JPH0228538B2 - - Google Patents
Info
- Publication number
- JPH0228538B2 JPH0228538B2 JP60122033A JP12203385A JPH0228538B2 JP H0228538 B2 JPH0228538 B2 JP H0228538B2 JP 60122033 A JP60122033 A JP 60122033A JP 12203385 A JP12203385 A JP 12203385A JP H0228538 B2 JPH0228538 B2 JP H0228538B2
- Authority
- JP
- Japan
- Prior art keywords
- coefficient
- mol
- thermal expansion
- magnetic
- ferrite
- 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 32
- 239000000919 ceramic Substances 0.000 claims description 13
- 239000012535 impurity Substances 0.000 claims description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 17
- 239000011162 core material Substances 0.000 description 11
- 229910052573 porcelain Inorganic materials 0.000 description 10
- 239000011521 glass Substances 0.000 description 8
- 239000000696 magnetic material Substances 0.000 description 6
- 238000005245 sintering Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 125000006850 spacer group Chemical group 0.000 description 4
- 229910010413 TiO 2 Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 230000009257 reactivity Effects 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- -1 MgO Chemical class 0.000 description 1
- 229910018605 Ni—Zn Inorganic materials 0.000 description 1
- 229910006404 SnO 2 Inorganic materials 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 238000005467 ceramic manufacturing process Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 239000006247 magnetic powder Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 1
- 238000004663 powder metallurgy Methods 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 229910001404 rare earth metal oxide Inorganic materials 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
- 229910001928 zirconium oxide Inorganic materials 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
- Magnetic Heads (AREA)
Description
産業上の利用分野
この発明は、構造部品特に磁気ヘツド用構造部
品に用いられる非磁性磁器組成物に係り、コア材
のフエライトの熱膨張係数と合致するように、組
成を変えて熱膨張係数を調整することができ、高
密度で摩耗係数が小さく、溶着ガラスとの反応性
が少ない磁気ヘツド用非磁性磁器組成物に関す
る。
従来の技術
一般に、構造部品として用いられる非磁性磁器
組成物は、その用途に応じて信頼性や強度、硬度
等の機械的性質が要求され、また種々の他の材料
と接合して使用されるものや、高温にさらされる
構造部品に使用されるものは機械的性質の外に熱
的諸特性も要求される。
例えば、自動車用エンジンや他の内燃機関の構
造部品として用いられる磁器組成物は、優れた断
熱性と共に高温で十分な強度を有し、かつ摩擦係
数が小さくて耐摩耗性が優れていること、及び高
信頼性のあることなどが要求される。
一方、磁気ヘツドのスライダーやスペーサーに
使用される磁器組成物は、Mn―Zn系フエライ
ト、Ni―Zn系フエライトからなるコアとガラス
溶着して組立てられる。そのため、磁器組成物は
コア材料に用いられる上記フエライトと同等の熱
膨張係数を有するBaO―TiO2系、CaO―TiO2系
非磁性材料が用いられる。
しかし、前記非磁性材料は溶着ガラスと反応し
てガラス内に気孔が発生しやすく、磁気ヘツドと
記録媒体との接触走行時、記録媒体の磁性粉が前
記気孔内に付着したり、チツピングの原因とな
り、また、記録媒体に損傷を与えることがある。
さらに、上記非磁性材料は摩擦係数が大きいた
め、記録媒体及びスライダー表面に傷が生じやす
いなどの問題があつた。
また、磁気ヘツドは前記のごとく、フエライト
からなるコアと非磁性材料からなるスライダーや
スペーサーをガラス溶着することにより、前記非
磁性材料の熱膨張係数をフエライトの熱膨張係数
と合致させる必要があるが、コア材のフエライト
は電磁気的特性によつて定まる組成により熱膨張
係数は決まり、通常90〜120×10-7／℃の熱膨張
係数を有する。
そのため、スライダーやスペーサー用非磁性材
料としては、その熱膨張係数がコア材のフエライ
トの熱膨張係数に合致するように選定できる非磁
性材料が要望されている。
発明の目的
この発明は、前記従来の磁器組成物の欠点を除
去し、非磁性材料の熱膨張係数がコア材のフエラ
イトの熱膨張係数と合致するように組成を変えて
調整することができ、高密度で、かつ摩耗係数が
小さく、磁気ヘツドに組立てる際に、溶着ガラス
との反応性が少なくて溶着ガラス中に気泡の発生
がなく、併せて磁気ヘツドの機械的特性及び動特
性の改善を図つた磁気ヘツド用酸化ジルコニウム
系非磁性磁器組成物を提案するものである。
発明の概要
この発明は、
CeO2、Dy2O3、Y2O3のうち１種以上を５〜35
モル％と、SrO、BaOの１種または２種を20モル
％以下含有し、残部はZrO2及び不可避的不純物
からなる磁気ヘツド用非磁性磁器組成物を要旨と
する。
発明の構成
この発明において組成を限定した理由について
説明する。
CeO2、Dy2O3、Y2O3は磁気ヘツド用非磁性材
料として、その熱膨張係数をコア材料のフエライ
トの熱膨張係数と同等になるよう調整するために
有効である。
そこで、コア材料のフエライトの最低熱膨張係
数90×10-7／℃以上を得るには、いずれか１種ま
たは２種以上を５モル％以上含有する必要があ
る。しかし、35モル％を超えると磁器としての強
度が劣化し、また焼結も困難となり好ましくない
ので、５〜35モル％の範囲に限定した。
なお、CeO2、Dy2O3、Y2O3は、添加される該
酸化物の１部をSm2O3等他の希土類酸化物10モ
ル％以下で置換することができる。
SrO、BaOは、熱膨張係数を選択あるいは調整
して、かつ磁器の焼結性の向上、強度の向上のた
めに有効であるが、そのうちの１種または２種を
20モル％を超えて含有させると、磁器としての強
度の低下が著しく、熱膨張係数の変化が少なく、
コア材のフエライトの熱膨張係数に合致させるた
めの調整が困難となるため、20モル％以下に限定
した。
なお、SrO、BaOは、磁器組成物の熱膨張係数
を微調整するため、添加される該酸化物の１部を
MgO、NiO、ZnO等の他の２価金属酸化物10モ
ル％以下で置換することができる。
ZrO2は、この発明組成物の主成分であるが、
焼結の際の組成の安定化及び焼結性を改善するた
め、ZrO2の一部をTiO2、SnO2の１種または２種
にてZrO2の10モル％以下の範囲で置換すること
ができる。この場合、ZrO2の10モル％を超えて
置換すると、置換した４価の金属酸化物の影響に
より焼結後にひび割れを生じたり、動摩擦係数が
大きくなり、また機械的強度が著しく劣化するの
で好ましくない。
また、この発明においては組成物を安定化する
ために、Nb2O、Ta2O5の１種または２種をZrO2
の10モル％以下の範囲で焼結助剤として含有させ
ることができる。
この発明による磁器組成物は、磁気スライダー
やスペーサーの材料として使用する外、高熱膨張
係数を有するため、パーマロイ、センダスト等の
磁性金属をスライダーや蒸着によつて薄膜化する
際の非磁性基板や前記磁性金属被膜の絶縁材とし
てスパツター、蒸着等により、この発明による磁
器組成物を薄膜化して磁性薄膜上に積層して使用
することもできる。
この発明の非磁性磁器組成物は、粉末冶金法に
よる原料粉末の成型焼結法の外に、懸濁粉末の射
出成型法によつても製造することができる。
実施例
実施例 １
この発明の実施による磁器組成物の一例を次に
示す。
熱膨張係数が95×10-7／℃のNi−Zn系フエ
ライトには、Dy2O3 10モル％、BaO ２モル
％、ZrO2 88モル％の磁器組成物が適合する。
熱膨張係数が105×10-7／℃のMn―Zn系フ
エライトには、CeO2 ９モル％、SrO 11モル
％、ZrO2 80モル％の磁器組成物が適合する。
熱膨張係数が120×10-7／℃のMn―Zn系フ
エライトには、Dy2O3 21モル％、SrO ４モル
％、ZrO2 75モル％の磁器組成物が適合する。
実施例 ２
市販の純度99.5％以上のZrO2、CeO2、Dy2O3、
SrO、BaOを用いて、第１表に示す如く配合して
ボールミルにて混合したのち、仮焼、粉砕、成型
の通常のセラミツクス製造工程を経て、空気中ま
たは酸素中で1360℃〜1470℃の温度で2.0〜4.5時
間加熱して焼結し、この発明の実施による非磁性
磁器組成物No.１〜22を製造した。
また、比較のため、この発明の組成範囲外の組
成からなるNo.23〜29を同一条件で製造した。
上記成品から試料を採取して、密度、抗折力、
硬度、熱膨張係数及び加工性について試験した。
その結果を第１表に焼結条件と共に示す。
なお、加工性は同一加工機を使用して、その主
軸モータの電力増加量をワツト単位で表わし、評
価した値で示した。
Industrial Application Field The present invention relates to a non-magnetic ceramic composition used for structural parts, particularly structural parts for magnetic heads, and the composition is changed to match the thermal expansion coefficient of ferrite as a core material. The present invention relates to a nonmagnetic ceramic composition for a magnetic head that can be adjusted, has a high density, a low coefficient of wear, and has low reactivity with welded glass. BACKGROUND TECHNOLOGY In general, non-magnetic ceramic compositions used as structural parts are required to have mechanical properties such as reliability, strength, and hardness depending on their use, and are also used in conjunction with various other materials. In addition to mechanical properties, thermal properties are also required for materials used in structural components exposed to high temperatures. For example, porcelain compositions used as structural parts of automobile engines and other internal combustion engines have excellent heat insulation properties and sufficient strength at high temperatures, and have a small coefficient of friction and excellent wear resistance. It is also required to have high reliability. On the other hand, the ceramic composition used for the slider and spacer of a magnetic head is assembled by glass welding to a core made of Mn--Zn ferrite or Ni--Zn ferrite. Therefore, for the ceramic composition, a BaO--TiO 2 -based or CaO--TiO 2 -based nonmagnetic material is used, which has a coefficient of thermal expansion equivalent to that of the above-mentioned ferrite used for the core material. However, the non-magnetic material tends to react with the fused glass and create pores in the glass, and when the magnetic head and the recording medium run in contact with each other, magnetic powder from the recording medium may adhere to the pores and cause chipping. This may also cause damage to the recording medium.
Furthermore, since the non-magnetic material has a large coefficient of friction, there have been problems in that the surfaces of the recording medium and slider are easily scratched. Furthermore, as mentioned above, the magnetic head needs to have a core made of ferrite and a slider or spacer made of a non-magnetic material glass welded so that the coefficient of thermal expansion of the non-magnetic material matches the coefficient of thermal expansion of the ferrite. The thermal expansion coefficient of the ferrite core material is determined by the composition determined by the electromagnetic properties, and usually has a thermal expansion coefficient of 90 to 120×10 −7 /°C. Therefore, there is a demand for non-magnetic materials for sliders and spacers that can be selected so that their coefficient of thermal expansion matches that of the ferrite core material. Purpose of the Invention The present invention eliminates the drawbacks of the conventional porcelain compositions, and allows the composition to be adjusted so that the coefficient of thermal expansion of the non-magnetic material matches the coefficient of thermal expansion of the ferrite of the core material. It has a high density and a low wear coefficient, and when assembled into a magnetic head, there is little reactivity with the welded glass, so there is no generation of bubbles in the welded glass, and it also improves the mechanical and dynamic characteristics of the magnetic head. The present invention proposes a zirconium oxide-based nonmagnetic ceramic composition for magnetic heads. Summary of the Invention This invention provides 5 to 35
The gist of the present invention is a nonmagnetic ceramic composition for a magnetic head, which contains 20 mol % or less of one or both of SrO and BaO, with the remainder consisting of ZrO 2 and unavoidable impurities. Structure of the Invention The reason for limiting the composition in this invention will be explained. CeO 2 , Dy 2 O 3 , and Y 2 O 3 are effective as nonmagnetic materials for magnetic heads in order to adjust their coefficient of thermal expansion to be equal to that of ferrite as the core material. Therefore, in order to obtain a minimum coefficient of thermal expansion of 90×10 -7 /° C. or higher for the ferrite core material, it is necessary to contain at least 5 mol % of one or more of these. However, if it exceeds 35 mol%, the strength of the porcelain deteriorates and sintering becomes difficult, which is not preferable, so the content is limited to a range of 5 to 35 mol%. Note that a part of the added oxides of CeO 2 , Dy 2 O 3 , and Y 2 O 3 can be replaced with 10 mol % or less of other rare earth oxides such as Sm 2 O 3 . SrO and BaO are effective for selecting or adjusting the thermal expansion coefficient and improving the sinterability and strength of porcelain, but one or two of them are effective.
If the content exceeds 20 mol%, the strength of the porcelain will decrease significantly, and the coefficient of thermal expansion will change little.
Since it would be difficult to make adjustments to match the coefficient of thermal expansion of the ferrite core material, the content was limited to 20 mol% or less. In addition, SrO and BaO are added in order to finely adjust the coefficient of thermal expansion of the porcelain composition.
It can be replaced with 10 mol% or less of other divalent metal oxides such as MgO, NiO, ZnO, etc. ZrO 2 is the main component of this invention composition,
In order to stabilize the composition during sintering and improve sinterability, a part of ZrO 2 is replaced with one or both of TiO 2 and SnO 2 within a range of 10 mol% or less of ZrO 2 . Can be done. In this case, if more than 10 mol% of ZrO 2 is substituted, cracks may occur after sintering due to the effect of the substituted tetravalent metal oxide, the coefficient of dynamic friction will increase, and the mechanical strength will deteriorate significantly, so it is preferable. do not have. In addition, in this invention, in order to stabilize the composition, one or both of Nb 2 O and Ta 2 O 5 are added to ZrO 2
It can be contained as a sintering aid in a range of 10 mol% or less. In addition to being used as a material for magnetic sliders and spacers, the porcelain composition of the present invention has a high coefficient of thermal expansion. The ceramic composition according to the present invention can also be used as an insulating material for a magnetic metal film by forming it into a thin film by sputtering, vapor deposition, or the like and laminating it on a magnetic thin film. The non-magnetic ceramic composition of the present invention can be manufactured not only by a molding and sintering method of raw material powder using a powder metallurgy method but also by an injection molding method of suspended powder. Examples Example 1 An example of a ceramic composition according to the present invention is shown below. A ceramic composition containing 10 mol % of Dy 2 O 3 , 2 mol % of BaO, and 88 mol % of ZrO 2 is suitable for Ni-Zn ferrite having a coefficient of thermal expansion of 95×10 -7 /°C. A porcelain composition containing 9 mol% of CeO 2 , 11 mol% of SrO, and 80 mol% of ZrO 2 is suitable for Mn--Zn ferrite having a coefficient of thermal expansion of 105×10 -7 /°C. A porcelain composition containing 21 mol% of Dy 2 O 3 , 4 mol% of SrO, and 75 mol% of ZrO 2 is suitable for Mn--Zn ferrite having a coefficient of thermal expansion of 120×10 -7 /°C. Example 2 Commercially available ZrO 2 , CeO 2 , Dy 2 O 3 with a purity of 99.5% or more,
Using SrO and BaO, the mixture is mixed in a ball mill as shown in Table 1, and then subjected to the usual ceramic manufacturing processes of calcining, pulverization, and molding. The compositions were sintered by heating at a temperature of 2.0 to 4.5 hours to produce non-magnetic porcelain compositions Nos. 1 to 22 according to the present invention. For comparison, samples Nos. 23 to 29 having compositions outside the composition range of this invention were manufactured under the same conditions. A sample was taken from the above product and the density, transverse rupture strength,
Hardness, coefficient of thermal expansion and workability were tested.
The results are shown in Table 1 along with the sintering conditions. The workability was evaluated using the same processing machine and expressed in watts as an increase in the power of the spindle motor.
【表】【table】
【表】
発明の効果
この発明は、ZrO2に、特定量のCeO2、Dy2O3、
Y2O3のうち１種以上と、SrO、BaOの１種また
は２種とを複合含有させることにより、コア材の
フエライトと同等の熱膨張係数を得ることがで
き、しかも組成を変えることにより、フエライト
の熱膨張係数に合致するように調整することがで
きる。
さらに、高密度で摩耗係数が小さく、磁気ヘツ
ドに組立てる際、溶着ガラス中に気泡を発生させ
ることがないので、磁気ヘツド用として最適の非
磁性磁器組成物が得られる。[Table] Effects of the invention This invention provides ZrO 2 with specific amounts of CeO 2 , Dy 2 O 3 ,
By containing one or more of Y 2 O 3 and one or two of SrO and BaO in combination, it is possible to obtain a thermal expansion coefficient equivalent to that of ferrite as a core material, and by changing the composition. , can be adjusted to match the thermal expansion coefficient of ferrite. Furthermore, it has a high density and a low coefficient of wear, and does not generate bubbles in the welded glass when assembled into a magnetic head, making it possible to obtain a non-magnetic ceramic composition that is most suitable for use in magnetic heads.
Claims (1)
35モル％と、SrO、BaOの１種または２種を20モ
ル％以下含有し、残部はZrO2及び不可避的不純
物からなることを特徴とする磁気ヘツド用非磁性
磁器組成物。1 One or more of CeO 2 , Dy 2 O 3 , Y 2 O 3 in 5 to
1. A non-magnetic ceramic composition for a magnetic head, characterized in that it contains 35 mol % of one or both of SrO and BaO, and 20 mol % or less of one or both of SrO and BaO, with the remainder consisting of ZrO 2 and inevitable impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60122033A JPS61281067A (en) | 1985-06-05 | 1985-06-05 | Non-magnetic ceramic composition for magnetic head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60122033A JPS61281067A (en) | 1985-06-05 | 1985-06-05 | Non-magnetic ceramic composition for magnetic head |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61281067A JPS61281067A (en) | 1986-12-11 |
| JPH0228538B2 true JPH0228538B2 (en) | 1990-06-25 |
Family
ID=14825928
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60122033A Granted JPS61281067A (en) | 1985-06-05 | 1985-06-05 | Non-magnetic ceramic composition for magnetic head |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61281067A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5741747A (en) * | 1996-05-16 | 1998-04-21 | Council Of Scientific & Industrial Research | Ceramic substrate for bi-cuprate superconductors and a process for preparing the same |
-
1985
- 1985-06-05 JP JP60122033A patent/JPS61281067A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61281067A (en) | 1986-12-11 |
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