WO2010041645A1 - Method for producing perovskite-structure compound sintered compact - Google Patents

Method for producing perovskite-structure compound sintered compact Download PDF

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WO2010041645A1
WO2010041645A1 PCT/JP2009/067384 JP2009067384W WO2010041645A1 WO 2010041645 A1 WO2010041645 A1 WO 2010041645A1 JP 2009067384 W JP2009067384 W JP 2009067384W WO 2010041645 A1 WO2010041645 A1 WO 2010041645A1
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structure compound
single crystal
perovskite structure
powder
sintered body
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Japanese (ja)
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恭也 三輪
慎一郎 川田
雅彦 木村
達 鈴木
哲郎 打越
義雄 目
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株式会社村田製作所
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Definitions

  • the present invention relates to a method for producing a sintered body made of a compound having a perovskite structure, and particularly relates to an improvement for enhancing the crystal orientation of the sintered body.
  • ceramics having a perovskite structure such as BaTiO 3 and Pb (Zr, Ti) O 3 have been used as dielectric materials and piezoelectric materials.
  • ceramics having a perovskite structure it is known that various properties are improved by orienting the crystal.
  • TGG Temporated Grain Growth
  • TMC Topical Micro-crystal Conversion Method
  • Patent Document 1 discloses a technique for orienting ceramic polycrystalline powder in a magnetic field. More specifically, the technique described in Patent Document 1 is intended to form a ceramic slurry in a magnetic field that contains a perovskite structure compound as a main component of a dispersed phase and contains, for example, a 3d element as a subcomponent. .
  • Patent Document 1 has a problem that it costs because it includes, for example, a 3d element as a subcomponent. Further, even with the technique described in Patent Document 1, there is still room for improvement with respect to the improvement of the orientation degree, and further improvement of the orientation degree is desired.
  • an object of the present invention is to provide a method for producing a sintered body of a perovskite structure compound that can solve the above-described problems.
  • a method for producing a sintered body of a perovskite structure compound according to the present invention includes a step of preparing a single crystal powder composed of single crystal particles of a perovskite structure compound, and It comprises a step of producing a ceramic slurry containing crystal powder, a step of obtaining a ceramic molded body by molding the ceramic slurry in a magnetic field, and a step of sintering the ceramic molded body.
  • a polycrystalline powder comprising polycrystalline particles of the same perovskite structure compound as the perovskite structure compound constituting the single crystal powder.
  • the ceramic slurry includes not only a single crystal powder but also the polycrystalline powder as a dispersed phase.
  • the single crystal powder occupies 5 mol% or more of the dispersed phase in the ceramic slurry.
  • the single crystal powder occupies 90 mol% or less of the dispersed phase in the ceramic slurry.
  • the step of preparing the single crystal powder includes a step of crystal-growing the particles of the perovskite structure compound by heat treating the calcined powder of the perovskite structure compound in a flux.
  • a flux at least one of KCl and NaCl is advantageously used as the flux.
  • the perovskite structure compound is preferably composed mainly of PbTiO 3 .
  • the ceramic slurry containing the single crystal powder composed of the single crystal particles of the perovskite structure compound is molded in a magnetic field and sintered, so that even if the crystal shape anisotropy is small A sintered body having a uniform crystal orientation, that is, a high degree of orientation can be obtained.
  • the sintered body obtained by the present invention has a shape anisotropy of crystals in the sintered body as compared with a sintered body produced by a TGG method that uses crystal shape anisotropy for orientation. Since it is small, it can be made difficult to generate and develop cracks.
  • the ceramic slurry contains not only single crystal powder but also polycrystalline powder as a dispersed phase
  • the polycrystalline powder can be obtained at a lower cost than the single crystal powder.
  • the cost for implementing the manufacturing method of the sintered compact which concerns on this can be reduced, and it can be excellent in practicality.
  • the effect of improving the orientation by the single crystal powder can be reliably achieved.
  • the XRD charts of the sintered bodies according to each of Samples 1, 2, and 3 prepared in the experimental example are shown in the upper sections of (a), (b), and (c), respectively, and (a), (b) And in each lower stage of (c), there is an XRD chart of each sintered body obtained by firing a ceramic molded body molded without applying a magnetic field while using the ceramic slurry according to each of Samples 1, 2, and 3.
  • FIG. It is a figure which shows the SEM image of the surface of the sintered compact concerning the sample 1 produced in the experiment example.
  • the present invention is directed to a method for producing a sintered body of a perovskite structure compound such as a sintered body mainly composed of PbTiO 3 .
  • a single crystal powder composed of single crystal particles of a perovskite structure compound is produced. Therefore, a calcined powder of the perovskite structure compound is prepared, and this calcined powder is heat-treated in the flux. As a result, the particles of the perovskite structure compound grow, and a single crystal powder composed of the single crystal particles of the perovskite structure compound is obtained.
  • at least one of KCl and NaCl is advantageously used as the flux.
  • a polycrystalline powder composed of polycrystalline particles of the same perovskite structure compound as the perovskite structure compound constituting the single crystal powder is further prepared.
  • the single crystal powder preferably occupies 5 mol% or more of the dispersed phase in the ceramic slurry.
  • the dispersed phase includes both single crystal powder and polycrystalline powder.
  • the single crystal powder preferably accounts for 90 mol% or less of the dispersed phase, and more preferably accounts for 50 mol% or less.
  • the ceramic slurry is formed in a magnetic field, whereby a ceramic formed body is obtained.
  • the crystal axes of the single crystal particles constituting the single crystal powder are oriented so as to face a predetermined direction in accordance with the applied magnetic field.
  • the ceramic molded body is fired. Thereby, a sintered body having a high degree of orientation is obtained.
  • Sample preparation [Sample 1] Sample 1 is within the scope of the present invention, and in producing a ceramic slurry, only a single crystal powder is used as a dispersed phase.
  • FIG. 1 shows an SEM image of the PbTiO 3 calcined product.
  • the calcined product was dry pulverized and mixed with KCl so as to have a weight ratio of 1: 1.
  • This at an alumina crucible, and 12 hours heat treatment at 1000 ° C., after cooling to room temperature, dissolved and removed KCl with water, dried, crystallized grown PbTiO 3 PbTiO 3 single constituted by a single crystal grain Crystal powder was obtained.
  • Figure 2 shows the SEM images of PbTiO 3 single crystal particles constituting the PbTiO 3 single crystal powder
  • Figure 3 shows a TEM image of the PbTiO 3 single crystal grains
  • FIG. 4 the same PbTiO 3 single crystal grains An electron diffraction image is shown.
  • the ceramic slurry was cast and molded in a magnetic field of 12T to obtain a ceramic molded body.
  • the sintered compact which concerns on the sample 1 was obtained by baking this ceramic molded object at the temperature of 1200 degreeC.
  • Sample 2 is within the scope of the present invention, and uses both single crystal powder and polycrystalline powder as the dispersed phase when preparing the ceramic slurry.
  • FIG. 5 shows an SEM image of the PbTiO 3 calcined product.
  • PbTiO 3 calcined product shown in Figure 5 since the calcination temperature is lower than the PbTiO 3 calcined product shown in FIG. 1, folded crystals sufficiently grown It can be seen that this is a PbTiO 3 polycrystalline powder composed of PbTiO 3 polycrystalline particles.
  • the ceramic slurry was cast and molded in a magnetic field of 12T to obtain a ceramic molded body.
  • the sintered compact which concerns on the sample 2 was obtained by baking this ceramic molded object at the temperature of 1200 degreeC.
  • Sample 3 is outside the scope of the present invention and uses only polycrystalline powder as a dispersed phase when preparing a ceramic slurry.
  • the ceramic slurry was cast and molded in a magnetic field of 12T to obtain a ceramic molded body.
  • the sintered compact which concerns on the sample 3 was obtained by baking this ceramic molded object at the temperature of 1200 degreeC.
  • sample 1 As shown in the upper part of FIG. 6A, only the peak in the ⁇ 100> direction is observed, and it can be seen that the degree of orientation is almost 100%.
  • sample 3 the upper pattern in FIG. 6C is almost the same as the lower pattern, and it can be seen that the sample is not oriented.
  • the degree of orientation of the sintered body according to each sample obtained was calculated based on the following formula (1) by the Lotgering method.
  • a sintered body having the same composition obtained by firing a ceramic molded body molded without applying a magnetic field was used as a comparative sample.
  • ⁇ I (HKL) is the sum of X-ray peak intensities of specific crystal planes (HKL) in the ceramic sintered body to be evaluated
  • ⁇ I (hkl) is the total crystal plane of the ceramic sintered body to be evaluated ( hkl) is the sum of the X-ray peak intensities.
  • ⁇ Io (HKL) is the sum of X-ray peak intensities of specific crystal planes (HKL) of the comparative sample
  • ⁇ Io (hkl) is the X-ray peak intensities of all crystal planes (hkl) of the comparative sample. Is the sum of
  • Table 1 shows the degree of orientation of the sintered bodies according to Samples 1 to 3 thus obtained.
  • Samples 1 and 2 have a high degree of orientation, and Sample 1 in particular has a very high degree of orientation of 99%.
  • the degree of orientation is 0%, indicating that the sample is not oriented.
  • FIG. 7 shows an SEM image of the surface of the sintered body according to Sample 1. From FIG. 7, it can be seen that in the sintered body according to Sample 1, crystal grains are isotropically grown and the shape anisotropy is small. In general, in order to increase the degree of orientation of the sintered body, it is necessary to apply a TGG method or the like. Although there is a problem, according to the sintered body according to sample 1, as described above, since the shape anisotropy is small, cracks are hardly generated or propagated, and a sintered body having high strength can be obtained.

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Abstract

Provided is a method for producing a sintered compact of a perovskite-structure compound having a high degree of orientation, comprising a step for preparing a monocrystalline powder formed from monocrystalline particles of a perovskite-structure compound; a step for producing a ceramic slurry containing said monocrystalline powder as the dispersion phase; a step for obtaining a ceramic molded article by molding the ceramic slurry in a magnetic field; and a step for sintering the ceramic molded article. Preferably a multicrystalline powder formed from multicrystalline particles of the same perovskite-structure compound as the perovskite-structure compound that forms the monocrystalline powder is prepared such that the ceramic slurry contains not only monocrystalline particles, but also multicrystalline particles, as the dispersion phase.  　

Description

ペロブスカイト構造化合物の焼結体の製造方法Method for producing sintered body of perovskite structure compound
　この発明は、ペロブスカイト構造を有する化合物からなる焼結体の製造方法に関するもので、特に、焼結体の結晶配向性を高めるための改良に関するものである。 The present invention relates to a method for producing a sintered body made of a compound having a perovskite structure, and particularly relates to an improvement for enhancing the crystal orientation of the sintered body.
　従来から、誘電体材料や圧電体材料として、ＢａＴｉＯ３やＰｂ(Ｚｒ、Ｔｉ)Ｏ３などのペロブスカイト構造を有するセラミックが使用されている。これらのペロブスカイト構造のセラミックにおいては、その結晶を配向させることによって、諸特性が向上することが知られている。 Conventionally, ceramics having a perovskite structure such as BaTiO 3 and Pb (Zr, Ti) O 3 have been used as dielectric materials and piezoelectric materials. In these ceramics having a perovskite structure, it is known that various properties are improved by orienting the crystal.
　高い結晶配向性を得るため、たとえばＢｉ層状化合物の場合には、ＴＧＧ（Templated Grain Growth）法が適用されるが、ペロブスカイト構造化合物の場合には、結晶の形状異方性が小さいため、ＴＧＧ法にて配向するには、ＴＭＣ法(Topochemical Micro-crystal Conversion Method)などのコスト高なプロセスを導入する必要がある。 In order to obtain high crystal orientation, for example, a TGG (Templated Grain Growth) method is applied in the case of a Bi layered compound, but in the case of a perovskite structure compound, since the crystal shape anisotropy is small, the TGG method is used. It is necessary to introduce a costly process such as a TMC method (Topochemical Micro-crystal Conversion Method) in order to orient the film.
　一方、タングステンブロンズ化合物の場合には、結晶の形状異方性が小さくても、結晶異方性が大きい（結晶軸によって磁化率の差が大きい）ので、磁場中成形を用いることにより、高配向の焼結体が得られる。しかし、ペロブスカイト構造化合物の場合には、結晶異方性が小さいので、一般的には、磁場中成形によって、高配向にすることが困難である。 On the other hand, in the case of a tungsten bronze compound, even if the crystal shape anisotropy is small, the crystal anisotropy is large (the difference in magnetic susceptibility is large depending on the crystal axis). Thus obtained sintered body is obtained. However, in the case of a perovskite structure compound, since the crystal anisotropy is small, it is generally difficult to achieve high orientation by molding in a magnetic field.
　そこで、ペロブスカイト構造化合物に適用され得る磁場中成形技術として、特開２００８－３７０６４号公報（特許文献１）に記載されたものが注目される。特許文献１には、セラミックの多結晶粉末を磁場中で配向させる技術が開示されている。より具体的には、特許文献１に記載の技術は、分散相の主成分としてペロブスカイト構造化合物を含み、かつ副成分としてたとえば３ｄ元素を含む、セラミックスラリーを磁場中で成形しようとするものである。 Therefore, as a molding technique in a magnetic field that can be applied to a perovskite structure compound, the one described in Japanese Patent Application Laid-Open No. 2008-37064 (Patent Document 1) is noted. Patent Document 1 discloses a technique for orienting ceramic polycrystalline powder in a magnetic field. More specifically, the technique described in Patent Document 1 is intended to form a ceramic slurry in a magnetic field that contains a perovskite structure compound as a main component of a dispersed phase and contains, for example, a 3d element as a subcomponent. .
　しかしながら、特許文献１に記載の技術には、副成分としてたとえば３ｄ元素を含むため、コストがかかるという問題がある。また、特許文献１に記載の技術によっても、配向度の向上に関して、なおも改善の余地があり、さらなる配向度の向上が望まれるところである。 However, the technique described in Patent Document 1 has a problem that it costs because it includes, for example, a 3d element as a subcomponent. Further, even with the technique described in Patent Document 1, there is still room for improvement with respect to the improvement of the orientation degree, and further improvement of the orientation degree is desired.
特開２００８－３７０６４号公報JP 2008-37064 A
　そこで、この発明の目的は、上述したような課題を解決し得る、ペロブスカイト構造化合物の焼結体の製造方法を提供しようとすることである。 Therefore, an object of the present invention is to provide a method for producing a sintered body of a perovskite structure compound that can solve the above-described problems.
　この発明に係るペロブスカイト構造化合物の焼結体の製造方法は、上述した技術的課題を解決するため、ペロブスカイト構造化合物の単結晶粒子からなる単結晶粉末を用意する工程と、分散相として、上記単結晶粉末を含む、セラミックスラリーを作製する工程と、セラミックスラリーを磁場中で成形することによって、セラミック成形体を得る工程と、セラミック成形体を焼結させる工程とを備えることを特徴としている。 In order to solve the technical problem described above, a method for producing a sintered body of a perovskite structure compound according to the present invention includes a step of preparing a single crystal powder composed of single crystal particles of a perovskite structure compound, and It comprises a step of producing a ceramic slurry containing crystal powder, a step of obtaining a ceramic molded body by molding the ceramic slurry in a magnetic field, and a step of sintering the ceramic molded body.
　この発明に係るペロブスカイト構造化合物の焼結体の製造方法を実施するにあたり、より実用的な局面では、上記単結晶粉末を構成するペロブスカイト構造化合物と同じペロブスカイト構造化合物の多結晶粒子からなる多結晶粉末がさらに用意され、セラミックスラリーは、分散相として、単結晶粉末だけでなく、上記多結晶粉末をも含むようにされる。 In carrying out the method for producing a sintered body of a perovskite structure compound according to the present invention, in a more practical aspect, a polycrystalline powder comprising polycrystalline particles of the same perovskite structure compound as the perovskite structure compound constituting the single crystal powder. Is prepared, and the ceramic slurry includes not only a single crystal powder but also the polycrystalline powder as a dispersed phase.
　上述した実施態様において、単結晶粉末は、セラミックスラリーにおける分散相の５モル％以上を占めるようにされることが好ましい。 In the embodiment described above, it is preferable that the single crystal powder occupies 5 mol% or more of the dispersed phase in the ceramic slurry.
　また、単結晶粉末は、セラミックスラリーにおける分散相の９０モル％以下を占めるようにされることが好ましい。 Moreover, it is preferable that the single crystal powder occupies 90 mol% or less of the dispersed phase in the ceramic slurry.
　この発明において、単結晶粉末を用意する工程は、ペロブスカイト構造化合物の仮焼粉末をフラックス中で熱処理することによって、ペロブスカイト構造化合物の粒子を結晶成長させる工程を備えることが好ましい。この場合、フラックスとして、ＫＣｌおよびＮａＣｌの少なくとも一方が有利に用いられる。 In this invention, it is preferable that the step of preparing the single crystal powder includes a step of crystal-growing the particles of the perovskite structure compound by heat treating the calcined powder of the perovskite structure compound in a flux. In this case, at least one of KCl and NaCl is advantageously used as the flux.
　また、ペロブスカイト構造化合物は、好ましくは、ＰｂＴｉＯ３を主成分とするものである。 The perovskite structure compound is preferably composed mainly of PbTiO 3 .
　この発明によれば、ペロブスカイト構造化合物の単結晶粒子からなる単結晶粉末を含むセラミックスラリーを磁場中で成形し、これを焼結するようにしているので、結晶の形状異方性が小さくても、結晶方向が揃った、すなわち配向度が高い焼結体を得ることができる。 According to the present invention, the ceramic slurry containing the single crystal powder composed of the single crystal particles of the perovskite structure compound is molded in a magnetic field and sintered, so that even if the crystal shape anisotropy is small A sintered body having a uniform crystal orientation, that is, a high degree of orientation can be obtained.
　この理由は、次のように推測することができる。通常の仮焼粉末では、粒子が多結晶で構成されているため、磁場が粒子を回転させるモーメントが全体として打ち消し合ってしまうが、単結晶からなる粒子は結晶軸が揃っているため、粒子を回転させるモーメントが打ち消し合うことがなく、このため、結晶異方性の小さなペロブスカイト構造化合物でも高い配向度が得られるものと推測することができる。 This reason can be guessed as follows. In normal calcined powder, since the particles are composed of polycrystals, the moment that the magnetic field rotates the particles cancels out as a whole. Since the rotating moments do not cancel each other, it can be assumed that a high degree of orientation can be obtained even with a perovskite structure compound having a small crystal anisotropy.
　また、この発明によって得られた焼結体は、結晶の形状異方性を利用して配向させるＴＧＧ法などで作製した焼結体と比較し、焼結体中の結晶の形状異方性が小さいため、クラックの発生や進展を生じさせにくくすることができる。 In addition, the sintered body obtained by the present invention has a shape anisotropy of crystals in the sintered body as compared with a sintered body produced by a TGG method that uses crystal shape anisotropy for orientation. Since it is small, it can be made difficult to generate and develop cracks.
　この発明において、セラミックスラリーが、分散相として、単結晶粉末だけでなく、多結晶粉末をも含むようにされると、多結晶粉末は単結晶粉末より低コストで得ることができるので、この発明に係る焼結体の製造方法を実施するためのコストを低減することができ、実用性に優れたものとすることができる。 In this invention, if the ceramic slurry contains not only single crystal powder but also polycrystalline powder as a dispersed phase, the polycrystalline powder can be obtained at a lower cost than the single crystal powder. The cost for implementing the manufacturing method of the sintered compact which concerns on this can be reduced, and it can be excellent in practicality.
　上述した実施態様において、単結晶粉末が分散相の５モル％以上を占めるようにされると、単結晶粉末による配向性向上の効果を確実に達成することができる。 In the embodiment described above, when the single crystal powder occupies 5 mol% or more of the dispersed phase, the effect of improving the orientation by the single crystal powder can be reliably achieved.
実験例において、試料１を作製するために用いられたＰｂＴｉＯ３仮焼物のＳＥＭ像を示す図である。In experimental examples, it is a view showing an SEM image of PbTiO 3 calcined product was used to prepare a sample 1. 実験例において、試料１を作製するため、図１に示したＰｂＴｉＯ３仮焼物を結晶成長させて得られたＰｂＴｉＯ３単結晶粒子のＳＥＭ像を示す図である。In Experimental Examples, to prepare a sample 1, is a view showing an SEM image of the obtained PbTiO 3 single crystal particles by crystal growth PbTiO 3 calcined product shown in FIG. 図２に示したＰｂＴｉＯ３単結晶粒子のＴＥＭ像を示す図である。PbTiO shown in FIG. 2 3 is a view showing a TEM image of single-crystal particles. 図２に示したＰｂＴｉＯ３単結晶粒子の電子線回折像を示す図である。FIG. 3 is a diagram showing an electron beam diffraction image of the PbTiO 3 single crystal particle shown in FIG. 2. 実験例において、試料２および３を作製するために用いられたＰｂＴｉＯ３仮焼物のＳＥＭ像を示す図である。In experimental examples, it is a view showing an SEM image of PbTiO 3 calcined product used to make Samples 2 and 3. 実験例において作製した試料１、２および３の各々に係る焼結体のＸＲＤチャートを、それぞれ、（ａ）、（ｂ）および（ｃ）の各上段に示すとともに、（ａ）、（ｂ）および（ｃ）の各下段に、試料１、２および３の各々に係るセラミックスラリーを用いながら、磁場を印加しないで成形したセラミック成形体を焼成して得られた各焼結体のＸＲＤチャートが示す図である。The XRD charts of the sintered bodies according to each of Samples 1, 2, and 3 prepared in the experimental example are shown in the upper sections of (a), (b), and (c), respectively, and (a), (b) And in each lower stage of (c), there is an XRD chart of each sintered body obtained by firing a ceramic molded body molded without applying a magnetic field while using the ceramic slurry according to each of Samples 1, 2, and 3. FIG. 実験例において作製した試料１に係る焼結体の表面のＳＥＭ像を示す図である。It is a figure which shows the SEM image of the surface of the sintered compact concerning the sample 1 produced in the experiment example.
　この発明は、たとえばＰｂＴｉＯ３を主成分とする焼結体のようなペロブスカイト構造化合物の焼結体を製造する方法に向けられる。 The present invention is directed to a method for producing a sintered body of a perovskite structure compound such as a sintered body mainly composed of PbTiO 3 .
　この発明に従ってペロブスカイト構造化合物の焼結体を製造するため、まず、ペロブスカイト構造化合物の単結晶粒子からなる単結晶粉末が作製される。そのため、ペロブスカイト構造化合物の仮焼粉末が用意され、この仮焼粉末がフラックス中で熱処理される。これによって、ペロブスカイト構造化合物の粒子が結晶成長し、ペロブスカイト構造化合物の単結晶粒子からなる単結晶粉末が得られる。ここで、フラックスとして、ＫＣｌおよびＮａＣｌの少なくとも一方が有利に用いられる。 In order to produce a sintered body of a perovskite structure compound according to the present invention, first, a single crystal powder composed of single crystal particles of a perovskite structure compound is produced. Therefore, a calcined powder of the perovskite structure compound is prepared, and this calcined powder is heat-treated in the flux. As a result, the particles of the perovskite structure compound grow, and a single crystal powder composed of the single crystal particles of the perovskite structure compound is obtained. Here, at least one of KCl and NaCl is advantageously used as the flux.
　他方、上記単結晶粉末を構成するペロブスカイト構造化合物と同じペロブスカイト構造化合物の多結晶粒子からなる多結晶粉末がさらに用意される。 On the other hand, a polycrystalline powder composed of polycrystalline particles of the same perovskite structure compound as the perovskite structure compound constituting the single crystal powder is further prepared.
　次に、分散相として、上記単結晶粉末および上記多結晶粉末の双方を含む、セラミックスラリーが作製される。ここで、単結晶粉末による配向度向上の効果をより確実に達成できるようにするため、単結晶粉末は、セラミックスラリーにおける分散相の５モル％以上を占めるようにされることが好ましい。 Next, a ceramic slurry containing both the single crystal powder and the polycrystalline powder as a dispersed phase is prepared. Here, in order to more reliably achieve the effect of improving the degree of orientation by the single crystal powder, the single crystal powder preferably occupies 5 mol% or more of the dispersed phase in the ceramic slurry.
　なお、セラミックスラリーにおける分散相として、多結晶粉末を用いずに、単結晶粉末だけを用いてもよい。単結晶粉末だけを用いる方が配向度をより向上させることができる。しかしながら、単結晶粉末を得るためのコストは多結晶粉末を得るためのコストより高いため、実用的には、分散相は単結晶粉末および多結晶粉末の双方を含むようにされる。コストの観点からは、単結晶粉末は、分散相の９０モル％以下を占めるようにされることが好ましく、５０モル％以下を占めるようにされることがより好ましい。 In addition, you may use only a single crystal powder as a dispersed phase in a ceramic slurry, without using a polycrystalline powder. The orientation degree can be further improved by using only the single crystal powder. However, since the cost for obtaining a single crystal powder is higher than the cost for obtaining a polycrystalline powder, in practice, the dispersed phase includes both single crystal powder and polycrystalline powder. From the viewpoint of cost, the single crystal powder preferably accounts for 90 mol% or less of the dispersed phase, and more preferably accounts for 50 mol% or less.
　次に、上記セラミックスラリーが磁場中で成形され、それによって、セラミック成形体が得られる。この工程において、単結晶粉末を構成する単結晶粒子の結晶軸が、付与された磁場に従って所定の方向に向くように配向される。 Next, the ceramic slurry is formed in a magnetic field, whereby a ceramic formed body is obtained. In this step, the crystal axes of the single crystal particles constituting the single crystal powder are oriented so as to face a predetermined direction in accordance with the applied magnetic field.
　次に、セラミック成形体が焼成される。これによって、高い配向度を有する焼結体が得られる。 Next, the ceramic molded body is fired. Thereby, a sintered body having a high degree of orientation is obtained.
　次に、この発明による効果を確認するために実施した実験例について説明する。 Next, experimental examples carried out to confirm the effects of the present invention will be described.
　１．試料の作製
　［試料１］
　試料１は、この発明の範囲内のもので、セラミックスラリーを作製するにあたって、分散相として、単結晶粉末のみを用いたものである。 1. Sample preparation [Sample 1]
Sample 1 is within the scope of the present invention, and in producing a ceramic slurry, only a single crystal powder is used as a dispersed phase.
　ＰｂＯおよびＴｉＯ２の各粉末をＰｂ：Ｔｉのモル比が１：１となるように秤量し、これらをボールミルにて１５時間湿式混合した後、１１００℃にて仮焼乾燥し、ＰｂＴｉＯ３仮焼物を得た。図１は、このＰｂＴｉＯ３仮焼物のＳＥＭ像を示している。 Each powder of PbO and TiO 2 was weighed so that the molar ratio of Pb: Ti was 1: 1, and these were wet mixed in a ball mill for 15 hours, then calcined and dried at 1100 ° C., and PbTiO 3 calcined product Got. FIG. 1 shows an SEM image of the PbTiO 3 calcined product.
　次に、上記仮焼物を乾式粉砕し、ＫＣｌと重量比で１：１となるように混合した。これをアルミナるつぼ中で、１０００℃にて１２時間熱処理し、室温まで冷却した後、水でＫＣｌを溶解・除去し、乾燥させて、結晶成長したＰｂＴｉＯ３単結晶粒子で構成されたＰｂＴｉＯ３単結晶粉末を得た。図２は、ＰｂＴｉＯ３単結晶粉末を構成するＰｂＴｉＯ３単結晶粒子のＳＥＭ像を示し、図３は、同ＰｂＴｉＯ３単結晶粒子のＴＥＭ像を示し、図４は、同ＰｂＴｉＯ３単結晶粒子の電子線回折像を示している。 Next, the calcined product was dry pulverized and mixed with KCl so as to have a weight ratio of 1: 1. This at an alumina crucible, and 12 hours heat treatment at 1000 ° C., after cooling to room temperature, dissolved and removed KCl with water, dried, crystallized grown PbTiO 3 PbTiO 3 single constituted by a single crystal grain Crystal powder was obtained. Figure 2 shows the SEM images of PbTiO 3 single crystal particles constituting the PbTiO 3 single crystal powder, Figure 3 shows a TEM image of the PbTiO 3 single crystal grains, FIG. 4, the same PbTiO 3 single crystal grains An electron diffraction image is shown.
　図２に示すように、ＰｂＴｉＯ３単結晶粒子において、立方体形状の結晶が成長しており、結晶形状が揃っている。図３から、直方体形状の望ましい粒子が得られていることがわかる。図４に示すように、ＰｂＴｉＯ３単結晶粒子中の数点について電子線回折像を測定したところ、スポットが直線に沿って形成されていることから、粒子が単結晶からなっており、また結晶軸も揃っていることがわかる。 As shown in FIG. 2, in the PbTiO 3 single crystal particles, cubic crystals are grown and the crystal shapes are uniform. It can be seen from FIG. 3 that desirable rectangular parallelepiped particles are obtained. As shown in FIG. 4, when the electron diffraction image was measured at several points in the PbTiO 3 single crystal particle, since the spots were formed along a straight line, the particle was made of a single crystal, and the crystal You can see that the axes are aligned.
　次に、上記のようにして得られた結晶成長したＰｂＴｉＯ３単結晶粒子を３０ｇ取り出し、このＰｂＴｉＯ３単結晶粒子１００重量部に対し、０．５重量部のポリビニルアルコールおよび４０重量部の純水を加えて、ボールミルにて１２時間混合することによって、セラミックスラリーを得た。 Next, 30 g of the crystal-grown PbTiO 3 single crystal particles obtained as described above were taken out, and 0.5 parts by weight of polyvinyl alcohol and 40 parts by weight of pure water with respect to 100 parts by weight of the PbTiO 3 single crystal particles. Was added and mixed with a ball mill for 12 hours to obtain a ceramic slurry.
　次に、上記セラミックスラリーを１２Ｔの磁場中で鋳込み成形することにより、セラミック成形体を得た。そして、このセラミック成形体を１２００℃の温度で焼成することにより、試料１に係る焼結体を得た。 Next, the ceramic slurry was cast and molded in a magnetic field of 12T to obtain a ceramic molded body. And the sintered compact which concerns on the sample 1 was obtained by baking this ceramic molded object at the temperature of 1200 degreeC.
　［試料２］
　試料２は、この発明の範囲内のもので、セラミックスラリーを作製するにあたって、分散相として、単結晶粉末および多結晶粉末の双方を用いたものである。 [Sample 2]
Sample 2 is within the scope of the present invention, and uses both single crystal powder and polycrystalline powder as the dispersed phase when preparing the ceramic slurry.
　試料１の場合と同様にして、結晶成長したＰｂＴｉＯ３単結晶粒子で構成されたＰｂＴｉＯ３単結晶粉末を得た。 In the same manner as in the case of Sample 1, a PbTiO 3 single crystal powder composed of crystal-grown PbTiO 3 single crystal particles was obtained.
　他方、ＰｂＯおよびＴｉＯ２の各粉末をＰｂ：Ｔｉのモル比が１：１となるように秤量し、これらをボールミルにて１５時間湿式混合した後、９００℃にて仮焼乾燥し、ＰｂＴｉＯ３仮焼物を得た。図５は、このＰｂＴｉＯ３仮焼物のＳＥＭ像を示している。図５と前述の図１とを比較すれば、図５に示したＰｂＴｉＯ３仮焼物は、図１に示したＰｂＴｉＯ３仮焼物に比べて仮焼温度が低いため、結晶が十分成長しておらず、ＰｂＴｉＯ３多結晶粒子で構成されたＰｂＴｉＯ３多結晶粉末であることがわかる。 On the other hand, each powder of PbO and TiO 2 was weighed so that the molar ratio of Pb: Ti was 1: 1, and these were wet mixed in a ball mill for 15 hours, then calcined and dried at 900 ° C., and PbTiO 3 A calcined product was obtained. FIG. 5 shows an SEM image of the PbTiO 3 calcined product. In comparison Figure 5 with the FIG. 1 described above, PbTiO 3 calcined product shown in Figure 5, since the calcination temperature is lower than the PbTiO 3 calcined product shown in FIG. 1, folded crystals sufficiently grown It can be seen that this is a PbTiO 3 polycrystalline powder composed of PbTiO 3 polycrystalline particles.
　次に、上記ＰｂＴｉＯ３単結晶粉末を５ｇ、および上記ＰｂＴｉＯ３多結晶粉末を４５ｇそれぞれ取り出し、これらＰｂＴｉＯ３単結晶粉末およびＰｂＴｉＯ３多結晶粉末の合計１００重量部に対して、０．５重量部のポリビニルアルコールおよび４０重量部の純水を加えて、ボールミルにて１２時間混合することによって、セラミックスラリーを得た。 Next, the PbTiO 3 single crystal powder 5g, and the PbTiO 3 polycrystalline powder extraction 45g respectively, per 100 parts by weight of PbTiO 3 single crystal powder and PbTiO 3 polycrystalline powder, 0.5 part by weight Of polyvinyl alcohol and 40 parts by weight of pure water were added and mixed in a ball mill for 12 hours to obtain a ceramic slurry.
　なお、上記のように作製したセラミックスラリーに含まれる分散相をＴＥＭで評価した結果、ＰｂＴｉＯ３単結晶粉末が分散相中５モル％含まれていることがわかった。このように、ＰｂＴｉＯ３単結晶粉末が、混合前では１０モル％であったにも関わらず、混合後において５モル％に減少したのは、混合処理時に結晶が砕けてしまったためであると考えられる。 In addition, as a result of evaluating the disperse phase contained in the ceramic slurry produced as described above by TEM, it was found that 5 mol% of PbTiO 3 single crystal powder was contained in the disperse phase. Thus, PbTiO 3 single crystal powder, despite was 10 mol% in the premix, was decreased to 5 mol% after mixing is believed that during the mixing process because the crystals had crumbled It is done.
　次に、上記セラミックスラリーを１２Ｔの磁場中で鋳込み成形することにより、セラミック成形体を得た。そして、このセラミック成形体を１２００℃の温度で焼成することにより、試料２に係る焼結体を得た。 Next, the ceramic slurry was cast and molded in a magnetic field of 12T to obtain a ceramic molded body. And the sintered compact which concerns on the sample 2 was obtained by baking this ceramic molded object at the temperature of 1200 degreeC.
　［試料３］
　試料３は、この発明の範囲外のもので、セラミックスラリーを作製するにあたって、分散相として、多結晶粉末のみを用いたものである。 [Sample 3]
Sample 3 is outside the scope of the present invention and uses only polycrystalline powder as a dispersed phase when preparing a ceramic slurry.
　試料２の作製に用いたＰｂＴｉＯ３多結晶粒子で構成されたＰｂＴｉＯ３多結晶粉末を３０ｇ取り出し、このＰｂＴｉＯ３多結晶粒子１００重量部に対し、０．５重量部のポリビニルアルコールおよび４０重量部の純水を加えて、ボールミルにて１２時間混合することによって、セラミックスラリーを得た。 30 g of PbTiO 3 polycrystalline powder composed of the PbTiO 3 polycrystalline particles used for the preparation of Sample 2 was taken out, and 0.5 parts by weight of polyvinyl alcohol and 40 parts by weight of 100 parts by weight of the PbTiO 3 polycrystalline particles. Pure water was added and mixed with a ball mill for 12 hours to obtain a ceramic slurry.
　次に、上記セラミックスラリーを１２Ｔの磁場中で鋳込み成形することにより、セラミック成形体を得た。そして、このセラミック成形体を１２００℃の温度で焼成することにより、試料３に係る焼結体を得た。 Next, the ceramic slurry was cast and molded in a magnetic field of 12T to obtain a ceramic molded body. And the sintered compact which concerns on the sample 3 was obtained by baking this ceramic molded object at the temperature of 1200 degreeC.
　２．評価
　上記のように得られた試料１、２および３の各々に係る焼結体のＸＲＤチャートが、それぞれ、図６（ａ）、（ｂ）および（ｃ）の各上段に示されている。なお、図６（ａ）、（ｂ）および（ｃ）の各下段には、試料１、２および３の各々に係るセラミックスラリーを用いながら、磁場を印加しないで成形したセラミック成形体を焼成して得られた各焼結体のＸＲＤチャートが示されている。 2. Evaluation XRD charts of the sintered bodies according to each of Samples 1, 2, and 3 obtained as described above are shown in the upper stages of FIGS. 6 (a), (b), and (c), respectively. In each of the lower stages of FIGS. 6A, 6B and 6C, a ceramic molded body formed without applying a magnetic field is fired while using the ceramic slurry according to each of Samples 1, 2, and 3. An XRD chart of each sintered body obtained in this manner is shown.
　試料１によれば、図６（ａ）の上段に示すように、＜１００＞方向のピークのみが観察され、配向度がほぼ１００％であることがわかる。 According to sample 1, as shown in the upper part of FIG. 6A, only the peak in the <100> direction is observed, and it can be seen that the degree of orientation is almost 100%.
　次に、試料２によれば、図６（ｂ）の上段に示すように、＜１００＞方向のピークが高く、＜１００＞方向に配向していることがわかる。 Next, according to the sample 2, as shown in the upper part of FIG. 6B, it can be seen that the peak in the <100> direction is high and oriented in the <100> direction.
　これらに対して、試料３では、図６（ｃ）の上段のパターンが同下段のパターンとほぼ同じであり、配向していないことがわかる。 On the other hand, in sample 3, the upper pattern in FIG. 6C is almost the same as the lower pattern, and it can be seen that the sample is not oriented.
　次に、得られた各試料に係る焼結体の配向度を、Lotgering法により、以下の数式（１）に基づいて算出した。配向度の計算では、磁場を印加しないで成形したセラミック成形体を焼成して得られた同組成の焼結体を比較用試料とした。 Next, the degree of orientation of the sintered body according to each sample obtained was calculated based on the following formula (1) by the Lotgering method. In the calculation of the degree of orientation, a sintered body having the same composition obtained by firing a ceramic molded body molded without applying a magnetic field was used as a comparative sample.
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
　ここで、ΣＩ（ＨＫＬ）は評価対象のセラミック焼結体における特定の結晶面（ＨＫＬ）のＸ線ピーク強度の総和であり、ΣＩ（ｈｋｌ）は評価対象のセラミック焼結体の全結晶面（ｈｋｌ）のＸ線ピーク強度の総和である。 Here, ΣI (HKL) is the sum of X-ray peak intensities of specific crystal planes (HKL) in the ceramic sintered body to be evaluated, and ΣI (hkl) is the total crystal plane of the ceramic sintered body to be evaluated ( hkl) is the sum of the X-ray peak intensities.
　また、ΣＩｏ（ＨＫＬ）は上記比較用試料の特定の結晶面（ＨＫＬ）のＸ線ピーク強度の総和であり、ΣＩｏ（ｈｋｌ）は上記比較用試料の全結晶面（ｈｋｌ）のＸ線ピーク強度の総和である。 ΣIo (HKL) is the sum of X-ray peak intensities of specific crystal planes (HKL) of the comparative sample, and ΣIo (hkl) is the X-ray peak intensities of all crystal planes (hkl) of the comparative sample. Is the sum of
　測定条件は、２θ＝２０～６０ｄｅｇとした。また、全結晶面（ｈｋｌ）のＸ線ピーク強度として、＜００１＞、＜０１１＞、＜１１１＞、＜００２＞、＜１０２＞および＜１１２＞の各強度を使用した。特定の結晶面（ＨＫＬ）として、＜００１＞および＜００２＞の各強度を使用した。 Measurement conditions were 2θ = 20 to 60 deg. Moreover, each intensity | strength of <001>, <011>, <111>, <002>, <102>, and <112> was used as a X-ray peak intensity of all the crystal planes (hkl). As specific crystal planes (HKL), strengths of <001> and <002> were used.
　このようにして求められた試料１～３に係る焼結体の配向度が表１に示されている。 Table 1 shows the degree of orientation of the sintered bodies according to Samples 1 to 3 thus obtained.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表１からわかるように、試料１および２によれば、高い配向度が得られ、特に試料１では、９９％といった極めて高い配向度が得られている。これらに対して、試料３では、配向度が０％であり、配向していないことがわかる。 As can be seen from Table 1, Samples 1 and 2 have a high degree of orientation, and Sample 1 in particular has a very high degree of orientation of 99%. On the other hand, in sample 3, the degree of orientation is 0%, indicating that the sample is not oriented.
　図７には、試料１に係る焼結体の表面のＳＥＭ像が示されている。図７から、試料１に係る焼結体では、結晶粒が等方的に成長しており、形状異方性が小さいことがわかる。一般的に、焼結体の配向度を上げるためには、ＴＧＧ法等を適用する必要があるが、その場合には、形状異方性が大きく、クラックが進展しやすく、強度が得られない問題があるが、試料１に係る焼結体によれば、上述のように、形状異方性が小さいため、クラックが発生あるいは進展しにくく、強度の高い焼結体が得られることになる。 FIG. 7 shows an SEM image of the surface of the sintered body according to Sample 1. From FIG. 7, it can be seen that in the sintered body according to Sample 1, crystal grains are isotropically grown and the shape anisotropy is small. In general, in order to increase the degree of orientation of the sintered body, it is necessary to apply a TGG method or the like. Although there is a problem, according to the sintered body according to sample 1, as described above, since the shape anisotropy is small, cracks are hardly generated or propagated, and a sintered body having high strength can be obtained.

Claims (7)

  1. 　ペロブスカイト構造化合物の単結晶粒子からなる単結晶粉末を用意する工程と、
    　分散相として、前記単結晶粉末を含む、セラミックスラリーを作製する工程と、
    　前記セラミックスラリーを磁場中で成形することによって、セラミック成形体を得る工程と、
    　前記セラミック成形体を焼結させる工程と
    を備える、ペロブスカイト構造化合物の焼結体の製造方法。     Preparing a single crystal powder comprising single crystal particles of a perovskite structure compound;
    Producing a ceramic slurry containing the single crystal powder as a dispersed phase;
    Forming a ceramic molded body by molding the ceramic slurry in a magnetic field;
    A method for producing a sintered body of a perovskite structure compound, comprising the step of sintering the ceramic molded body.
  2. 　前記単結晶粉末を構成するペロブスカイト構造化合物と同じペロブスカイト構造化合物の多結晶粒子からなる多結晶粉末を用意する工程をさらに備え、前記セラミックスラリーは、前記分散相として、前記単結晶粉末と前記多結晶粉末との双方を含む、請求項１に記載のペロブスカイト構造化合物の焼結体の製造方法。 A step of preparing a polycrystalline powder composed of polycrystalline particles of the same perovskite structure compound as the perovskite structure compound constituting the single crystal powder, and the ceramic slurry includes the single crystal powder and the polycrystalline as the dispersed phase. The manufacturing method of the sintered compact of the perovskite structure compound of Claim 1 containing both powder.
  3. 　前記セラミックスラリーにおいて、前記単結晶粉末は、前記分散相の５モル％以上を占める、請求項２に記載のペロブスカイト構造化合物の焼結体の製造方法。 The method for producing a sintered body of a perovskite structure compound according to claim 2, wherein the single crystal powder occupies 5 mol% or more of the dispersed phase in the ceramic slurry.
  4. 　前記セラミックスラリーにおいて、前記単結晶粉末は、前記分散相の９０モル％以下を占める、請求項２または３に記載のペロブスカイト構造化合物の焼結体の製造方法。 The method for producing a sintered body of a perovskite structure compound according to claim 2 or 3, wherein in the ceramic slurry, the single crystal powder occupies 90 mol% or less of the dispersed phase.
  5. 　前記単結晶粉末を用意する工程は、ペロブスカイト構造化合物の仮焼粉末をフラックス中で熱処理することによって、ペロブスカイト構造化合物の粒子を結晶成長させる工程を備える、請求項１ないし４のいずれかに記載のペロブスカイト構造化合物の焼結体の製造方法。 The step of preparing the single crystal powder includes a step of crystal-growing the particles of the perovskite structure compound by heat-treating the calcined powder of the perovskite structure compound in a flux. A method for producing a sintered body of a perovskite structure compound.
  6. 　前記フラックスとして、ＫＣｌおよびＮａＣｌの少なくとも一方が用いられる、請求項５に記載のペロブスカイト構造化合物の焼結体の製造方法。 The method for producing a sintered body of a perovskite structure compound according to claim 5, wherein at least one of KCl and NaCl is used as the flux.
  7. 　前記ペロブスカイト構造化合物は、ＰｂＴｉＯ３を主成分とするものである、請求項１ないし６のいずれかに記載のペロブスカイト構造化合物の焼結体の製造方法。 The perovskite structure compound, as a main component PbTiO 3, method for manufacturing a sintered body of a perovskite structure compound according to any one of claims 1 to 6.
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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012062210A (en) * 2010-09-15 2012-03-29 National Institute For Materials Science High hardness b4c oriented by ferromagnetic field technique and method for manufacturing the same
WO2013088926A1 (en) * 2011-12-12 2013-06-20 株式会社村田製作所 Piezoelectric oriented ceramic and production method therefor
US10655038B2 (en) 2016-10-25 2020-05-19 3M Innovative Properties Company Method of making magnetizable abrasive particles
US10774251B2 (en) 2016-10-25 2020-09-15 3M Innovative Properties Company Functional abrasive particles, abrasive articles, and methods of making the same
US10947432B2 (en) 2016-10-25 2021-03-16 3M Innovative Properties Company Magnetizable abrasive particle and method of making the same
US11072732B2 (en) 2016-10-25 2021-07-27 3M Innovative Properties Company Magnetizable abrasive particles and abrasive articles including them
US11253972B2 (en) 2016-10-25 2022-02-22 3M Innovative Properties Company Structured abrasive articles and methods of making the same
US11484990B2 (en) 2016-10-25 2022-11-01 3M Innovative Properties Company Bonded abrasive wheel and method of making the same
US11597860B2 (en) 2016-10-25 2023-03-07 3M Innovative Properties Company Magnetizable abrasive particle and method of making the same

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5676910B2 (en) * 2010-04-27 2015-02-25 キヤノン株式会社 Method for manufacturing ceramics and piezoelectric material
JP5799336B2 (en) * 2011-12-12 2015-10-21 株式会社村田製作所 Piezoelectrically oriented ceramics and manufacturing method thereof
JP2014012620A (en) 2012-07-05 2014-01-23 Murata Mfg Co Ltd Production method of orientation ceramic, orientation ceramic, and ceramic electronic component
JP6075702B2 (en) * 2013-05-10 2017-02-08 株式会社村田製作所 Piezoelectric ceramic electronic components

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005113205A (en) * 2003-10-08 2005-04-28 Japan Science & Technology Agency Method for manufacturing molding with crystal orientation
JP2008037064A (en) * 2006-08-10 2008-02-21 Murata Mfg Co Ltd Method for producing orientable ceramics

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005113205A (en) * 2003-10-08 2005-04-28 Japan Science & Technology Agency Method for manufacturing molding with crystal orientation
JP2008037064A (en) * 2006-08-10 2008-02-21 Murata Mfg Co Ltd Method for producing orientable ceramics

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
DENG, YU ET AL.: "Synthesis and characterization of single-crystal PbTi03 nonorods", MATERIALS LETTERS, vol. 59, 2005, pages 3272 - 3275 *
HIROSHI MASUMOTO ET AL.: "Kyo Yudentai no Haikosei ni Oyobosu Jiba no Eikyo", HIGH FIELD LABORATORY FOR SUPERCONDUCTING MATERIALS NENJI HOKOKU 2002 NENDO, 2003, pages 210 - 211 *

Cited By (10)

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Publication number Priority date Publication date Assignee Title
JP2012062210A (en) * 2010-09-15 2012-03-29 National Institute For Materials Science High hardness b4c oriented by ferromagnetic field technique and method for manufacturing the same
WO2013088926A1 (en) * 2011-12-12 2013-06-20 株式会社村田製作所 Piezoelectric oriented ceramic and production method therefor
JPWO2013088926A1 (en) * 2011-12-12 2015-04-27 株式会社村田製作所 Piezoelectrically oriented ceramics and manufacturing method thereof
US10655038B2 (en) 2016-10-25 2020-05-19 3M Innovative Properties Company Method of making magnetizable abrasive particles
US10774251B2 (en) 2016-10-25 2020-09-15 3M Innovative Properties Company Functional abrasive particles, abrasive articles, and methods of making the same
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US11597860B2 (en) 2016-10-25 2023-03-07 3M Innovative Properties Company Magnetizable abrasive particle and method of making the same

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