JP2008036816A - Method for producing non-ferromagnetic substance molding and non-ferromagnetic substance molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To orient not only a crystal axis having the greatest magnetic susceptibility but also other crystal axes. <P>SOLUTION: In a slurry production process 1, slurry containing a non-ferromagnetic material having anisotropic magnetic susceptibility such as a bismuth layer compound as a main component is produced. In the first orientation process 2, a magnetic field is applied in the first direction to the slurry in a slip-casting apparatus, and an axis (a) or an axis (b) having the substantially greatest magnetic susceptibility is oriented. In the second orientation process 3, while the magnetic susceptibility of the axis (a) or the axis (b) is maintained, the slip-casting apparatus is rotated by 90° in the horizontal direction, a magnetic field is applied in the second direction perpendicular to the first direction, and an axis (c), which is a crystal axis not oriented in the first orientation process 2, is oriented. In an orientation fixing process 4, the orientation of each crystal axis oriented in the first or second orientation processes 2 or 3 is fixed, and a molding is obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a non-ferromagnetic material molded body, and more particularly, a method for producing a non-ferromagnetic material molded body having anisotropy in magnetic susceptibility with controlled orientation of crystal axis orientation, and non-ferromagnetic material It relates to a molded body.

  Ceramic materials that are widely used as materials for electronic components are known to have crystal axis orientation orientation that contributes to improving the properties of electronic components. In recent years, research and development on crystal axis orientation control Has been actively conducted. In particular, in the field of piezoelectric components, lead-based piezoelectric ceramic materials such as lead zirconate titanate (PZT) have been used in the past, but development of lead-free piezoelectric ceramic materials that do not contain lead for environmental considerations Therefore, if piezoelectric characteristics such as electromechanical coupling coefficient can be improved by controlling the orientation of crystal axes, it is promising as a substitute for lead-based piezoelectric ceramic materials.

  Conventionally, a slurry is prepared by adding a solvent to a powder containing 90% by weight or more of a bismuth layered compound as a ceramic raw material powder, and a magnetic field of 1 T (Tesla) or more is applied to the slurry in one direction to apply the bismuth. There has already been proposed a method for producing a bismuth layered compound sintered body in which the slurry is solidified while the layered compound powder is oriented in a crystal plane perpendicular to the c-plane (Patent Document 1).

  Patent Document 1 focuses on the fact that a bismuth layered compound is a non-ferromagnetic material having anisotropy in magnetic susceptibility, and a crystal axis having a high magnetic susceptibility is obtained by applying a molding process to a slurry while applying a magnetic field in one direction. Thus, it becomes possible to easily obtain a molded body without requiring a complicated manufacturing process.

  The manufacturing method of Patent Document 1 has a greater degree of freedom in the thickness of the molded body than the conventional so-called sheet method, and can be crystal-oriented if it is a non-ferromagnetic material having anisotropy in magnetic susceptibility. It can be applied to many substances.

  As another conventional technique, a ceramic slurry containing nonmagnetic ceramic particles is coated on a base film to produce an unoriented sheet of a predetermined thickness, and the unoriented sheet is supported on the base film. As it is sent to the magnetic field application device, a magnetic field in a predetermined direction is applied, and the nonmagnetic ceramic particles in the unoriented sheet are oriented in the direction of the magnetic field to produce an oriented sheet. There has been proposed a method for manufacturing a piezoelectric ceramic component in which an orientation fixing sheet is obtained by fixing the orientation of magnetic ceramic particles (Patent Document 2).

  In this Patent Document 2, as shown in FIG. 7, an unoriented ceramic green sheet 101 is intermittently run in the direction of arrow a while being supported by a base film 102, and the ceramic green sheet 101 is moved in a first magnetic field application region 103. A magnetic field in a predetermined direction is applied to the sheet 101, and ultraviolet rays are irradiated from above through a mask 104 in which a translucent portion 104a is provided in the vicinity of the terminal end of the first magnetic field application region 103. After forming one orientation fixing portion 105, a magnetic field is applied in a direction different from the application direction of the first magnetic field application region 103 in the second magnetic field application region 106, and the end of the second magnetic field application region 106 is further applied. A method is disclosed in which the second alignment fixing portion 108 is obtained by irradiating ultraviolet rays from above in the vicinity 107 to fix the alignment of portions other than the alignment fixing portion 105.

JP 2002-121069 A JP 2004-6704 A

  However, in Patent Document 1, although the crystal axis orientation with the highest magnetic susceptibility can be oriented, other crystal axis orientations cannot be oriented. For example, the a-axis and b-axis can be different from each other like a bismuth layered compound. When the magnetic susceptibility is approximately the same and the magnetic susceptibility of the c-axis is lower than the magnetic susceptibility of the a-axis and the b-axis, the c-axis cannot be oriented. I couldn't.

  That is, in Patent Document 1, orientation can be imparted to the a-axis or b-axis, but the c-axis cannot be aligned in a certain direction toward an arbitrary direction. Thus, it could not be used for applications requiring c-axis orientation.

  In Patent Document 2, as described above, the magnetic field is applied twice to the ceramic green sheet 101 from different directions in the first and second magnetic field application regions 103 and 106. In this method, the magnetic susceptibility is applied. With respect to a large crystal axis (a-axis and b-axis in the case of a bismuth layered compound), the first orientation fixing portion 105 is oriented in the vertical direction, for example, and the second orientation fixing portion 108 is oriented in the horizontal direction, for example. The c-axis, which has a lower magnetic susceptibility than the a-axis and b-axis, is not oriented in the magnetic field direction, and it is not intended to orient the c-axis in a certain direction.

  The present invention has been made in view of such circumstances, and is a non-ferromagnetic material capable of imparting orientation not only to the crystal axis having a substantially maximum magnetic susceptibility but also to other crystal axes. It aims at providing the manufacturing method of a molded object, and a nonferromagnetic substance molded object.

  The inventors of the present invention have made extensive studies to achieve the above object, and applied a magnetic field from a predetermined direction to the ceramic slurry to impart orientation to the crystal axis with the maximum magnetic susceptibility and maintain the orientation. In other words, by applying a magnetic field again from a direction substantially perpendicular to the predetermined direction, it has been found that the orientation can be imparted to crystal axes other than the crystal axis having the maximum magnetic susceptibility to the magnetic field. It was.

  The present invention has been made based on such knowledge, and the method for producing a non-ferromagnetic material molded body according to the present invention applies a magnetic field to a slurry containing a non-ferromagnetic material having anisotropy in magnetic susceptibility. A method for producing a non-ferromagnetic substance molded body that forms a molded body by performing a molding process while producing a slurry containing the non-ferromagnetic material as a main component; Applying a magnetic field in the direction of, and imparting orientation to the first crystal axis in which the magnetic susceptibility of the crystal axis with respect to the magnetic field is substantially maximum, and orientation of the first crystal axis A second orientation imparting step in which a magnetic field is applied in a second direction substantially perpendicular to the first direction while maintaining the orientation, and orientation is imparted to crystal axes other than the first crystal axis; The alignment of each crystal axis given in the first and second orientation imparting steps It is characterized in that it comprises a orientation fixing step of fixing the sex.

  Note that “the crystal axis with the maximum magnetic susceptibility” means, for example, that the magnetic susceptibility is lower than the crystal axis with the maximum true susceptibility, and the magnetic susceptibility is not the maximum. In terms of the behavior, the crystal axis is such that the true magnetic susceptibility cannot be distinguished from the maximum crystal axis.

  In addition, when the present inventors conducted further earnest studies, when the first orientation imparting step and the second orientation imparting step described above were continuously performed without providing a time interval, It has been found that the orientation of crystal axes other than the first crystal axis can be improved as compared with the case where the time interval is set.

  That is, the method for producing a non-ferromagnetic material molded body of the present invention is characterized in that the first orientation imparting step and the second orientation imparting step are continuously performed.

  Furthermore, as a result of extensive research by the present inventors, by controlling the viscosity of the slurry to 30 to 200 mPa · s, the orientation of the crystal axes other than the crystal axes at which the magnetic susceptibility to the magnetic field is substantially maximized. It was found that can be improved effectively.

  Therefore, the method for producing a non-ferromagnetic material molded body of the present invention is characterized in that the viscosity of the slurry produced in the slurry production step is 30 to 200 mPa · s.

  In addition, the present invention can exhibit particularly remarkable effects in a bismuth layered compound having a large difference in magnetic susceptibility between the a-axis and b-axis of the crystal axis and the c-axis.

  Therefore, the method for producing a non-ferromagnetic material molded body of the present invention is characterized in that the non-ferromagnetic material is a ceramic material mainly composed of a bismuth layered compound.

  Moreover, the non-ferromagnetic substance molded body of the present invention can be obtained by using the method for producing a non-ferromagnetic substance molded body of the present invention. That is, the non-ferromagnetic material molded body of the present invention is a non-ferromagnetic material molded body obtained by subjecting a slurry containing a non-ferromagnetic material having anisotropy in magnetic susceptibility to a molding process while applying a magnetic field. Thus, an orientation is imparted to crystal axes other than the first crystal axis in which the magnetic susceptibility of the crystal axis with respect to the magnetic field is substantially maximum.

  In addition, the present invention can exhibit particularly remarkable effects in a bismuth layered compound having a large difference in magnetic susceptibility between the a-axis and b-axis of the crystal axis and the c-axis. Thus, the non-ferromagnetic material molded body of the present invention is characterized in that the non-ferromagnetic material is a ceramic material mainly composed of a bismuth layered compound, and the crystal axis other than the first crystal axis is the c-axis. .

  According to the method for producing a non-ferromagnetic material molded body of the present invention, a slurry production step of producing a slurry mainly composed of a non-ferromagnetic material having anisotropy in magnetic susceptibility, and a first direction with respect to the slurry Applying a magnetic field to the first crystal axis, wherein the first crystal axis has a substantially maximum magnetic susceptibility with respect to the magnetic field, and imparts orientation to the first crystal axis; A second orientation imparting step of applying a magnetic field in a second direction substantially perpendicular to the first direction in a maintained state to impart orientation to a crystal axis other than the first crystal axis; Orientation fixing step of fixing the orientation of each crystal axis given in the first and second orientation imparting steps, so that only the first crystal axis having a magnetic susceptibility to the magnetic field is substantially maximum. The other crystal axes can also be fixed in the orientation, and therefore in the first direction Further while maintaining the direction state becomes the orientation of the higher order is given, the electrical characteristics can be easily produced a thick block-like electronic component molded article having good thickness.

  In addition, since the first orientation imparting step and the second orientation imparting step are continuously performed, the orientation of crystal axes other than the first crystal axis can be further improved. .

  In addition, since the viscosity of the slurry prepared in the slurry preparation step is 30 to 200 mPa · s, not only the crystal axis with which the magnetic susceptibility to the magnetic field is substantially maximized but also the orientation of other crystal axes. Can also be good.

  In the manufacturing method of the present invention, since the non-ferromagnetic material is a ceramic material containing a bismuth layered compound as a main component, not only the a-axis and b-axis having substantially the same susceptibility but also the c-axis having the smallest crystal axis. Orientation can be imparted to the crystal axis, and various piezoelectric parts having excellent piezoelectric characteristics can be realized even if the piezoelectric ceramic material does not contain lead.

  The non-ferromagnetic material molded body of the present invention is a non-ferromagnetic material molded body obtained by subjecting a slurry containing a non-ferromagnetic material having anisotropy in magnetic susceptibility to a molding process while applying a magnetic field. However, not only is the orientation given to the first crystal axis where the magnetic susceptibility of the crystal axis with respect to the magnetic field is substantially maximum, but the orientation is also given to crystal axes other than the first crystal axis. Therefore, it can be usefully used in applications that require orientation in a crystal axis other than the first crystal axis.

  In the non-ferromagnetic material molded body of the present invention, the non-ferromagnetic material is a ceramic material whose main component is a bismuth layered compound, and the magnetic susceptibility is not limited to the substantially equivalent a-axis and b-axis. The orientation is given to the c-axis with the smallest. A non-ferromagnetic material molded body having a high orientation of the c-axis, which is the longest axis among the crystal axes of the bismuth layered compound, can be obtained, and various piezoelectric parts having excellent piezoelectric characteristics when an electric field is applied can be obtained.

  Next, an embodiment of the present invention will be described in detail.

  FIG. 1 is a manufacturing process diagram showing a method for manufacturing a non-ferromagnetic material according to the present invention.

  In the slurry preparation step 1, a slurry mainly containing a non-ferromagnetic material having anisotropy in magnetic susceptibility is prepared.

Specific examples of the “non-ferromagnetic material having anisotropy in magnetic susceptibility” include CaBi ₄ Ti ₄ O ₁₅ , BaBi ₄ Ti ₄ O ₁₅ , BaBi ₂ Ta ₂ O ₉ , BaBi ₂ Nb ₂ O _{9 and the} like. bismuth layer _{compound, Sr 1.9 Ca 0.1 NaNb 5 O} 15, SrNb 2 O 6, BaNb tungsten bronze type compound such as _{2 O 6, Ho 2 Ti 2} O 7, Dy pyrochlore compounds such as 2 _Ti 2 _{O 7,} ZnO, etc. This ceramic material is practical for use in electronic parts, and in particular, a bismuth layered compound having extremely large crystal anisotropy is preferably used, but intermetallic compounds and polymer materials can also be used.

  Next, a method for preparing a slurry of a non-ferromagnetic material will be specifically described.

First, raw materials such as CaCO ₃ , BaCO ₃ , Bi ₂ O ₃ , Nb ₂ O ₅ , Ta ₂ O ₅ , and TiO ₂ are prepared as starting materials.

  Next, a predetermined amount of these starting materials are weighed, and a desired additive is weighed as necessary. The weighed material is put into a ball mill containing a grinding medium such as partially stabilized zirconia (PSZ). The mixture is sufficiently mixed and pulverized in a wet state, and then subjected to a drying treatment, followed by a calcining treatment for a predetermined time, and the obtained calcined material is crushed to produce a calcined powder.

  Next, this calcined powder is again put into a ball mill and sufficiently wet pulverized to produce a raw material powder mainly composed of a non-ferromagnetic substance. An appropriate amount of a dispersant, water, and an organic binder are mixed with the raw material powder to prepare a slurry.

  Here, the viscosity of the slurry is controlled to 30 to 200 mPa · s by adjusting the blending ratio of the raw material powder and water.

  That is, when the viscosity of the slurry is less than 30 mPa · s, the fluidity of the slurry increases, and it becomes difficult to maintain the orientation imparted in the first orientation imparting step, which will be described later. There is a risk of inviting. On the other hand, when the viscosity of the slurry exceeds 200 mPa · s, the viscosity of the slurry increases, so that it becomes difficult to orient the crystal axes regardless of the magnitude of the magnetic susceptibility. There is a fear.

  Therefore, in the present embodiment, the viscosity of the slurry is controlled to be 30 to 200 mPa · s, preferably 60 to 110 mPa · s.

  Next, in the first orientation imparting step 2, a first magnetic field is applied to the slurry accommodated in the slurry casting apparatus (molding apparatus) in the horizontal direction, and the magnetic susceptibility to the magnetic field is substantially maximized. The first crystal axis is oriented in the magnetic field application direction.

  That is, first, a superconducting magnet as shown in FIG. 2 is prepared.

  The superconducting magnet 5 is formed in a cylindrical shape having a hollow portion 6, and a coil 7 is embedded in a spiral shape. When a voltage is applied to the superconducting magnet 5 and energized, a magnetic field is generated in the arrow X direction (longitudinal direction). Although the superconducting magnet 5 is used in the present embodiment, a normal electromagnet can also be used.

  Next, a slurry casting apparatus is disposed in the cavity 6 and a molding process is performed in a magnetic field.

  FIG. 3 is a schematic view of a slurry casting apparatus, in which 8 is a mold and 9 is a porous absorbent plate.

  That is, a mud casting apparatus is arranged in the cavity 6 of the superconducting magnet 5, and the superconducting magnet 5 is energized to generate a magnetic field in the direction of the arrow X. The slurry 10 is poured from (shown), and the slurry 10 is absorbed by the porous absorbent plate 9 to perform a forming process.

  At this time, since the magnetic field is applied to the slurry 10 in the direction of the arrow X, the crystal grains of the slurry have the first crystal axis whose magnetic susceptibility is substantially maximum oriented in the direction in which the magnetic field is applied. Crystal axes are randomly oriented in any direction.

  For example, if the magnetic susceptibility of the crystal axis is a-axis> b-axis> c-axis, when a magnetic field is applied in the direction of the arrow X and the magnetic field is generated, the a-axis susceptibility is compared with the susceptibility of the b-axis or c-axis Since it is large, the a-axis becomes the first crystal axis and is oriented in the direction of arrow X, which is the direction of application of the magnetic field. At this time, the b-axis and the c-axis are randomly oriented in a plane perpendicular to the arrow X direction.

  Next, in the second orientation imparting step 3, first, the slurry casting apparatus is rotated 90 ° in the horizontal direction so as not to give vibration to the slurry 10. In this state, the superconducting magnet 5 is energized again and a second magnetic field application is performed to generate a magnetic field in the direction of the arrow X. As a result, the slurry 10 is applied in a direction perpendicular to the direction of application in the first orientation imparting step 2, and since the first orientation is maintained, the first magnetic susceptibility is maximum. Crystal axes other than the crystal axes are oriented.

  That is, in the previous example, the a-axis (first crystal axis) to which the orientation is imparted in the first orientation imparting step 2 is oriented in a direction perpendicular to the second magnetic field application direction. In this state, the orientation is maintained, and the b-axis has a higher magnetic susceptibility than the c-axis, so that the b-axis is oriented in the arrow X direction. As a result, the c-axis is oriented in a third direction perpendicular to the first and second application directions.

  Next, in the orientation fixing step 4, the slurry is dried for a predetermined time, whereby a non-ferromagnetic molded body is manufactured.

  The first crystal having the maximum magnetic susceptibility is generated by generating the magnetic field twice so that the application directions are perpendicular to each other, and performing the forming process in the magnetic field. Non-ferromagnetic material molding in which orientation can be imparted to crystal axes other than the axis, and thereby orientation is imparted to crystal axes other than the crystal axis that has a substantially maximum magnetic susceptibility to a magnetic field. The body can be manufactured.

  In the present embodiment, the second orientation imparting step 3 and the orientation fixing step 4 are performed separately. In the second orientation imparting step 3, while applying the second magnetic field, Drying may be started, and the second orientation imparting step 3 and the orientation fixing step 4 may be performed simultaneously.

In the present embodiment, the magnetic field is applied to the slurry 10 so as to be perpendicular to each other simply by rotating the slurry casting apparatus. Therefore, the single superconducting magnet 5 performs twice from different directions. Can be applied.

  Then, a piezoelectric molded part can be formed using a ceramic molded body in which the orientation of each crystal axis is controlled. Therefore, a thick block-shaped ceramic molded body can be easily manufactured without depending on the sheet method. Thus, it is possible to obtain a piezoelectric component having excellent piezoelectric characteristics even if it is a lead-free lead-free system.

  In addition, this invention is not limited to the said embodiment, In order to obtain favorable orientation, the magnitude | size of the applied magnetic field is preferable 1T or more.

  In the above embodiment, the case where the susceptibility of the crystal axis is a-axis> b-axis> c-axis has been described as an example. However, in the case of a bismuth layered compound or the like, the susceptibility is a-axis≈b-axis> c-axis. Such a relationship holds. In this case, in the first orientation imparting step 2, orientation is imparted to one of the crystal axes (a axis or b axis) out of the crystal axes excluding the crystal axis having the minimum magnetic susceptibility (c axis). Next, in the second orientation imparting step 3, the a-axis is aligned with respect to the one in which the a-axis is oriented in the first orientation imparting step 2, and the a-axis is relative to the one in which the b-axis is oriented. Oriented. That is, as a result of the a-axis or b-axis being oriented in any one of the magnetic field application directions in the first and second orientation imparting steps 2 and 3, the c-axis having the minimum magnetic susceptibility is necessarily oriented.

  Moreover, in the said embodiment, although the 1st orientation provision process 1 and the 2nd orientation provision process 2 are performed continuously without providing time intervals, the 2nd orientation provision process 2 You may make it provide a fixed time interval between. That is, when a time interval is provided between the first orientation imparting step 1 and the second orientation imparting step 2, the first orientation imparting step 1 and the second orientation imparting step 2 Although the orientation is slightly reduced as compared with the case where the steps are continuously performed, the orientation of each crystal axis can be ensured.

  However, if the orientation is fixed between the first orientation imparting step 2 and the second orientation imparting step 3, the orientation other than the crystal axis having a high magnetic susceptibility is also fixed at random, It is desirable not to do as much as possible that the orientation is fixed.

  In the above embodiment, the first and second magnetic fields are applied in directions perpendicular to each other on the XY plane, but may be applied in directions perpendicular to each other on the XZ plane. The magnetic field may be applied so that the magnetic field is generated in a substantially vertical direction even if it is not truly vertical.

  Further, the method for fixing the orientation of the crystal axis is not limited to the above-described drying treatment, and the orientation may be fixed by ultraviolet irradiation or the like.

  By using the method for producing a non-ferromagnetic material molded body as described above, a non-ferromagnetic material obtained by subjecting a slurry containing a non-ferromagnetic material having anisotropy in magnetic susceptibility to a molding process while applying a magnetic field. Even in the case of a material molded body, a non-ferromagnetic material molded body can be obtained in which orientation is imparted to crystal axes other than the first crystal axis in which the magnetic susceptibility of the crystal axis with respect to the magnetic field is substantially maximum. . In particular, when the non-ferromagnetic material is mainly composed of a bismuth layered compound, a non-ferromagnetic material molded body in which orientation is imparted to the c-axis having the smallest magnetic susceptibility can be obtained. In the bismuth layered compound, since the c-axis is the longest axis among the crystal axes, it is possible to provide a piezoelectric component having a large piezoelectric property and displacement when an electric field is applied depending on the application.

  In the above, when a ceramic material is used as the non-ferromagnetic substance material and the non-ferromagnetic substance molded body of the present invention is used for a component body such as a piezoelectric part, the ceramic molding solidified through the orientation fixing step. After the body is fired to obtain a ceramic sintered body, it is generally used as a piezoelectric component body. For example, when using a polymer material, it should be used as a non-ferromagnetic material molded body. Is also possible.

  When such a non-ferromagnetic material molded body is used as an electronic component, for example, it is useful to use it as a semiconductor protective film, a printed circuit board, an electromagnetic shielding material, or the like, but is not limited thereto.

  Next, examples of the present invention will be specifically described.

  As a non-ferromagnetic material having anisotropy in magnetic susceptibility, a bismuth layered compound having an a-axis and b-axis susceptibility that is equally high and a c-axis susceptibility lower than that of the a-axis and b-axis is used. The crystal orientation effect was confirmed.

That is, _{first, CaCO 3, Bi 2 O 3} , TiO 2, and prepared MnCO _3, bismuth layer represented by the composition formula CaBi ₄ Ti ₄ O ₁₅ containing a MnCO ₃ 0.5 wt% as the starting material The starting material was weighed to obtain the compound.

  Next, this weighed product is put into a ball mill containing PSZ and mixed wet for about 16 hours. The resulting mixture is dried, then calcined at 1200 ° C. for 2 hours, and further rotated. Using a pulverizer, the powder was crushed by a dry method for 1 minute to obtain a calcined powder.

  Next, the calcined powder is again put into the ball mill and subjected to wet pulverization for about 100 hours to obtain a raw material powder. Further, water and an organic binder ( Vinyl acetate resin) was mixed to prepare six types of ceramic slurries (slurries A to F).

  Next, the viscosity of each of the slurries A to F was measured with a vibratory viscometer.

この表１に示すように、本実施例では原料粉末と水との配合比率を異ならせることにより、粘性率が１５〜２４０ｍＰａ・ｓの範囲に調製された６種類のスラリーＡ〜Ｆを得た。 Table 1 shows the contents and viscosity in each slurry of raw material powder, water, and organic binder.

As shown in Table 1, in this example, six types of slurries A to F having a viscosity of 15 to 240 mPa · s were obtained by varying the mixing ratio of the raw material powder and water. .

  Next, an acrylic acid salt as a dispersant of 0.5% by weight is added to these slurries A to F, and ultrasonic vibration is applied for 5 minutes while dispersing with a stir bar to sufficiently disperse the raw material powder. Stir.

  Then, the slurry A to F thus obtained is poured into the mold of the slurry casting apparatus shown in FIG. 3, and the slurry casting apparatus is arranged in the cavity 6 of the superconducting magnet 5 shown in FIG. The molding process was performed while applying a magnetic field by the magnetic field application method shown in (1) to (5).

[Magnetic field application method]
(1) As a first magnetic field application, a 12T magnetic field is applied for 15 minutes in the horizontal direction, and then the mud casting apparatus is rotated 90 ° in the horizontal direction so as not to vibrate the sample (slurry). As a magnetic field application, a 12T magnetic field was applied in the horizontal direction for 4 hours. Note that the second magnetic field is applied in a direction perpendicular to the first magnetic field application direction.

(2) After applying a 12T magnetic field in the horizontal direction for 15 minutes as the first magnetic field application, the mud casting apparatus is taken out of the superconducting magnet 5 and left for 1 minute. A mud casting apparatus was arranged in the cavity 6 of the superconducting magnet 5 so as to be rotated 90 ° in the direction, and a 12 T magnetic field was applied in the horizontal direction for 4 hours as the second magnetic field application. In this case as well, as in (1) above, the second magnetic field is applied in a direction perpendicular to the first magnetic field application direction.

(3) As a first magnetic field application, a 12T magnetic field is applied in the horizontal direction for 4 hours, and then the mud casting apparatus is removed from the superconducting magnet 5 and subjected to ultrasonic vibration for 5 minutes, and then the sample is stirred. A mud casting device is arranged in the cavity 6 of the superconducting magnet 5 so that it is rotated by 90 ° in the horizontal direction when the first magnetic field is applied, and a 12 T magnetic field is applied in the horizontal direction as the second magnetic field application. For 4 hours. In this case as well, as in (1) above, the second magnetic field is applied in a direction perpendicular to the first magnetic field application direction.

(4) Only a 12T magnetic field was applied in the horizontal direction for 4 hours, and the second magnetic field application was not performed.

(5) Mud casting was performed without applying a magnetic field.

  Next, the slurry subjected to the molding treatments (1) to (5) above is dried at 150 ° C. for 12 hours and die-molded, and has outer dimensions of a width W of 40 mm, a length H of 35 mm, and a thickness T of 5 mm. Ceramic molded bodies having sample numbers 1 to 18 were prepared.

  Next, the ceramic molded body thus obtained is heat-treated at a temperature of 500 ° C. for 2 hours to remove the organic binder, and then subjected to a firing treatment in the atmosphere at a temperature of 1200 ° C. for 2 hours. Were obtained. Ceramic sintered bodies of sample numbers 1 to 18 having outer dimensions of 34 mm, length H of 29 mm, and thickness T of 4.2 mm were obtained.

  FIG. 4 shows the appearance of the ceramic sintered body, where P indicates the first magnetic field application direction and Q indicates the second magnetic field application direction.

  Next, for surface A (W × H surface), surface B (W × T surface), and surface C (H × T surface), an X-ray diffraction method (source CuKα, 40 kV, 200 mA) is used. The X-ray peak intensity at a diffraction angle of 20 ° to 80 ° was measured. For comparison, the X-ray peak intensity of each crystal plane of a comparative powder sample obtained by pulverizing a ceramic molded body was also measured.

ここで、ΣＩ（ＨＫＬ）は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。また、ΣＩｏ（ＨＫＬ）は上記比較用粉末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）は上記比較用粉末試料の全結晶面（ｈｋｌ）のＸ線ピーク強度の総和である。 Next, the orientation degree F1 of the (l00) plane and the (0l0) plane indicating the orientation of the a-axis and the b-axis and the orientation degree F2 of the (00l) plane indicating the orientation of the c-axis based on the formula (1) by the Lotgering method. Was calculated for each of the surfaces A to C.

Here, ΣI (HKL) is the sum of X-ray peak intensities of specific crystal planes (HKL) in the ceramic sintered body, and ΣI (hkl) is the X-ray peak of all crystal planes (hkl) of the ceramic sintered body. The sum of strength. ΣIo (HKL) is the sum of X-ray peak intensities of specific crystal planes (HKL) of the comparative powder sample, and ΣIo (hkl) is X-rays of all crystal planes (hkl) of the comparative powder sample. The sum of peak intensities.

  Next, for each of the samples Nos. 1 to 18, as shown in FIG. 5, the width T ′ in which both main surfaces are parallel to the surface B and the length direction is orthogonal to the surface C is 1 mm, and the length W ′. A rectangular plate-shaped piezoelectric ceramic body 20 having a thickness of 5 mm and a thickness H ′ of 0.25 mm was cut out.

  Next, silver paste is applied to both end faces (H ′ × T ′) of the piezoelectric ceramic body 20 and baked to form a conductive portion, and a DC voltage of 5 kV / mm is applied for 10 minutes in an insulating oil at 150 ° C. Then, the polarization treatment was performed. Next, a predetermined region of the conductive portion was removed, and electrodes 21a and 21b were formed so that the distance L from one end in the width direction (T ′) of the piezoelectric ceramic body 20 was 4 mm as shown in FIG. The electrodes 21a and 21b are opposed to each other within a range of 3 mm at the center in the length direction.

Then, using an impedance analyzer (Hewlett-Packard HP4194A), based on the ANSI / IEEE Standard was measured electromechanical coupling factor _{k 15} in the thickness shear vibration.

Table 2 shows slurry Nos. 1 to 18 of sample numbers 1-18. , Magnetic field application method, the crystal surface of the surface A~ plane C (L00) and (0l0), shows the respective orientation F1, F2 and the electromechanical coupling coefficient _{k 15} in the (00l).

表２に示すように試料番号１、２は、磁場を印加していないため、結晶粒子はランダムに配向しており、面Ａ〜面Ｃの、（ｌ００）面及び（０ｌ０）面、（００ｌ）面における各配向度Ｆ１、Ｆ２は６〜１２％と低く、電気機械結合係数ｋ₁₅も１３．４〜１３．５％と低かった。 The degree of orientation indicates a value normalized by 0% when non-oriented and 100% when all crystal grains are oriented.

As shown in Table 2, in Sample Nos. 1 and 2, since no magnetic field was applied, the crystal grains were randomly oriented, and the (l00) plane and (0l0) plane of planes A to C, (00l ) each orientation F1, F2 is as low as 6-12% in surface, electromechanical coupling factor k ₁₅ was low and 13.4 to 13.5%.

In Sample Nos. 3 and 4, since the magnetic field is applied from the horizontal direction (arrow P direction) with respect to the surface B, the a-axis and b-axis orientation degrees having a large magnetic susceptibility are obtained on the surface B, that is, the (100) surface. The orientation degree F1 of the (010) plane is as high as 71 to 78%, and the orientation is imparted. However, in the plane A and the plane C, the degree of orientation of each crystal axis is as low as 6 to 16%, and the crystal axes are randomly It was in an arbitrary direction, and the electromechanical coupling coefficient k ₁₅ was also as low as 12.1 to 12.4%.

In Sample Nos. 17 and 18, only the orientation degree F1 on the (100) plane and the (010) plane of the plane C is as high as 67 to 76%, and the a-axis orientation on the plane C is recognized, but the plane A In plane B, the crystal axes are randomly oriented in an arbitrary direction. Therefore, the degree of orientation in plane A and plane B is as low as 7 to 14%. Therefore, the electromechanical coupling coefficient k ₁₅ is also 14.9 to It was as low as 15.3%. In Sample Nos. 17 and 18, the magnetic field was applied twice, but after applying the first magnetic field, the ultrasonic vibration was applied to stir the slurry. Since the orientation effect is removed and the second magnetic field application is performed in the horizontal direction (arrow Q direction) with respect to the surface C, the a-axis and b-axis having high magnetic susceptibility with respect to the surface C, that is, ( This is probably because only the (100) plane and the (010) plane were oriented.

In contrast, Sample Nos. 5 to 16 applied a magnetic field in the direction of the arrow Q perpendicular to the direction of the arrow P after applying the magnetic field in the direction of the arrow P. The orientation degree F1 of the (0l0) plane is as high as 35 to 71%, and orientation is imparted to the a-axis, and in the plane A, the orientation degree F2 of the (00l) plane is 50 to 67% and orientation is imparted to the c-axis. is, thus also imparted orientation to any of the crystal axis, it was found that the electromechanical coupling coefficient k ₁₅ is also improved with 20.0 to 23.0%.

When a time interval of 1 minute is provided between the first magnetic field application and the second magnetic field application as in sample numbers 11 to 15, the degree of orientation of the c-axis on the surface A is 50 to 55. However, when the first magnetic field application and the second magnetic field application were continuously performed without providing a time interval as in sample numbers 5 to 10, the c-axis in the plane A The degree of orientation is as high as 57 to 63%. From these results, the first magnetic field application and the second magnetic field application were performed continuously without providing a time interval. It was found that the orientation degree F2 of the (00l) plane in A can be increased, and a better electromechanical coupling coefficient k ₁₅ can be obtained.

  Further, as can be seen from the comparison with sample numbers 5 to 10 and sample numbers 11 to 16, when the magnetic field application method is the same, the viscosity of the ceramic slurry is 30 to 200 mPa · s and the degree of orientation of the c-axis of the surface A In particular, it was confirmed that the degree of orientation of the c-axis was higher at 60 to 110 mPa · s.

It is a manufacturing-process figure which shows one Embodiment of the manufacturing method of the nonferromagnetic substance molded object which concerns on this invention. It is a perspective view which shows the outline of the superconducting magnet used by the said embodiment. It is a figure which shows the outline of the mud casting apparatus used in the said embodiment. It is a perspective view of the ceramic sintered compact manufactured by the present Example. FIG. 5 is a perspective view of a piezoelectric ceramic body obtained by cutting out the ceramic sintered body of FIG. 4. It is a perspective view which shows the external appearance of the piezoelectric component obtained in the Example. It is a top view of the ceramic green sheet for demonstrating the manufacturing method of the piezoelectric ceramic component disclosed by patent document 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Slurry preparation process 2 1st orientation provision process 3 2nd orientation provision process 4 Orientation fixing process 10 Slurry

Claims (6)

A method for producing a non-ferromagnetic material molded body that forms a molded body by applying a molding process while applying a magnetic field to a slurry containing a non-ferromagnetic material having anisotropy in magnetic susceptibility,
A slurry preparing step for preparing a slurry containing the non-ferromagnetic material as a main component, and a magnetic field is applied to the slurry in a first direction so that a susceptibility of a crystal axis with respect to the magnetic field is substantially maximum. A first orientation imparting step for imparting orientation to the crystal axis, and a magnetic field is applied in a second direction substantially perpendicular to the first direction while maintaining the orientation of the first crystal axis. Fixing the orientation of each crystal axis given in the second orientation imparting step for imparting orientation to crystal axes other than the first crystal axis and the first and second orientation imparting steps A method for producing a non-ferromagnetic material molded body comprising an orientation fixing step.   The method for producing a non-ferromagnetic substance molded body according to claim 1, wherein the first orientation imparting step and the second orientation imparting step are continuously performed.   The method for producing a non-ferromagnetic substance molded body according to claim 1 or 2, wherein a viscosity of the slurry produced in the slurry production step is 30 to 200 mPa · s.   4. The method for producing a non-ferromagnetic material molded body according to claim 1, wherein the non-ferromagnetic material is a ceramic material mainly composed of a bismuth layered compound.   A non-ferromagnetic material molded body obtained by subjecting a slurry containing a non-ferromagnetic material having anisotropy in magnetic susceptibility to a molding process while applying a magnetic field, wherein the magnetic axis has a magnetic susceptibility substantially equal to the magnetic field. A non-ferromagnetic material molded body, wherein orientation is imparted to crystal axes other than the maximum first crystal axis.   6. The non-ferromagnetic material molding according to claim 5, wherein the non-ferromagnetic material is a ceramic material mainly composed of a bismuth layered compound, and a crystal axis other than the first crystal axis is a c-axis. body.

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