JPH02109306A - Manufacture of mn-zn ferrite for magnetic head core - Google Patents
Manufacture of mn-zn ferrite for magnetic head coreInfo
- Publication number
- JPH02109306A JPH02109306A JP63261733A JP26173388A JPH02109306A JP H02109306 A JPH02109306 A JP H02109306A JP 63261733 A JP63261733 A JP 63261733A JP 26173388 A JP26173388 A JP 26173388A JP H02109306 A JPH02109306 A JP H02109306A
- Authority
- JP
- Japan
- Prior art keywords
- ferrite
- heat treatment
- temperature
- atmosphere
- density
- 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.)
- Pending
Links
- 229910000859 α-Fe Inorganic materials 0.000 title claims abstract description 29
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 11
- 238000010438 heat treatment Methods 0.000 claims abstract description 32
- 239000000463 material Substances 0.000 claims abstract description 7
- 239000012299 nitrogen atmosphere Substances 0.000 claims abstract description 5
- 238000001513 hot isostatic pressing Methods 0.000 claims description 10
- 238000005245 sintering Methods 0.000 abstract description 12
- 238000001556 precipitation Methods 0.000 abstract description 5
- 230000002706 hydrostatic effect Effects 0.000 abstract 2
- 239000012298 atmosphere Substances 0.000 description 15
- 239000011148 porous material Substances 0.000 description 12
- 238000000034 method Methods 0.000 description 8
- 239000011701 zinc Substances 0.000 description 7
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 6
- 229910052760 oxygen Inorganic materials 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 230000006866 deterioration Effects 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 230000035699 permeability Effects 0.000 description 4
- 230000001590 oxidative effect Effects 0.000 description 3
- 239000011787 zinc oxide Substances 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 238000001354 calcination Methods 0.000 description 2
- 239000011162 core material Substances 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- AMWRITDGCCNYAT-UHFFFAOYSA-L hydroxy(oxo)manganese;manganese Chemical compound [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 229910018605 Ni—Zn Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Landscapes
- Magnetic Ceramics (AREA)
- Magnetic Heads (AREA)
- Soft Magnetic Materials (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は磁気ヘッドコア材料として用いられる高密度Ｍ
ｎ−Ｚｎフェライトの製造方法に係る。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a high-density magnetic material used as a magnetic head core material.
The present invention relates to a method for manufacturing n-Zn ferrite.
〔従来の技術］
磁気へラドコア材として用いられるフェライト材料とし
ては、加工性、耐摩耗性等の機械的性質及び、磁気特性
に優れることが要求される。この要求を満たす材料とし
て、従来のＮｉ−Ｚｎフェライトに代わり、高密度のＭ
ｎ−Ｚｎフェライトが多く用いられる傾向にある。この
高密度Ｍｎ−Ｚｎフェライトの製造方法としては、−次
焼結後、熱間静水圧プレスを施すという方法が知られて
いる（特開昭５３−５１２１７＞、 Ｌかし、熱間静水
圧プレスを施したフェライトは、かなりの高圧で処理さ
れるため、内部にかなりの歪が残存しており、そのため
、加工時に、欠け、割れが生じやすいという欠点がある
。そこで、この内部歪を除去するために、熱処理を行う
という方法が知られている（時開５３−３３３９２、特
開昭５４−６９７９５ 、特開昭５５−３２７６４ 、
特開昭５５−３２７６５）、その熱処理の温度に関して
は、例えば、５００℃〜８００℃で行うと、空孔の膨張
を生じないこと（特開昭５５−３２７６５）、また、８
００℃〜１１００℃で行うと、抗折強度が増加すること
（特開昭５５−３２７６４）等が知られているが、熱処
理時の雰囲気に関しては、これら文献には全く言及され
ていない。[Prior Art] A ferrite material used as a magnetic herad core material is required to have excellent mechanical properties such as workability and wear resistance, and excellent magnetic properties. In place of the conventional Ni-Zn ferrite, high-density M
There is a tendency that n-Zn ferrite is often used. As a method for manufacturing this high-density Mn-Zn ferrite, a method is known in which hot isostatic pressing is performed after secondary sintering (Japanese Unexamined Patent Publication No. 53-51217, L Pressing, Hot Isostatic Pressing) Pressed ferrite is processed under very high pressure, so there is a considerable amount of strain left inside, which has the disadvantage of being prone to chipping and cracking during processing.Therefore, this internal strain is removed. In order to do this, a method of heat treatment is known.
Regarding the temperature of the heat treatment, for example, if it is carried out at 500°C to 800°C, no expansion of the pores will occur (Japanese Patent Application Laid-open No. 55-32765), and 8
It is known that the bending strength increases when heat treatment is carried out at a temperature of 00°C to 1100°C (Japanese Patent Application Laid-Open No. 55-32764), but these documents do not mention the atmosphere during heat treatment at all.
更にまた、より高い温度で熱処理することも知られてお
り、例えば、１０００℃〜１１００℃の温度で空気中で
熱処理を行うと磁気特性が向上することが特開昭５３−
３３９２で、また、９００°Ｃ〜１３００℃の温度でＮ
２雰囲気中で熱処理を行うことも特開昭５４−６９７９
５で提案されている。Furthermore, it is also known that heat treatment can be performed at higher temperatures; for example, it has been reported in JP-A-53-1989 that magnetic properties are improved when heat treatment is performed in air at a temperature of 1000°C to 1100°C.
3392, and also N at temperatures between 900°C and 1300°C.
2 It is also possible to perform heat treatment in an atmosphere as described in Japanese Patent Application Laid-Open No. 54-6979.
5 is proposed.
しかしながら本発明者らが種々実験検討を加えた結果、
熱間静水圧プレス後、フェライトの熱処理に関しては、
その温度のみならず雰囲気にも特に留意しなければなら
ないことが判明した。However, as a result of various experimental studies conducted by the present inventors,
Regarding heat treatment of ferrite after hot isostatic pressing,
It has been found that special attention must be paid not only to the temperature but also to the atmosphere.
すなわち熱処理を９００℃以上という高い温度で行うと
、熱間静水圧プレス処理に依り高密度化を図っているに
もかかわらず、その後の熱処理により、空孔が復帰して
しまうことがある。一方、４００℃以下の低温で行うと
、内部歪が除去されず、加工時の欠け、割れが多く発生
する。また、熱処理を空気中あるいは、酸化雰囲気中で
行うと、フェライト焼結体の表面付近のみが酸化され、
フェライト焼結体の表面付近では磁気特性が劣化し、焼
結体の内部とで磁気特性の不均一が生ずる。更に、酸化
が過度に行われると、焼結体表面付近に、α−ＦｅｚＯ
ｚの異相が析出し問題となることも判明しそれ故に、本
発明の方法は熱処理により内部歪を除去し、しかも空孔
の復帰もなく、加えて、フェライトの焼結体表面付近で
の磁気特性の劣化がなく、異相の析出もない高密度Ｍｎ
−Ｚｎフェライトの製造方法を提供するものである。That is, if the heat treatment is performed at a high temperature of 900° C. or higher, the pores may return due to the subsequent heat treatment, even though densification is achieved by hot isostatic pressing. On the other hand, if processing is carried out at a low temperature of 400° C. or lower, internal strains will not be removed and many chips and cracks will occur during processing. Additionally, if heat treatment is performed in air or in an oxidizing atmosphere, only the surface area of the ferrite sintered body will be oxidized.
The magnetic properties deteriorate near the surface of the ferrite sintered body, and the magnetic properties become non-uniform with respect to the inside of the sintered body. Furthermore, if oxidation is excessive, α-FezO is formed near the surface of the sintered body.
It has also been found that a different phase of z precipitates and causes a problem.Therefore, the method of the present invention eliminates the internal strain by heat treatment, does not restore the pores, and in addition, reduces the magnetic field near the surface of the ferrite sintered body. High-density Mn with no deterioration of properties and no precipitation of foreign phases
- A method for manufacturing Zn ferrite is provided.
本発明は、高密度Ｍｎ −Ｚｎｎフシイ［・の製造方法
において、フェライト材を一次焼結した後、熱間静水圧
プレスを行い、その後、Ｎ２雰囲気中で、４００℃〜９
００℃の温度で熱処理を行うことを特徴とする高密度Ｍ
ｎ−Ｚｎフェライトの製造方法である。The present invention is a method for producing high-density Mn-Znn steel.After primary sintering of ferrite material, hot isostatic pressing is carried out, and then in an N2 atmosphere, 400°C to 90°C
High-density M characterized by heat treatment at a temperature of 00°C
This is a method for manufacturing n-Zn ferrite.
本発明の方法により高密度フェライトを製造するには、
酸化鉄を５０〜６０ｍｏｌχ、酸化亜鉛を５〜２５ｍｏ
ｌχ残りを酸化マンガンから成る様に秤量し、それに副
成分として、例えばＣａＯを０．５ｗｔ％以下含有せし
め、ボールミルにて混合し、スビ名ル化が４０〜８０χ
程度に進行する様な温度で仮焼し、その後、−次焼結を
行う。−次焼結に際しては、その温度と雰囲気を適切に
選ぶ必要がある。温度が１１００℃以下であると、焼結
密度が理論密度に対し９０％以下となり、かつオープン
ボアを生ずる。これに対し、温度が１３００°Ｃを越え
ると、異常粒成長をおこし、加工時に大きな欠けを生じ
やすい。また、−次焼結の雰囲気は、酸素分圧を適当に
選ぶことが重要であり、酸素分圧が必要以上に高いと・
焼結時にα−ＦｅｚＯ：ｉが析出し、酸素分圧が必要以
上に低すぎると、フェライトにクラックを生しやすい。To produce high-density ferrite by the method of the present invention,
50 to 60 mol χ of iron oxide, 5 to 25 mo of zinc oxide
Weigh the remaining lχ so that it consists of manganese oxide, add 0.5 wt% or less of CaO as a subcomponent, mix it in a ball mill, and make it 40 to 80 x
Calcination is performed at such a temperature that the sintering progresses to a certain degree, and then -subsequent sintering is performed. - For the next sintering, it is necessary to select the temperature and atmosphere appropriately. If the temperature is 1100° C. or less, the sintered density will be 90% or less of the theoretical density, and open bores will occur. On the other hand, if the temperature exceeds 1300°C, abnormal grain growth occurs and large chips are likely to occur during processing. In addition, it is important to select an appropriate oxygen partial pressure in the atmosphere for secondary sintering, and if the oxygen partial pressure is higher than necessary,
α-FezO:i precipitates during sintering, and if the oxygen partial pressure is lower than necessary, cracks are likely to occur in the ferrite.
この−次焼結により得られたフェライト焼結体には、熱
間静水圧プレスを施し高密度化する。The ferrite sintered body obtained by this secondary sintering is subjected to hot isostatic pressing to increase its density.
その際にも、温度が重要であり、−次焼結の温度をはる
かに越える温度で行うと、粒成長を起こす。Temperature is also important in this case, and grain growth will occur if the temperature is much higher than the temperature for secondary sintering.
また圧力も３００〜２０００気圧が望ましく、３００気
圧以下では高密度化が図れない。この熱間静水圧プレス
処理後に熱処理を行なうが、この熱処理については前記
のごとく、その温度と雰囲気が非常に重要である。温度
が４００℃以下では、内部歪が完全に除去されず、加工
時に欠け、割れが多く発生する。温度が４００℃〜６０
０℃の範囲であると、欠は割れはかなり改善されるが、
若干発生するため最適な温度は６００℃以−トである。Further, the pressure is preferably 300 to 2000 atm, and if it is less than 300 atm, high density cannot be achieved. After this hot isostatic pressing treatment, heat treatment is performed, and as mentioned above, the temperature and atmosphere are very important for this heat treatment. If the temperature is below 400°C, internal strain will not be completely removed and many chips and cracks will occur during processing. Temperature is 400℃~60℃
If the temperature is in the 0℃ range, the cracking will be considerably improved, but
The optimum temperature is 600° C. or higher because some amount of heat is generated.
しかし９００℃以トとなると内部歪は完全に除去される
が、空孔の復帰が、急激に進む。従って熱処理の温度と
しては４００℃以上９００℃未満が望ましい。また、熱
処理時の雰囲気に関しては、熱処理を、空気中あるいは
酸化雰囲気中で行うと、フェライト焼結体の表面付近が
酸化され、焼結体の表面での磁気特性が、焼結体内部に
比し、大きく劣化してしまう。However, when the temperature reaches 900° C. or higher, the internal strain is completely removed, but the pores rapidly recover. Therefore, the temperature of the heat treatment is preferably 400°C or more and less than 900°C. Regarding the atmosphere during heat treatment, if heat treatment is performed in air or an oxidizing atmosphere, the vicinity of the surface of the ferrite sintered body will be oxidized, and the magnetic properties at the surface of the sintered body will be different from those inside the sintered body. However, it deteriorates significantly.
また、酸化が過度に行われた場合には、形状にも依るが
焼結体表面から約３１程度までα−Ｆｅ、Ｏ：Ｊの異相
が析出する。この様な現象は、酸素分圧を１％程度まで
下げても同様であり、熱処理時の雰囲気は、酸素分圧が
０．５％以下かあるいはＮ２雰囲気中が望ましい。また
真空中でも、同様な効果が得られることも判明している
。Further, if oxidation is excessively performed, different phases of α-Fe and O:J are precipitated from the surface of the sintered body to about 31 mm, although it depends on the shape. This phenomenon remains the same even when the oxygen partial pressure is lowered to about 1%, and the atmosphere during the heat treatment is preferably an oxygen partial pressure of 0.5% or less or an N2 atmosphere. It has also been found that similar effects can be obtained even in a vacuum.
以上の工程を経ることにより、内部歪がなく、しかも空
孔の復帰もなく、加えて焼結体表面付近での磁気特性の
劣化がなく、異相の析出もない、高密度Ｍｎ−Ｚｎフェ
ライトを製造することができ、精密加工性及び磁気特性
を大幅に向上することができる。By going through the above steps, we can produce high-density Mn-Zn ferrite that has no internal strain, no return of pores, no deterioration of magnetic properties near the surface of the sintered body, and no precipitation of foreign phases. The precision processability and magnetic properties can be greatly improved.
Ｃ実施例〕
（実施例１）
ＦｅｚＯ１，：５３．５ｍｏ１χ、ＺｎＯ：１５．５ｍ
ｏｌχ、 ＭｎＯ：３１．０１ｌｌｏＨとなる様に原料
を秤量し、混合仮焼した後、１２５０℃で一次焼結を行
い、更に針ガス中で１２００℃１０００気圧で熱間静水
圧プレスをした。Example C] (Example 1) FezO1: 53.5mol1χ, ZnO: 15.5m
The raw materials were weighed so that MnO: 31.01lloH, mixed and calcined, and then primary sintered at 1250°C, and then hot isostatically pressed at 1200°C and 1000 atm in needle gas.
その後、５００℃〜１１００℃ＮＺ雰囲気で熱処理をし
た。得られた焼結体の単位面積当りの１μｍ以上の空孔
の数を第１図に示す。熱処理温度が９００℃以下では１
μｍ以上の空孔は、はとんど存在せず、９００℃以下で
あれば、空孔の数は温度に依らない。Thereafter, heat treatment was performed at 500°C to 1100°C in a NZ atmosphere. The number of pores of 1 μm or more per unit area of the obtained sintered body is shown in FIG. 1 when the heat treatment temperature is below 900℃
There are hardly any pores larger than μm, and the number of pores does not depend on the temperature as long as it is below 900°C.
それに対し、熱処理の温度が９００ ’Ｃを越えると、
空孔は急激に増加する傾向にある。従って空孔の復帰を
おさえるには、９００℃以下が望ましい。On the other hand, when the heat treatment temperature exceeds 900'C,
The number of vacancies tends to increase rapidly. Therefore, in order to suppress the return of pores, the temperature is preferably 900° C. or lower.
（実施例２）
ＦｅｚＯｔ：５３．５ｍｏｌχ、ＺｎＯ：１５．５ｍｏ
ｌχ、 ＭｎＯ：３１．Ｏｍｏｌχとなる様に原料を秤
潰し、混合仮焼した後、１２５０℃で一次焼結を行い、
更にＡｒガス中で１２００°ｃ１．０００気圧で熱間静
水圧プレスをした。(Example 2) FezOt: 53.5molχ, ZnO: 15.5mol
lχ, MnO: 31. After weighing and crushing the raw materials to obtain Omolχ, mixing and calcining, primary sintering is performed at 1250°C.
Further, hot isostatic pressing was performed at 1200°C and 1.000 atm in Ar gas.
その後、６００°Ｃ〜１０５０°Ｃの／！Ａ１変で、熱
処理時の雰囲気を変え、熱処理を行った。これにより得
られたフェライト焼結体の表面付近と中心部より外径８
φｍｍ、 内径４φ１１１１．厚さ０．５ｍｓのリング
切り出しＩＭＨｚ、５財２での透磁率を測定した。第１
表は、その測定結果である。熱処理時の雰囲気を、空気
中あるいは、酸化雰囲気中で行うと、焼結体表面での透
磁率が、焼結体内部に比べ低下するのに対し、Ｎｔ雰囲
気中で処理したものは、焼結体表面での透磁率の低下は
なく、焼結体内部で均一である。After that, /! of 600°C to 1050°C! Heat treatment was performed by changing the atmosphere during heat treatment in A1 variation. The outer diameter of the ferrite sintered body thus obtained is 8
φmm, inner diameter 4φ1111. The magnetic permeability of a ring cut out with a thickness of 0.5 ms was measured at IMHz and 5 materials 2. 1st
The table shows the measurement results. If the heat treatment is carried out in air or an oxidizing atmosphere, the magnetic permeability at the surface of the sintered body will be lower than that inside the sintered body, but when the heat treatment is carried out in an Nt atmosphere, the sintered There is no decrease in magnetic permeability on the body surface, and it is uniform inside the sintered body.
以上の実施例より明らかな様に、熱間静水圧プレス後の
熱処理を４００〜９００′Ｃの温度で、しかもＮ、雰囲
気中で行うことにより、空孔の復帰もなく焼結体表面で
の透磁率の劣化もな（、さらに異相の析出もない高密度
フェライトが得られる。As is clear from the above examples, by performing the heat treatment after hot isostatic pressing at a temperature of 400 to 900'C in a N atmosphere, no pores return and the surface of the sintered body is High-density ferrite with no deterioration in magnetic permeability (and no precipitation of foreign phases) can be obtained.
以上説明した様に、本発明の製造方法による高密度Ｍｎ
−Ｚｎフェライトは、内部歪のために加工時の欠は割
れも少なく、しかも空孔の復帰もなく、加えて成形体表
面付近での磁気特性の劣化がなく、また焼結体表面付近
での異相の析出もなく、従来の製造方法と比して、ｔ＃
密加工性及び磁気特性が大幅に向上している。As explained above, high-density Mn by the manufacturing method of the present invention
-Zn ferrite has few cracks during processing due to internal strain, and there is no recovery of pores.In addition, there is no deterioration of magnetic properties near the surface of the compact, and there is no deterioration of the magnetic properties near the surface of the sintered compact. There is no precipitation of foreign phases, and compared to conventional manufacturing methods, t#
Dense workability and magnetic properties are significantly improved.
第１図は、熱処理の温度と空孔数の関係を示すグラフで
ある。FIG. 1 is a graph showing the relationship between the heat treatment temperature and the number of pores.
Claims (1)
い、その後、熱処理を行う高密度Ｎｎ−Ｚｎフェライト
の製造方法において、上記熱処理を、Ｎ＿２雰囲気中で
、４００℃〜９００℃の温度で行うことを特徴とする高
密度Ｍｎ−Ｚｎフェライトの製造方法。In a method for producing high-density Nn-Zn ferrite in which a ferrite material is primarily sintered, hot isostatic pressing is performed, and then heat treatment is performed, the above heat treatment is performed at a temperature of 400°C to 900°C in an N_2 atmosphere. A method for producing high-density Mn-Zn ferrite, characterized by carrying out the following steps.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63261733A JPH02109306A (en) | 1988-10-18 | 1988-10-18 | Manufacture of mn-zn ferrite for magnetic head core |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63261733A JPH02109306A (en) | 1988-10-18 | 1988-10-18 | Manufacture of mn-zn ferrite for magnetic head core |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02109306A true JPH02109306A (en) | 1990-04-23 |
Family
ID=17365956
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63261733A Pending JPH02109306A (en) | 1988-10-18 | 1988-10-18 | Manufacture of mn-zn ferrite for magnetic head core |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02109306A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5302306A (en) * | 1991-03-15 | 1994-04-12 | Sony Corporation | Process for preparing polycrystalline ferrite materials and composites containing them |
-
1988
- 1988-10-18 JP JP63261733A patent/JPH02109306A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5302306A (en) * | 1991-03-15 | 1994-04-12 | Sony Corporation | Process for preparing polycrystalline ferrite materials and composites containing them |
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