0.000 description 13
- 239000011521 glass Substances 0.000 description 12
- 239000000463 material Substances 0.000 description 10
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 6
- 239000013078 crystal Substances 0.000 description 6
- 238000003466 welding Methods 0.000 description 5
- 238000005245 sintering Methods 0.000 description 4
- 239000011162 core material Substances 0.000 description 3
- 239000000696 magnetic material Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 229910001035 Soft ferrite Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- 239000006247 magnetic powder Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
- Magnetic Heads (AREA)
Description
この発明は、磁気ヘツドの構造部品に用いる非
磁性材料に係り、コンピユータ等の各種磁気ヘツ
ド、特にフロツピーデイスク用フエライト磁気ヘ
ツドの構成に不可欠のスライダーあるいはスペー
サーに使用する磁気ヘツド用磁器組成物に関す
る。
一般に磁気ヘツドは、Mn―Znフエライト，Ni
―Znフエライトの磁性材料からなるコアと非磁
性材料からなる構造部品とをガラス溶着して組立
てられており、特にデジタル用磁気ヘツドには磁
性材料として、高周波特性及び耐摩耗性のすぐれ
たNi―Znフエライトに変えて高透磁率のMn―
Znフエライトが使用され、非磁性構造部品材料
には熱膨張係数が同等のTiO2―BaOまたはTiO2
―CaO系磁器が使用されている。
すなわち、コア材と、非磁性構造部品との熱膨
脹係数が異なると、これらをガラス溶着する際
に、歪を生じ、磁気特性の劣下が起こるだけでな
く、ひび、剥離等を生じて磁気ヘツドの組立上大
きな問題となつている。
さらに、この非磁性構造部品材料に気孔が多く
存在すると、磁気ヘツド記録媒体との接触走行時
に、記録媒体にコーテイングされた磁性紛が上記
気孔に付着したり、チツピングを生じて磁気ヘツ
ドや記録媒体を損傷するため、無孔で高密度な非
磁性磁器組成物が切望されている。
従来のTiO2―BaOまたはTiO2―CaO系磁器組
成物は、BaOまたはCaOの量とともに熱膨張係
数が直線的に大きくなることが知られており、上
述したコア材のMn―Znフエライトの熱膨張係数
は要求される電磁気特性によつて定まる組成によ
り固定されるが、90〜120×10-7／℃であるため、
非磁性構造部品材料の熱膨張係数をフエライトの
方に合せる必要があり、熱膨張係数の差を２×
10-7／℃以下に抑えるべく、TiO2 50〜75wt％、
CaO 25〜50wt％またはTiO2 77〜86wt％、
CaO14〜23wt％の組成からなる磁気組成物が使
用されていた。
しかしながら、従来の磁気組成物は、その焼結
品は難加工性であり、そのため量産に際して加工
機を特殊なものとするなど種々の問題があつた。
また、従来の磁器組成物は、溶着ガラスとのなじ
みが悪く、ガラス中に気泡を生じ易いという問題
があつた。
そこで、本発明者らは、従来の磁器組成物の欠
点を除き、Mn―Znフエライトと同等の熱膨張係
数を有し、結晶組織が非常に緻密でかつすぐれた
加工性を有し、溶着ガラスとのなじみも良好な磁
気ヘツド用磁器組成物として、TiO2―MgO，
TiO2―MgO―CaO系磁器組成物を提案した（特
願昭58―125000号）。
しかしながら、上記の磁器組成物は、気孔率が
0.20〜0.30％程度あるため、磁気ヘツドの高密度
記録化に対処したり、スライダー材料としての精
密加工を施す必要から、気孔率の低減並びに加工
性の向上が不可欠であつた。
この発明は、TiO2―MgO，TiO2―MgO―
CaO系磁気組成物の改良を目的とし、Mn―Znフ
エライトと同等の熱膨張係数を有し、結晶組織が
非常に緻密で気孔率が極めて小さく、かつ精密加
工性にすぐれ、溶着ガラスとの馴染みも良好なる
磁気ヘツド用磁気組成物を提案するものである。
すなわち、この発明は、
TiO2 10wt％〜90wt％、
MgO 10wt％〜90wt％からなり、
TiO2，MgOの合計を100wt％として、
Bi2O3，Y2O3，RO（ランタニド系の酸化物）の
うち少なくとも１種を5wt％以下含有し、熱膨張
係数90×10-7／℃〜120×10-7／℃を有すること
を要旨とする磁気ヘツド用磁気組成物であり、さ
らに、
TiO2 10wt％〜90wt％、
MgO 10wt％〜90wt％からなり、
TiO2，MgOの合計を100wt％として、
CaO 25wt％以下に、
Bi2O3，Y2O3，RO（ランタニド等の酸化物）の
うち少なくとも１種を5wt％以下含有し、熱膨張
係数90×10-7／℃〜120×10-7／℃を有すること
を要旨とする磁気ヘツド用磁器組成物である。
この発明による磁器組成物は、熱膨脹係数を90
〜120×10-7／℃の範囲に精度よく調整すること
ができ、溶着ガラスとの馴染みにすぐれ、該ガラ
ス内に気泡がほとんど発生せず、気孔率が極めて
小さく、すぐれた加工性を有し量産性にすぐれて
いる特徴がある。
この発明による磁器組成物の成分を限定した理
由は以下のとおりである。
TiO2―MgO系において、TiO2 10wt％未満、
MgO 90wt％を越える含有では、熱膨張係数が
120×10-7／℃を越えてしまい、Mn―Znフエラ
イトとのガラス溶着の相手材料として不適であ
り、また、焼結が困難となる。一方、TiO2が
90wt％を超え、MgO 10wt％未満の含有である
と、熱膨張係数が90×10-7／℃未満となり、Mn
―Znフエライトのガラス溶着の相手材料として
不適であり、また、焼結が困難となるので、Mn
―Znフエライトの熱膨張係数90〜120×10-7／℃
と同じ熱膨張係数を保持させて焼結性を良好とす
るため、TiO2 10wt％〜90wt％、MgO 10wt％
〜90wt％の含有とする。特に、熱膨張係数が、
105×10-7／℃程度のMn―Znフエライトと適合
する磁器組成物としては、TiO2 38wt％、MgO
62wt％の組成のものが最適である。
この発明の特徴であり、気孔率を低減するため
の添加物であるBi2O3，Y2O3，RO（ランタニド系
の酸化物）は、これらのうち少なくとも１種を含
有するが、その含有がTiO2，MgOの合計を
100wt％として、5wt％を超える含有では、焼結
の際に、液相が多量に生成し、粒成長を促進し、
焼結後の磁器は粗大な結晶粒子を有する組織とな
り、気孔率が増大させるため、5wt％以下の含有
とする。
CaOは、TiO2―MgO系の焼結性を改善し、磁
器を高密度化するために添加するものであるが、
その含有がTiO2，CaOの合計を100wt％として、
25wt％を超える含有では、フエライトコアと溶
着するガラス内にCaOが溶出してCaO―SiO2系
の結晶が成長し、ガラス溶着後の加工面に残留す
る粗大化結晶は記録媒体の摺動時に、該結晶を脱
落させる懸念があると共に材料の強度も低くな
り、ソフトフエライトの相手材料として不適とな
るため、CaOは25wt％以下の添加とする。また、
CaOを含有したこの発明の三元系組成物では、前
記Mn―Znフエライトと適合するものは、例え
ば、CaO 2wt％、MgO 55wt％、TiO2 45wt％
のものが好ましい。
以下に、この発明を実施例に基づいて説明す
る。
市販されているTiO2，MgO，CaO，Bi2O3，
Y2O3，ROを用いて、第１表に示す如く、焼結後
の組成がこの発明による組成化（No.１〜10）なら
びにこの発明の範囲外及び従来の磁器組成物の組
成化（No.11〜15）となるよう秤量し、ボールミル
で混合し、乾燥した後、空気中で900℃、２時間
の仮焼を行つた。さらに仮焼した原料を再びボー
ルミルで平均粒度1.3μm程度になるまで、微粉砕
し、次に結合剤としてポリビニルアルコールを
1.5wt％加えて造粒した。造粒後に、2000Kg／cm2
の成形圧で40×20×20mmの寸法に成形し、第１表
の試料No.３〜５，９〜10，11〜13は空気中で1280
℃，２時間、他試料は空気中で1260℃，２時間の
焼結を行つた。
得られた磁器について、密度、熱膨張係数、ビ
ツカース硬度等の特性を調べ、第２表に測定結果
を示している。また、表中の加工性は、同一の加
工機を使用しその主軸モータの電力増加量をワツ
ト単位で表わし評価している。
第１表，第２表から明らかな如く、試料No.11〜
13の比較例はその熱膨張係数がMn―Znフエライ
トの熱膨張係数90〜120×10-7／℃に合致せず、
また、試料工性が悪く、比較例の試料No.14，15は
気孔率が高いのに対し、この発明の実施例（試料
No.１〜10）は、気孔率が0.20％未満と低く、かつ
熱膨張係数を90〜120×10-7／℃の間にコントロ
ールすることができ、機械的強度，加工性等もす
ぐれた特性を示しており、耐摩耗性にすぐれ、記
録媒体が摺動する磁気ヘツド構造部品用材料に最
適であることがわかる。
The present invention relates to non-magnetic materials used for structural parts of magnetic heads, and more particularly to a ceramic composition for magnetic heads used for sliders or spacers essential to the construction of various magnetic heads such as computers, particularly ferrite magnetic heads for floppy disks. . Generally, magnetic heads are made of Mn-Zn ferrite, Ni
-A core made of Zn ferrite magnetic material and structural parts made of non-magnetic material are assembled by glass welding.Ni- High permeability Mn instead of Zn ferrite
Zn ferrite is used, and the non-magnetic structural component material is TiO 2 - BaO or TiO 2 with an equivalent coefficient of thermal expansion.
-CaO-based porcelain is used. In other words, if the thermal expansion coefficients of the core material and the non-magnetic structural parts differ, distortion will occur when they are welded to glass, which will not only cause deterioration of magnetic properties but also cause cracks, peeling, etc., and damage the magnetic head. This has become a major problem in assembly. Furthermore, if there are many pores in this non-magnetic structural component material, when the magnetic head runs in contact with the recording medium, the magnetic powder coated on the recording medium may adhere to the pores or cause chipping, causing the magnetic head or the recording medium to Therefore, a non-porous, high-density non-magnetic porcelain composition is desired. It is known that the thermal expansion coefficient of conventional TiO 2 -BaO or TiO 2 -CaO-based porcelain compositions increases linearly with the amount of BaO or CaO, and The expansion coefficient is fixed by the composition determined by the required electromagnetic properties, but since it is 90 to 120 × 10 -7 /℃,
It is necessary to match the thermal expansion coefficient of the non-magnetic structural component material to that of ferrite, and the difference in thermal expansion coefficient is 2×
In order to keep it below 10 -7 /℃, TiO 2 50-75wt%,
CaO 25-50wt% or TiO2 77-86wt%,
Magnetic compositions with compositions of 14-23 wt% CaO were used. However, the sintered products of conventional magnetic compositions are difficult to process, and as a result, there have been various problems such as the need for special processing machines for mass production.
Further, conventional porcelain compositions have a problem of poor compatibility with fused glass and the tendency to form bubbles in the glass. Therefore, the present inventors have removed the drawbacks of conventional porcelain compositions, have a coefficient of thermal expansion equivalent to that of Mn-Zn ferrite, have a very dense crystal structure and excellent workability, and have developed a method for welding glass. As a ceramic composition for magnetic heads that has good compatibility with TiO 2 -MgO,
A TiO 2 -MgO-CaO based ceramic composition was proposed (Patent Application No. 125000/1982). However, the above porcelain composition has a porosity of
Since the content is approximately 0.20 to 0.30%, it has been essential to reduce the porosity and improve processability in order to cope with higher density recording in magnetic heads and to perform precision processing as a slider material. This invention provides TiO 2 -MgO, TiO 2 -MgO-
Aiming to improve CaO-based magnetic compositions, it has a thermal expansion coefficient equivalent to Mn-Zn ferrite, has a very dense crystal structure, extremely low porosity, has excellent precision machinability, and is compatible with welded glass. The present invention also proposes a magnetic composition for a magnetic head that has excellent properties. That is, this invention consists of 10wt% to 90wt% of TiO 2 and 10wt% to 90wt% of MgO, with the total of TiO 2 and MgO being 100wt%, and Bi 2 O 3 , Y 2 O 3 , RO (lanthanide oxidation). A magnetic composition for a magnetic head, comprising 5 wt% or less of at least one of the following: It consists of TiO 2 10wt% to 90wt%, MgO 10wt% to 90wt%, and the total of TiO 2 and MgO is 100wt%, CaO is 25wt% or less, Bi 2 O 3 , Y 2 O 3 , RO (oxidation of lanthanides, etc.) This is a porcelain composition for a magnetic head, which contains 5 wt % or less of at least one of the following : The porcelain composition according to this invention has a coefficient of thermal expansion of 90
It can be precisely adjusted within the range of ~120×10 -7 /℃, has excellent compatibility with the welded glass, almost no air bubbles are generated in the glass, has extremely low porosity, and has excellent workability. It has the characteristic of being excellent in mass production. The reasons for limiting the components of the porcelain composition according to the present invention are as follows. In TiO 2 -MgO system, TiO 2 less than 10wt%,
If the MgO content exceeds 90wt%, the coefficient of thermal expansion will decrease.
It exceeds 120×10 -7 /°C, making it unsuitable as a partner material for glass welding with Mn--Zn ferrite, and making sintering difficult. On the other hand, TiO2
If the content exceeds 90wt% and MgO content is less than 10wt%, the thermal expansion coefficient will be less than 90×10 -7 /°C, and MgO
-Mn is not suitable as a partner material for glass welding of Zn ferrite, and it is difficult to sinter.
-Thermal expansion coefficient of Zn ferrite 90 to 120×10 -7 /℃
In order to maintain the same thermal expansion coefficient and improve sinterability, TiO 2 10wt% to 90wt% and MgO 10wt%
The content should be ~90wt%. In particular, the coefficient of thermal expansion is
Ceramic compositions compatible with Mn-Zn ferrite of about 105×10 -7 /℃ include TiO 2 38wt%, MgO
A composition of 62wt% is optimal. Bi 2 O 3 , Y 2 O 3 , RO (lanthanide-based oxides), which are the characteristics of this invention and are additives for reducing porosity, contain at least one of these. The content is the total of TiO 2 and MgO.
If the content exceeds 5wt% (100wt%), a large amount of liquid phase will be generated during sintering, promoting grain growth,
After sintering, the porcelain will have a structure with coarse crystal grains, increasing the porosity, so the content should be 5 wt% or less. CaO is added to improve the sinterability of the TiO 2 -MgO system and make the porcelain more dense.
The total content of TiO 2 and CaO is 100wt%,
If the content exceeds 25wt%, CaO will be eluted into the glass welded to the ferrite core, and CaO- SiO2 crystals will grow, and the coarse crystals remaining on the processed surface after glass welding will grow when the recording medium slides. , there is a concern that the crystals may fall off, and the strength of the material decreases, making it unsuitable as a partner material for soft ferrite, so CaO is added in an amount of 25 wt% or less. Also,
In the ternary composition of the present invention containing CaO, those compatible with the Mn--Zn ferrite include, for example, 2wt% CaO, 55wt% MgO, and 45wt% TiO2 .
Preferably. The present invention will be explained below based on examples. Commercially available TiO 2 , MgO, CaO, Bi 2 O 3 ,
Using Y 2 O 3 , RO, as shown in Table 1, the composition after sintering is the composition according to the present invention (No. 1 to 10) and the composition of the conventional porcelain composition outside the scope of the present invention. (Nos. 11 to 15), mixed in a ball mill, dried, and then calcined in air at 900°C for 2 hours. Furthermore, the calcined raw material is finely ground again in a ball mill until the average particle size is about 1.3μm, and then polyvinyl alcohol is added as a binder.
It was granulated by adding 1.5wt%. After granulation, 2000Kg/cm 2
Samples Nos. 3 to 5, 9 to 10, and 11 to 13 in Table 1 were molded to a size of 40 x 20 x 20 mm at a molding pressure of 1280 mm in air.
℃ for 2 hours, and other samples were sintered in air at 1260℃ for 2 hours. The obtained porcelain was examined for properties such as density, coefficient of thermal expansion, and Vickers hardness, and the measurement results are shown in Table 2. Furthermore, the workability in the table is evaluated by using the same processing machine and expressing the increase in power of the spindle motor in watts. As is clear from Tables 1 and 2, sample No. 11~
The thermal expansion coefficient of Comparative Example 13 did not match the thermal expansion coefficient of Mn-Zn ferrite, 90 to 120 × 10 -7 /℃,
In addition, sample workability was poor, and sample Nos. 14 and 15 of the comparative example had high porosity, whereas the example of the present invention (sample
Nos. 1 to 10) have a low porosity of less than 0.20%, can control the thermal expansion coefficient between 90 and 120×10 -7 /℃, and have excellent mechanical strength and workability. It can be seen that this material has excellent wear resistance and is ideal as a material for magnetic head structural parts on which the recording medium slides.
【表】【table】
【表】【table】
Claims (1)
うち少なくとも１種を5wt％以下含有し、熱膨張
係数90×10-7／℃〜120×10-7／℃を有すること
を特徴とする磁気ヘツド用磁器組成物。 ２ TiO210wt％〜90wt％、 MgO10wt％〜90wt％からなり、 TiO2、MgOの合計を100wt％として、 CaO25wt％以下に、 Bi2O3、Y2O3、RO（ランタニド系の酸化物）の
うち少なくとも１種を5wt％以下含有し、熱膨張
係数90×10-7／℃〜120×10-7／℃を有すること
を特徴とする磁気ヘツド用磁器組成物。[Claims] 1 Consisting of 10wt% to 90wt% of TiO 2 and 10wt% to 90wt% of MgO, with the total of TiO 2 and MgO being 100wt%, Bi 2 O 3 , Y 2 O 3 , RO (lanthanide oxidation 1. A ceramic composition for a magnetic head, comprising 5 wt% or less of at least one of the following : 2 Consisting of 10wt% to 90wt% of TiO 2 and 10wt% to 90wt% of MgO, with the total of TiO 2 and MgO being 100wt%, CaO of 25wt% or less, Bi 2 O 3 , Y 2 O 3 , RO (lanthanide oxide) 1. A ceramic composition for a magnetic head, comprising 5 wt% or less of at least one of the following :
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58206707A JPS60103076A (en) | 1983-11-02 | 1983-11-02 | Ceramic composition for magnetic head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58206707A JPS60103076A (en) | 1983-11-02 | 1983-11-02 | Ceramic composition for magnetic head |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60103076A JPS60103076A (en) | 1985-06-07 |
| JPS643828B2 true JPS643828B2 (en) | 1989-01-23 |
Family
ID=16527781
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58206707A Granted JPS60103076A (en) | 1983-11-02 | 1983-11-02 | Ceramic composition for magnetic head |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60103076A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3604739A1 (en) * | 1986-02-14 | 1987-08-20 | Wacker Chemitronic | MULTI-BLADE INTERNAL HOLE SAW FOR THE SAWING OF CRYSTAL RODS AND BY MEANS OF THIS SAW SEPARATION METHOD |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58139322A (en) * | 1982-02-10 | 1983-08-18 | Matsushita Electric Ind Co Ltd | Porcelain composition used for magnetic head fastener |
-
1983
- 1983-11-02 JP JP58206707A patent/JPS60103076A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60103076A (en) | 1985-06-07 |
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