JPH04320009A - Fabrication of anisotropic oxide permanent magnet - Google Patents
Fabrication of anisotropic oxide permanent magnetInfo
- Publication number
- JPH04320009A JPH04320009A JP3112172A JP11217291A JPH04320009A JP H04320009 A JPH04320009 A JP H04320009A JP 3112172 A JP3112172 A JP 3112172A JP 11217291 A JP11217291 A JP 11217291A JP H04320009 A JPH04320009 A JP H04320009A
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- Prior art keywords
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- fine powder
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- Prior art date
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- 238000004519 manufacturing process Methods 0.000 title claims abstract description 10
- 239000000843 powder Substances 0.000 claims abstract description 46
- 239000002245 particle Substances 0.000 claims abstract description 27
- 238000009826 distribution Methods 0.000 claims abstract description 22
- 238000000034 method Methods 0.000 claims abstract description 14
- 238000001354 calcination Methods 0.000 claims abstract description 7
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 claims abstract description 6
- 239000000203 mixture Substances 0.000 claims abstract description 6
- 238000010304 firing Methods 0.000 claims abstract description 3
- LEDMRZGFZIAGGB-UHFFFAOYSA-L strontium carbonate Chemical compound [Sr+2].[O-]C([O-])=O LEDMRZGFZIAGGB-UHFFFAOYSA-L 0.000 claims abstract description 3
- 229910000018 strontium carbonate Inorganic materials 0.000 claims abstract description 3
- 238000010298 pulverizing process Methods 0.000 claims description 4
- 238000000465 moulding Methods 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 abstract 1
- 229910000859 α-Fe Inorganic materials 0.000 description 14
- 239000013078 crystal Substances 0.000 description 10
- 239000011362 coarse particle Substances 0.000 description 6
- 230000006866 deterioration Effects 0.000 description 6
- 238000007796 conventional method Methods 0.000 description 4
- 238000005245 sintering Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 239000011882 ultra-fine particle Substances 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000000654 additive Substances 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
Landscapes
- Manufacturing Cores, Coils, And Magnets (AREA)
- Hard Magnetic Materials (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は、異方性酸化物永久磁石
の製造方法に関し、特に、高残留磁束密度（以下、これ
を単に「Ｂｒ」と略記する。）で、かつ高保磁力（以下
、これを単に「ｉＨｃ」と略記する。）を有する異方性
フェライト磁石の製造方法に関するものである。[Industrial Field of Application] The present invention relates to a method for manufacturing anisotropic oxide permanent magnets, and in particular, to a method for producing anisotropic oxide permanent magnets, in particular those with high residual magnetic flux density (hereinafter simply referred to as "Br") and high coercive force (hereinafter simply referred to as "Br"). , which is simply abbreviated as "iHc").
【０００２】0002
【従来の技術】一般に、異方性酸化物永久磁石、例えば
異方性フェライト磁石（以下はこの例で述べる）は、Ｆ
ｅ２Ｏ３ とＭＯ化合物（ただし、Ｍ は Ｓｒ，Ｂａ
，Ｐｂ ｅｔｃ．）を所定のモル比になるように配合し
、仮焼、粉砕、成形および焼結という各工程を経て製造
される。[Prior Art] Generally, anisotropic oxide permanent magnets, such as anisotropic ferrite magnets (described below using this example), are F
e2O3 and MO compound (M is Sr, Ba
, Pb etc. ) are blended in a predetermined molar ratio, and manufactured through the steps of calcination, crushing, molding, and sintering.
【０００３】この異方性フェライト磁石について、これ
の前記Ｂｒは高いのものが望ましいが、このような高い
Ｂｒ値のものを得るには、焼結体の密度や結晶の配向度
を高めることが有効である。一方、前記ｉＨｃについて
も、その値の高いものほど望ましいが、その向上のため
には、単磁区結晶の存在率を高くすることが必要である
。It is desirable for this anisotropic ferrite magnet to have a high Br value, but in order to obtain such a high Br value, it is necessary to increase the density of the sintered body and the degree of crystal orientation. It is valid. On the other hand, as for iHc, a higher value is more desirable, but in order to improve it, it is necessary to increase the abundance of single-domain crystals.
【０００４】従来、前記異方性フェライト磁石の磁気特
性（Ｂｒ，ｉＨｃ）を向上させる研究というのは、主と
して、磁場成形方法や主成分および微量添加物の配合割
合等についてのものが主流となっていた。しかしながら
、これらの研究にもかかわらず、実際には、仮焼後の粗
粉をボールミルや振動ミル、アトライター、ジェットミ
ル等の機械的手段で微粉砕していたため、０．１ μｍ
以下の超微粒子から１．５ μｍ以上の粗大粒子に至る
まで幅広い粒度分布が生じてしまい、ＢｒやｉＨｃの著
しい劣化が避けられなかった。すなわち、０．１μｍ以
下の超微粒子が発生した場合は、焼結体の高密度化や結
晶の配向度が悪くなり、また、１．５ μｍ以上の粗大
粒子が発生した場合は、焼結体中の多磁区結晶粒子の割
合が多くなって、前記Ｂｒや前記ｉＨｃの低下を招く結
果となった。[0004] Conventionally, research on improving the magnetic properties (Br, iHc) of the anisotropic ferrite magnets has mainly focused on magnetic field forming methods and the proportions of main components and trace additives. was. However, despite these studies, in reality, the coarse powder after calcination was finely pulverized by mechanical means such as ball mills, vibration mills, attritors, jet mills, etc.
A wide particle size distribution was generated, ranging from ultrafine particles below to coarse particles of 1.5 μm or more, and significant deterioration of Br and iHc was unavoidable. In other words, if ultrafine particles of 0.1 μm or less are generated, the density of the sintered body and crystal orientation will be poor, and if coarse particles of 1.5 μm or more are generated, the sintered body will be damaged. The ratio of multi-domain crystal grains inside increased, resulting in a decrease in the Br and iHc.
【０００５】また、この種の異方性フェライト磁石の場
合、焼結体の結晶粒子を単磁区結晶粒子とするには、そ
の粒子径を、約０．１ 〜１．５ μｍの範囲とするこ
とが好適であるとされている。そして、そのためには、
焼結工程での粒成長を考慮した場合、粉砕に当って粒径
が１．５ μｍより微細になるようにする必要があった
。しかしながら、このような処理は、上述したような超
微粒子（−０．１ μｍ）を増加させすぎ、また粗大粒
子（＋１．５ μｍ）を完全に除去することはできなか
った。In the case of this type of anisotropic ferrite magnet, in order to make the crystal grains of the sintered body single-domain crystal grains, the grain size should be in the range of about 0.1 to 1.5 μm. It is said that this is preferable. And for that,
Considering grain growth during the sintering process, it was necessary to make the grain size finer than 1.5 μm during pulverization. However, such treatment excessively increased the amount of ultrafine particles (-0.1 μm) as described above, and could not completely remove coarse particles (+1.5 μm).
【０００６】これに対して、近年、仮焼物の微粉砕粉を
分級して高Ｂｒおよび高ｉＨｃ化を図る試みがなされて
いる。例えば、特開昭５７−１３０４０３号公報では、
微粉砕粉を磁気変態点以上の温度において分級する方法
を提案している。また、特開平１−１４７８０９号公報
では、原料酸化鉄あるいは微粉砕粉をその粒度分布の理
想とする標準偏差内に分級する方法を提案している。On the other hand, in recent years, attempts have been made to classify finely pulverized powder of calcined products to achieve high Br and high iHc. For example, in Japanese Patent Application Laid-Open No. 57-130403,
We have proposed a method for classifying finely pulverized powder at a temperature above the magnetic transformation point. Further, JP-A-1-147809 proposes a method of classifying raw iron oxide or finely pulverized powder to within an ideal standard deviation of its particle size distribution.
【０００７】[0007]
【発明が解決しようとする課題】ところが、前記特開昭
５７−１３０４０３号公報開示の方法は、粗大粉および
微細粉を分級除去する方法について究明しているが、そ
の分級粉の粒度分布まで言及していない。また、特開平
１−１４７８０９号公報開示の方法は、粉末の粒度分布
を平均粒径と標準偏差により表現しているが、その微粉
砕粉の平均粒径と標準偏差値から判断すると、０．１
μｍ未満の微細粉の量が少なすぎるため、却って焼結時
の密度が高くならず、そのために磁気特性が向上しない
という問題点があった。従って、各従来技術は異方性フ
ェライト磁石の高Ｂｒおよび高ｉＨｃ化には未だ不十分
であった。[Problems to be Solved by the Invention] However, although the method disclosed in JP-A-57-130403 investigates a method for classifying and removing coarse powder and fine powder, it does not even mention the particle size distribution of the classified powder. I haven't. Furthermore, in the method disclosed in JP-A-1-147809, the particle size distribution of powder is expressed by the average particle size and standard deviation, but judging from the average particle size and standard deviation of the finely pulverized powder, 0. 1
Since the amount of fine powder of less than μm was too small, the density during sintering did not increase, which caused the problem that the magnetic properties did not improve. Therefore, each of the conventional techniques is still insufficient for increasing the Br and iHc of anisotropic ferrite magnets.
【０００８】本発明の目的は、これら従来技術の抱える
問題点を克服することにあり、特に、高Ｂｒで、かつ高
ｉＨｃの異方性フェライト磁石を得ることのできる製造
方法を提供することにある。The purpose of the present invention is to overcome the problems faced by these conventional techniques, and in particular to provide a manufacturing method capable of obtaining an anisotropic ferrite magnet with high Br and high iHc. be.
【０００９】[0009]
【課題を解決するための手段】上掲の目的実現のために
鋭意研究した結果、本発明者らは、微粉砕後の粉末の粒
度分布が磁気特性に及ぼす影響が大きいことを知見した
。そこで、この粒度分布を種々変化させてさらに検討を
行った結果、異方性フェライト磁石の高Ｂｒおよび高ｉ
Ｈｃ化のための理想的な微粉砕粉の粒度分布を見出し、
本発明に想到した。[Means for Solving the Problems] As a result of intensive research aimed at achieving the above-mentioned object, the present inventors found that the particle size distribution of the powder after pulverization has a large influence on the magnetic properties. Therefore, as a result of further investigation with various changes in this particle size distribution, we found that anisotropic ferrite magnets with high Br and high i
Discovered the ideal particle size distribution of finely pulverized powder for Hc conversion,
The present invention was conceived.
【００１０】すなわち、本発明は、Ｆｅ２Ｏ３ とＳｒ
ＣＯ３の混合物を仮焼し粉砕して得られる微粉末を磁場
中で成形し、その後本焼成して異方性酸化物永久磁石を
製造する方法において、上記混合物をＦｅ２Ｏ３ とＳ
ｒＯ とのモル比が５．３ 〜６．１ になるように仮
焼し、次いでその仮焼物を微粉砕し、得られた微粉末を
、空気透過法で表わされる平均粒径が０．６ 〜１．０
μｍで、体積割合で表わした粒度分布の半値幅が０．
２ μｍ以下で、１．５ μｍ以上の粗大粉が１体積％
以下で、そして０．１ μｍ以下の微細粉が０．５ 〜
２．０体積％となるように分級調整し、その後磁場成形
に付することを特徴とする異方性酸化物永久磁石の製造
方法である。[0010] That is, the present invention provides Fe2O3 and Sr
In a method of manufacturing an anisotropic oxide permanent magnet by calcining and pulverizing a mixture of CO3, molding the fine powder obtained in a magnetic field, and then main firing, the above mixture is mixed with Fe2O3 and S
It is calcined so that the molar ratio with rO is 5.3 to 6.1, and then the calcined product is finely pulverized, and the resulting fine powder has an average particle size of 0.6 as measured by the air permeation method. ~1.0
In μm, the half width of the particle size distribution expressed as a volume fraction is 0.
1% by volume of coarse powder of 2 μm or less and 1.5 μm or more
and the fine powder of 0.1 μm or less is 0.5 ~
This is a method for producing an anisotropic oxide permanent magnet, which is characterized in that the classification is adjusted to 2.0% by volume, and then subjected to magnetic field forming.
【００１１】[0011]
【作用】本発明の上記構成において、仮焼物のＦｅ２Ｏ
３ とＳｒＯ とのモル比ｎを５．３ 〜６．１とした
理由は、このモル比ｎが５．３ 未満になると、仮焼時
の結晶粒成長が著しく大きくなるためｉＨｃが低下し、
一方、このモル比が６．１ を超えると、短時間ではフ
ェライト化反応が十分に起らず、過剰の Ｆｅ２Ｏ３が
残留し、Ｂｒの劣化をもたらすからである。[Operation] In the above structure of the present invention, Fe2O of the calcined material is
The reason why the molar ratio n of 3 and SrO is set to 5.3 to 6.1 is that when this molar ratio n becomes less than 5.3, the crystal grain growth during calcination increases significantly, resulting in a decrease in iHc.
On the other hand, if this molar ratio exceeds 6.1, the ferrite reaction will not occur sufficiently in a short time, and excessive Fe2O3 will remain, resulting in deterioration of Br.
【００１２】また、微粉末の空気透過法による平均粒径
の測定値を０．６ 〜１．０ μｍの範囲に限定した理
由は、０．６ μｍ未満の場合、微粉砕に長時間を要す
るため工業生産に向かず、１．０ μｍを超えると、粗
大粒が多くなり、粒度分布を構成する微粉末の回収率が
低下するためである。[0012] Furthermore, the reason why the average particle diameter measured by the air permeation method of fine powder was limited to the range of 0.6 to 1.0 μm is that if the diameter is less than 0.6 μm, it takes a long time to pulverize. Therefore, it is not suitable for industrial production, and if it exceeds 1.0 μm, the number of coarse particles increases and the recovery rate of fine powder that makes up the particle size distribution decreases.
【００１３】また、粒度分布の半値幅を０．２ μｍ以
下とした理由は、それを超えると、焼結時の粒成長のバ
ラツキが大きくなり、異常成長粒が混在するためｉＨｃ
の劣化をもたらすからである。[0013] The reason why the half-width of the particle size distribution is set to 0.2 μm or less is that if it exceeds it, the variation in grain growth during sintering becomes large and abnormally grown grains are mixed.
This is because it causes deterioration.
【００１４】さらに、本発明の所定の目的を達成するに
は、微粉砕粉の粒度分布を０．１ 〜１．５ μｍの範
囲に制御することが必要である。この理由は、 ＳｒＯ
・ｎＦｅ２Ｏ３の化学式をもつ異方性フェライト磁石粉
末は、一般に０．１ μｍ未満の超微粉末状態では超常
磁性となり、この超微粉末が多いと、磁場中での成形に
際しては、配向度を悪化させる原因となり、Ｂｒの向上
が図れず、一方、１．５ μｍを超える粗大粒子状態で
は多磁区結晶構造をとるため、この粗大粒子が多いと、
ｉＨｃの劣化の原因となるからである。[0014] Furthermore, in order to achieve the predetermined object of the present invention, it is necessary to control the particle size distribution of the finely pulverized powder to a range of 0.1 to 1.5 μm. The reason for this is that SrO
・Anisotropic ferrite magnet powder with the chemical formula nFe2O3 generally becomes superparamagnetic when it is in an ultrafine powder state of less than 0.1 μm, and if there is a large amount of this ultrafine powder, the degree of orientation will deteriorate when compacted in a magnetic field. On the other hand, coarse particles exceeding 1.5 μm have a multi-domain crystal structure, so if there are many coarse particles,
This is because it causes deterioration of iHc.
【００１５】なお、この粒度分布を０．１ 〜１．５
μｍの範囲に完全に制御することは、工業的に困難であ
ることと、０．１ μｍ以下の微細粉が適量存在すると
、却って従来技術では未だ得ることができなかったＢｒ
の向上が図れることから、本発明では、１．５ μｍ以
上の粗大粉が１体積％以下、そして０．１ μｍ以下の
微細粉が０．５ 〜２．０体積％と限定したのである。[0015] This particle size distribution is 0.1 to 1.5.
It is industrially difficult to completely control the Br within the μm range, and if a suitable amount of fine powder of 0.1 μm or less is present, it is difficult to obtain Br using conventional techniques.
Therefore, in the present invention, the amount of coarse powder of 1.5 μm or more is limited to 1% by volume or less, and the content of fine powder of 0.1 μm or less is limited to 0.5 to 2.0% by volume.
【００１６】以上説明した本発明の方法によれば、仮焼
物の微粉砕粉を、高密度化，結晶配向度の向上および単
磁区結晶の割合を高めるのに有利な微粉砕粉の粒度分布
に分級しているため、例えばＢｒが４０００Ｇ以上で、
かつｉＨｃが４０００Ｏｅ以上の高Ｂｒで、かつ高ｉＨ
ｃの異方性フェライト磁石を容易に得ることができる。According to the method of the present invention described above, the finely pulverized powder of the calcined product is transformed into a particle size distribution of the finely pulverized powder that is advantageous for increasing the density, improving the degree of crystal orientation, and increasing the proportion of single-domain crystals. Because it is classified, for example, if Br is 4000G or more,
and high Br with iHc of 4000 Oe or more, and high iH
An anisotropic ferrite magnet of c can be easily obtained.
【００１７】[0017]
【実施例】以下に、本発明を実施例により説明する。Ｆ
ｅ２Ｏ３ とＳｒＣＯ３ とを所定量配合し、この混合
粉にＳｉＯ２を０．３５ｗｔ％添加して造粒した後１３
００℃の温度で仮焼をすることにより ＳｒＯ・５．６
Ｆｅ２Ｏ３なる組成の仮焼物を得た。次いで、得られた
仮焼物をクラッシャーで粗粉砕後、アトライターで湿式
微粉砕し、乾燥させて微粉砕粉を得た。[Examples] The present invention will be explained below with reference to Examples. F
After blending a predetermined amount of e2O3 and SrCO3 and adding 0.35 wt% of SiO2 to this mixed powder and granulating it, 13
By calcining at a temperature of 00℃, SrO・5.6
A calcined product having a composition of Fe2O3 was obtained. Next, the obtained calcined product was coarsely pulverized with a crusher, wet-pulverized with an attritor, and dried to obtain a finely pulverized powder.
【００１８】この得られた粉末の粒度分布をキューリー
点以上の高温分級法およびＨＣｌ酸洗で制御し、表１お
よび２に示すような粒度分布をもつ微粉末を得た。なお
、粒度分布は電子顕微鏡による観察から求め、半値幅は
その粒度分布から求めた。The particle size distribution of the obtained powder was controlled by high temperature classification above the Curie point and HCl pickling to obtain a fine powder having a particle size distribution as shown in Tables 1 and 2. Note that the particle size distribution was determined from observation using an electron microscope, and the half width was determined from the particle size distribution.
【００１９】さらに、これらの微粉末をそれぞれスラリ
ー化し、５００ｋｇ／ｃｍ２ の圧力で、７ｋＯｅの磁
界中で湿式成形を行い、得られた成形体を１２２０℃で
焼結した結果、表１および２に示すような磁気特性を有
する異方性フェライト磁石を得た。[0019] Furthermore, each of these fine powders was made into a slurry, wet-molded in a magnetic field of 7 kOe at a pressure of 500 kg/cm2, and the resulting compact was sintered at 1220°C. An anisotropic ferrite magnet with magnetic properties as shown was obtained.
【００２０】表１および２の結果から明らかなように、
粉末の粒度分布が本発明の範囲から逸脱した比較例の場
合は、磁気特性（ＢｒおよびｉＨｃ）の劣化を招くこと
がわかる。また、試料１〜４の本発明例の場合は、いず
れもＢｒが４０００Ｇ以上で、かつｉＨｃが４０００Ｏ
ｅ以上の高Ｂｒ，高ｉＨｃの異方性フェライト磁石が得
られることがわかる。しかも、本発明例では、０．１
μｍ以下の微細粉が適量存在することにより、従来技術
では未だ得ることができなかったＢｒの向上が図れるこ
とが判った。As is clear from the results in Tables 1 and 2,
It can be seen that in the case of the comparative example in which the particle size distribution of the powder deviates from the range of the present invention, the magnetic properties (Br and iHc) deteriorate. In addition, in the case of samples 1 to 4 of the present invention, Br is 4000G or more and iHc is 4000O.
It can be seen that an anisotropic ferrite magnet with high Br and high iHc of e or more can be obtained. Moreover, in the example of the present invention, 0.1
It has been found that the presence of an appropriate amount of micron-sized fine powder makes it possible to improve Br, which has not yet been possible with conventional techniques.
【００２１】[0021]
【表１】[Table 1]
【００２２】[0022]
【表２】[Table 2]
【００２３】[0023]
【発明の効果】以上説明したように、本発明によれば、
仮焼物の微粉砕粉の好適粒度分布が明らかになり、この
ような粒度分布の仮焼物の微粉砕粉を調整することによ
って、粗大粉によるｉＨｃの劣化、あるいは微細粉によ
るＢｒおよびｉＨｃの劣化等の特性向上の阻害要因を排
除することができ、ひいては高Ｂｒかつ高ｉＨｃの異方
性酸化物永久磁石を安定して製造できる。[Effects of the Invention] As explained above, according to the present invention,
The suitable particle size distribution of the finely pulverized powder of the calcined product has been clarified, and by adjusting the finely pulverized powder of the calcined product with such a particle size distribution, it is possible to prevent the deterioration of iHc due to coarse powder or the deterioration of Br and iHc due to fine powder, etc. It is possible to eliminate the factors that inhibit the improvement of the characteristics, and as a result, it is possible to stably manufacture anisotropic oxide permanent magnets with high Br and high iHc.
【００２４】なお、本発明の方法は、Ｓｒ系フェライト
磁石のみならずＢａ系フェライト磁石等の酸化物永久磁
石にも有効に適用される。The method of the present invention can be effectively applied not only to Sr-based ferrite magnets but also to oxide permanent magnets such as Ba-based ferrite magnets.
Claims (1)
を仮焼し粉砕して得られる微粉末を磁場中で成形し、そ
の後本焼成して異方性酸化物永久磁石を製造する方法に
おいて、上記混合物をＦｅ２Ｏ３ とＳｒＯ とのモル
比が５．３ 〜６．１ になるように仮焼し、次いでそ
の仮焼物を微粉砕し、得られた微粉末を、空気透過法で
表わされる平均粒径が０．６ 〜１．０ μｍで、体積
割合で表わした粒度分布の半値幅が０．２ μｍ以下で
、１．５ μｍ以上の粗大粉が１体積％以下で、そして
０．１ μｍ以下の微細粉が０．５〜２．０ 体積％と
なるように分級調整し、その後磁場成形に付することを
特徴とする異方性酸化物永久磁石の製造方法。Claim 1. A method for manufacturing an anisotropic oxide permanent magnet by molding a fine powder obtained by calcining and pulverizing a mixture of Fe2O3 and SrCO3 in a magnetic field, and then main firing it. The calcined product is calcined so that the molar ratio of SrO and SrO is 5.3 to 6.1, and then the calcined product is finely pulverized. 6 to 1.0 μm, the half width of the particle size distribution expressed as a volume percentage is 0.2 μm or less, coarse powder of 1.5 μm or more is 1% by volume or less, and fine powder of 0.1 μm or less A method for producing an anisotropic oxide permanent magnet, which comprises classifying and adjusting the magnet so that the amount thereof is 0.5 to 2.0% by volume, and then subjecting it to magnetic field forming.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3112172A JPH04320009A (en) | 1991-04-18 | 1991-04-18 | Fabrication of anisotropic oxide permanent magnet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3112172A JPH04320009A (en) | 1991-04-18 | 1991-04-18 | Fabrication of anisotropic oxide permanent magnet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04320009A true JPH04320009A (en) | 1992-11-10 |
Family
ID=14580055
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3112172A Pending JPH04320009A (en) | 1991-04-18 | 1991-04-18 | Fabrication of anisotropic oxide permanent magnet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04320009A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007123511A (en) * | 2005-10-27 | 2007-05-17 | Tdk Corp | Ferrite sintered magnet |
| JP2019215949A (en) * | 2014-12-12 | 2019-12-19 | ソニー株式会社 | Magnetic recording medium |
-
1991
- 1991-04-18 JP JP3112172A patent/JPH04320009A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007123511A (en) * | 2005-10-27 | 2007-05-17 | Tdk Corp | Ferrite sintered magnet |
| JP4730534B2 (en) * | 2005-10-27 | 2011-07-20 | Ｔｄｋ株式会社 | Ferrite sintered magnet |
| JP2019215949A (en) * | 2014-12-12 | 2019-12-19 | ソニー株式会社 | Magnetic recording medium |
| US11355270B2 (en) | 2014-12-12 | 2022-06-07 | Sony Corporation | Magnetic powder, method for production thereof, and magnetic recording medium |
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