JPH0581550B2 - - Google Patents
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- Publication number
- JPH0581550B2 JPH0581550B2 JP1106934A JP10693489A JPH0581550B2 JP H0581550 B2 JPH0581550 B2 JP H0581550B2 JP 1106934 A JP1106934 A JP 1106934A JP 10693489 A JP10693489 A JP 10693489A JP H0581550 B2 JPH0581550 B2 JP H0581550B2
- Authority
- JP
- Japan
- Prior art keywords
- thermal expansion
- mol
- magnetic
- composition
- expansion coefficient
- 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 - Lifetime
Links
- 239000000203 mixture Substances 0.000 claims description 28
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 10
- 239000000919 ceramic Substances 0.000 claims description 8
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 4
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 4
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 4
- 229910052573 porcelain Inorganic materials 0.000 description 16
- 229910000859 α-Fe Inorganic materials 0.000 description 13
- 239000013078 crystal Substances 0.000 description 8
- 239000000463 material Substances 0.000 description 7
- 230000007423 decrease Effects 0.000 description 5
- 239000000696 magnetic material Substances 0.000 description 5
- 239000011162 core material Substances 0.000 description 4
- 230000006866 deterioration Effects 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 238000001513 hot isostatic pressing Methods 0.000 description 3
- 238000003754 machining Methods 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 229910018605 Ni—Zn Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000002050 diffraction method Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 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
- 238000002156 mixing Methods 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N nickel(II) oxide Inorganic materials [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
- Magnetic Heads (AREA)
- Hard Magnetic Materials (AREA)
Description
【発明の詳細な説明】
利用産業分野
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、特にデジタル記録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
使用する熱膨張係数（α）が120×10-7／℃以上
であることを特徴とする磁気ヘツド用磁器組成物
に関する。
従来技術
一般にフエライト磁気ヘツドは、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、飽和磁束密度Bs＝
4500G程度で透磁率の高いMn−Znフエライト
（熱膨張係数α＝106×10-7／℃）が使用され、非
磁性構造部品材料には熱膨張係数が上記フエライ
トと同等のTiO2−CaO系磁器が使用されている。
最近、磁気ヘツド特性向上のため、さらに一段
と磁気特性のすぐれたBs＝5100G程度、硬度Hv
＝650以上のMn−Znフエライトが使用されるよ
うになつた。
しかしながら、前記の高性能Mn−Znフエライ
トは熱膨張係数（α）が120×10-7／℃以上であ
り、非磁性構造部品材料にかかるフエライトの熱
膨張係数（α）に合致する磁器組成物が要望され
てきた。
すなわち、コア材と、非磁性構造部品との熱膨
張係数が異なると、これらをガラス溶着する際
に、フエライトコアに応力が掛り、磁気特性の劣
化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、大きな問題となるため、磁性
材料と非磁性材料の熱膨張係数が一致するよう材
料組成が選択されている。
また、この非磁性構造部品材料に、結晶の脱落
とかマイクロクラツクが多く存在すると、磁気ヘ
ツドと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粉が上記欠陥に付着した
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、かかる欠陥が機械加工時に発生し
易い材料であつてはならない。
発明の目的
この発明は、前記問題点解決のため、熱膨張係
数α＝120×10-7／℃以上、硬度Hv＝650程度の
高性能Mn−Znフエライオと同等の熱膨張係数を
有し、結晶組織の微細且つ緻密で、機械加工時に
マイクロクラツク、あるいは結晶の脱落の極めて
少ない磁器組成物の提供を目的としている。
発明の概要
発明者は、熱膨張係数α＝120×10-7／℃以上
を有し、硬度Hv＝650の高性能Mn−Znフエライ
トと同等以上の熱膨張係数を有し、結晶組織の微
細且つ緻密で機械加工時にマイクロクラツク、あ
るいは結晶の脱落の極めて少ない磁器組成物につ
いて、種々検討した結果、磁器組成物の熱膨張係
数はその結晶構造に左右され、NaCl型の構造を
もつNiO、MgO、TIO2等は50〜500℃での熱膨
張係数が125〜140×10-7／℃という大きな値を有
し、かつ緻密で硬度等諸特性が磁気ヘツド用磁器
組成物として適した値をもつことに着目し、特に
NaCl型構造相をもつセラミツクスとして、特定
の組成のNiO−MgO−TiO2系がその目的に適す
ることを知見した。
すなわち、この発明は、
NiO50〜90モル％、MgO10〜40モル％、
TiO210〜20モル％からなり、熱膨張係数α＝120
×10-7℃以上で、硬度Hv＝700以上の結晶組織の
微細且つ緻密な磁器組成物であり、さらに、
前記磁器組成物に、NiO、MgO、TiO2の合計
量100に対してAl2O3、Fe2O3、ZnO、MnO、
SiO2の少なくとも１種を5wt％以下含有した、熱
膨張係数α＝120×10-7／℃以上、硬度Hv＝700
以上の結晶組織の微細且つ緻密な磁器組成物であ
る。
発明の構成と効果
この発明による特定の組成を有する
NiO−MgO−TiO2系セラミツクスは、NaCl型
構造を有する固溶体、（Nix・Mg1-x）Ｏ及び
（Niy・Mg1-y）TiO3の２相からなることはＸ
線回折法により確認され、この相中の（Nix・
Mg1-x）Ｏの存在が、NiO、MgO、TiO2系セラ
ミツクスの熱膨張係数を高めることに寄与し、
また、（Niy・Mg1-y）TiO3が混在することに
より、このセラミツクスが緻密化することが分つ
た。
この発明の磁器組成物の熱膨張係数αが120〜
130×10-7／℃となり、前述したBs＝5100G程度、
硬度Hv＝650の高性能Mn−Znフエライトの熱膨
張係数に合致するため、ガラス溶着の際の応力の
負荷がなく、磁気特性の劣化が生せず、ひび、剥
離等の問題も招来することなく、また、この発明
による磁器組成物の硬度Hvが700〜1000となり、
Mn−Znフエライトコアの硬度に近似するため、
磁器ヘツドの摺動面に段差を生じない利点があ
る。
組成の限定理由
この発明による磁器組成物の組成を限定した理
由を以下に説明する。
NiOが50モル％未満では、熱膨張係数αが120
×10-7／℃未満に低下して、目的とする磁気ヘツ
ド用としては好ましくなく、また、90モル％を超
えると、磁器組成物内に気孔が増加して、耐摩耗
性が低下し、また、加工性も劣化するので好まし
くない。
また、MgOが10モル％未満では、緻密な磁器
組成物が得られず好ましくなく、40モル％を超え
ると、熱膨張係数が120×10-7／℃未満に低下す
るので好ましくない。
TiO2が10モル％未満では、磁器組成物内に気
孔が増加して、耐摩耗性、加工性の劣化を招来
し、20モル％を超えると、熱膨張係数が120×
10-7℃未満に低下し、磁気ヘツド用としては好ま
しくないので、NiO50〜90モル％、MgO10〜40
モル％、TiO210〜20モル％の組成に限定する。
また、添加物のAl2O3、Fe2O3、ZnO、MnO、
SiO2は磁器組成物の緻密化に効果があるが、そ
の添加量が5wt％を超えると、緻密化の効果が飽
和し、特にAl2O3の場合、熱膨張係数αが120×
10-7／℃未満に低下するので好ましくない。
実施例
市販されているNiO、MgO、TiO2、Al2O3、
Fe2O3、ZnO、MnO、SiO2を用いて、第１表に
示す如く、熱間静水圧プレス処理後の組成がこの
発明による組成（No.１〜９）、及びこの発明の範
囲外の組成（No.10〜12）となるように、秤量し、
ボールミルで６時間混合し、乾燥した後、仮焼、
微粉砕、造粒後に１・5T／cm2の成形圧で28mm×
28mm×15mm寸法に成形し、第１表に表した焼結条
件、及びHIP（熱間静水圧プレス）条件で磁器組
成物を製造した。
得られた磁器について、その密度、気孔率、熱
膨張係数、ビツカース硬度の各特性を調べ、その
結果を第１表に表す。
【表】[Detailed Description of the Invention] Field of Application This invention relates to non-magnetic materials used for structural parts of magnetic heads, and particularly for sliders or spacers essential to the construction of various magnetic heads such as computers, especially ferrite magnetic heads for digital recording. The present invention relates to a ceramic composition for a magnetic head, characterized in that the coefficient of thermal expansion (α) used is 120×10 -7 /°C or more. Prior Art Ferrite magnetic heads are generally assembled by glass welding a core made of magnetic materials such as Mn-Zn ferrite or Ni-Zn ferrite and structural parts made of non-magnetic materials. As a material, saturation magnetic flux density Bs=
Mn-Zn ferrite (thermal expansion coefficient α = 106 × 10 -7 /℃), which has a high magnetic permeability of about 4500G, is used, and TiO 2 -CaO-based material with a thermal expansion coefficient equivalent to that of the above ferrite is used as the non-magnetic structural component material. Porcelain is used. Recently, in order to improve the magnetic head characteristics, the magnetic characteristics are even better, Bs=5100G, hardness Hv.
=650 or higher Mn-Zn ferrites have come to be used. However, the above-mentioned high-performance Mn-Zn ferrite has a thermal expansion coefficient (α) of 120 × 10 -7 /℃ or more, and the porcelain composition matches the thermal expansion coefficient (α) of ferrite for non-magnetic structural component materials. has been requested. In other words, if the thermal expansion coefficients of the core material and non-magnetic structural parts are different, stress will be applied to the ferrite core when they are welded to glass, which will not only cause deterioration of magnetic properties but also cause cracks, peeling, etc. Since this poses a major problem in assembling the magnetic head, the material composition is selected so that the coefficients of thermal expansion of the magnetic material and the non-magnetic material match. In addition, if there are many falling crystals or microcracks 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 adhere to the defects or cause chipping. The material must not be susceptible to such defects during machining, since this may damage the magnetic head or recording medium. Purpose of the Invention In order to solve the above problems, the present invention has a thermal expansion coefficient α = 120 × 10 -7 / °C or more and a hardness Hv = about 650, which is equivalent to a high-performance Mn-Zn ferrite. The object of the present invention is to provide a porcelain composition that has a fine and dense crystal structure and that causes very few microcracks or crystals to fall off during machining. Summary of the Invention The inventor has discovered that the invention has a thermal expansion coefficient α = 120 x 10 -7 /°C or higher, a thermal expansion coefficient equal to or higher than that of high-performance Mn-Zn ferrite with a hardness Hv = 650, and a fine crystal structure. As a result of various studies on porcelain compositions that are dense and have very few microcracks or crystals falling off during machining, we found that the thermal expansion coefficient of porcelain compositions depends on their crystal structure. MgO, TIO 2 , etc. have large thermal expansion coefficients of 125 to 140 x 10 -7 /°C at 50 to 500°C, and have properties such as denseness and hardness that are suitable for use as ceramic compositions for magnetic heads. Focusing on having
We found that the NiO-MgO-TiO 2 system with a specific composition is suitable for this purpose as a ceramic with a NaCl-type structural phase. That is, in this invention, NiO 50 to 90 mol%, MgO 10 to 40 mol%,
Consisting of 10-20 mol% TiO 2 , thermal expansion coefficient α = 120
×10 -7 ℃ or more, it is a fine and dense porcelain composition with a crystal structure of hardness Hv = 700 or more, and furthermore, Al 2 is added to the porcelain composition with respect to the total amount of NiO, MgO, and TiO 2 per 100. O3 , Fe2O3 , ZnO , MnO,
Contains at least one type of SiO 2 at 5wt% or less, thermal expansion coefficient α = 120 × 10 -7 / °C or more, hardness Hv = 700
This is a porcelain composition with a fine and dense crystal structure as described above. Structure and Effects of the Invention The NiO-MgO-TiO 2 ceramics having a specific composition according to the present invention is a solid solution having a NaCl type structure, (Ni x Mg 1-x )O and (Ni y Mg 1-y ). The fact that it consists of two phases of TiO 3 is
Confirmed by line diffraction method, (Ni x・
The presence of Mg 1-x ) O contributes to increasing the thermal expansion coefficient of NiO, MgO, and TiO 2 ceramics, and the presence of (Ni y Mg 1-y ) TiO 3 increases the was found to become denser. The thermal expansion coefficient α of the porcelain composition of this invention is 120~
130×10 -7 /℃, and the aforementioned Bs = about 5100G,
Since it matches the thermal expansion coefficient of high-performance Mn-Zn ferrite with hardness Hv = 650, there is no stress load during glass welding, and there is no deterioration of magnetic properties, which would otherwise cause problems such as cracking and peeling. Moreover, the hardness of the porcelain composition according to the present invention is 700 to 1000,
To approximate the hardness of Mn−Zn ferrite core,
This has the advantage that there are no steps on the sliding surface of the porcelain head. Reasons for limiting the composition The reasons for limiting the composition of the ceramic composition according to the present invention will be explained below. When NiO is less than 50 mol%, the thermal expansion coefficient α is 120
If it decreases to less than ×10 -7 /°C, it is not suitable for the intended magnetic head, and if it exceeds 90 mol%, pores increase in the porcelain composition, resulting in a decrease in wear resistance. In addition, processability is also deteriorated, which is not preferable. Furthermore, if MgO is less than 10 mol%, a dense ceramic composition cannot be obtained, which is not preferable, and if it exceeds 40 mol%, the thermal expansion coefficient decreases to less than 120×10 -7 /°C, which is not preferable. If TiO 2 is less than 10 mol%, pores will increase in the porcelain composition, resulting in deterioration of wear resistance and workability, and if it exceeds 20 mol%, the thermal expansion coefficient will be 120 ×
Since the temperature decreases to below 10 -7 ° C and is not suitable for magnetic heads, 50 to 90 mol% NiO and 10 to 40 mol% MgO are used.
mol%, limited to a composition of 10 to 20 mol% TiO2 . In addition, additives such as Al 2 O 3 , Fe 2 O 3 , ZnO, MnO,
SiO 2 is effective in densifying porcelain compositions, but when the amount added exceeds 5wt%, the densification effect is saturated, and especially in the case of Al 2 O 3 , the thermal expansion coefficient α is 120×
It is not preferable because it decreases to less than 10 -7 /°C. Examples Commercially available NiO, MgO, TiO 2 , Al 2 O 3 ,
Using Fe 2 O 3 , ZnO, MnO, and SiO 2 , as shown in Table 1, the composition after hot isostatic pressing is the composition according to the present invention (Nos. 1 to 9) and outside the scope of the present invention. Weigh it so that it has the composition (No. 10 to 12),
After mixing in a ball mill for 6 hours and drying, calcining,
After fine pulverization and granulation, the molding pressure of 1.5T/ cm2 is 28mm
A porcelain composition was produced by molding it into a size of 28 mm x 15 mm under the sintering conditions and HIP (hot isostatic pressing) conditions shown in Table 1. The obtained porcelain was examined for its density, porosity, coefficient of thermal expansion, and Vickers hardness, and the results are shown in Table 1. 【table】
Claims (1)
が120×10-7／℃以上であることを特徴とする磁
気ヘツド用磁気組成物。 ２ NiO50〜90モル％、MgO10〜40モル％、 TiO210〜20モル％からなり、NiO、MgO、
TiO2の合計量100に対して、Al2O3、Fe2O3、
ZnO、MnO、SiO2の少なくとも１種を5wt％以
下含有し、熱膨張係数（α）が120×10-7／℃以
上であることを特徴とする磁気ヘツド用磁器組成
物。[Claims] 1 Consists of 50 to 90 mol% NiO, 10 to 40 mol% MgO, and 10 to 20 mol% TiO 2 , and has a coefficient of thermal expansion (α)
1. A magnetic composition for a magnetic head, characterized in that the temperature is 120×10 -7 /°C or more. 2 Consisting of 50-90 mol% NiO, 10-40 mol% MgO, 10-20 mol% TiO2 , NiO, MgO,
For the total amount of TiO 2 of 100, Al 2 O 3 , Fe 2 O 3 ,
A ceramic composition for a magnetic head, which contains at least 5 wt% of at least one of ZnO, MnO, and SiO 2 and has a coefficient of thermal expansion (α) of 120×10 -7 /°C or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1106934A JPH02283654A (en) | 1989-04-25 | 1989-04-25 | Ceramic composition for magnetic head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1106934A JPH02283654A (en) | 1989-04-25 | 1989-04-25 | Ceramic composition for magnetic head |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02283654A JPH02283654A (en) | 1990-11-21 |
| JPH0581550B2 true JPH0581550B2 (en) | 1993-11-15 |
Family
ID=14446229
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1106934A Granted JPH02283654A (en) | 1989-04-25 | 1989-04-25 | Ceramic composition for magnetic head |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02283654A (en) |
-
1989
- 1989-04-25 JP JP1106934A patent/JPH02283654A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02283654A (en) | 1990-11-21 |
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