Bismuth ferrite-barium titanate textured piezoelectric ceramic material with low sintering temperature and high piezoelectric property and preparation method of bismuth ferrite-barium titanate textured piezoelectric ceramic material

Abstract

The invention relates to the technical field of piezoelectric ceramic material preparation, and discloses a bismuth ferrite-barium titanate textured piezoelectric ceramic material with low sintering temperature and high piezoelectric property and a preparation method thereof, and the preparation method comprises the following steps: preparing a bismuth ferrite precursor template with copper oxide loaded on the surface; dispersing the template, barium titanate, bismuth oxide powder and a hyperbranched polyesteramide dispersing agent into photosensitive resin to prepare slurry; performing slip casting and in-situ photocuring under a static strong magnetic field; and carrying out glue discharging and reactive sintering to obtain a target product. An interface liquid phase is formed at the initial stage of sintering by using copper oxide on the surface of the template, and template particles are anchored through capillary force, so that template deflection in the densification process is inhibited, and the ceramic texture degree is improved; meanwhile, bismuth volatilization is inhibited through liquid-phase-assisted low-temperature sintering, the leakage current of the material is reduced, and the prepared ceramic has a high piezoelectric constant, a high Curie temperature and good insulativity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of piezoelectric ceramic material preparation, in particular to a bismuth ferrite-barium titanate textured piezoelectric ceramic material with low sintering temperature and high piezoelectric performance and a preparation method thereof. BACKGROUND

[0002] The bismuth ferrite-barium titanate solid solution ceramic has a high Curie temperature and is an important high-temperature lead-free piezoelectric material. However, bismuth is extremely volatile at high temperatures, and when prepared by a traditional high-temperature solid-phase sintering process, oxygen vacancies and bismuth vacancy defects are easily generated in the crystal lattice. These defects can significantly increase the leakage current density of the material, making it difficult to withstand the high applied electric field required for polarization and limiting the improvement of piezoelectric performance.

[0003] Although the grain texturing technology can improve the piezoelectric activity of the material, a liquid-phase aid is often introduced in the preparation process to reduce the sintering temperature. In practical applications, there is a contradiction between the introduction of the liquid-phase aid and the maintenance of a high texturing degree. When the aid is randomly distributed in the matrix, the liquid phase formed in the early stage of sintering will have a lubricating effect, causing the template particles that have been aligned by the magnetic field or tape casting process to be rearranged and deflected. This disordered particle movement destroys the preset orientation structure, resulting in a decrease in the texturing degree of the sintered ceramic and making it difficult to achieve the expected performance enhancement effect.

[0004] In addition, in the magnetic field assisted forming process, the rheological properties of the ceramic slurry have a great influence on the orientation efficiency. The slurry needs to meet the requirements of high solid content to ensure the density of the green body and low viscosity to reduce the rotational resistance of the template particles. Since bismuth-based and barium-based oxide powders have a high density, they are prone to sedimentation and agglomeration in the organic resin system. Conventional dispersants are difficult to maintain the dispersion stability of such high-density multi-phase mixed powders, which can easily cause deterioration of the rheological properties of the slurry and uneven distribution of components, and further cause structural defects such as micro-pores in the ceramic, affecting the density and insulation performance of the material. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a bismuth ferrite-barium titanate textured piezoelectric ceramic material with low sintering temperature and high piezoelectric performance and a preparation method thereof, which solves the technical problems of a decrease in the texturing degree caused by the random distribution of the liquid-phase aid and the inability to effectively polarize due to excessive leakage current caused by high-temperature sintering during the preparation process of the bismuth ferrite-barium titanate textured ceramic.

[0006] To achieve the above object, the present application is implemented by the following technical solutions: The first aspect of the present application provides a BiFeO3-BaTiO3 textured piezoelectric ceramic material with low sintering temperature and high piezoelectric performance. The material is prepared by a slurry system containing inorganic solid powder and organic carrier through magnetic field orientation, solidification and sintering. The raw material components of the slurry system include, by weight fraction, 20-25 parts of pre-synthesized BaTiO3 powder, 25-30 parts of Bi2O3 powder, 45-50 parts of BiFeO3 precursor template loaded with CuO on the surface, 0.5-1.5 parts of hyperbranched polyester amide dispersant, and 15-25 parts of photosensitive resin premix.

[0007] In the BiFeO3-BaTiO3 textured piezoelectric ceramic material with low sintering temperature and high piezoelectric performance, the BiFeO3 precursor template loaded with CuO on the surface is a core-shell composite powder, the core of which is a Bi2Fe2O9 particle with a rod structure, and the shell is CuO nanoparticles adsorbed on the surface of the core. The loading amount of CuO is 0.5-3.0% of the total molar amount of the BiFeO3-BaTiO3 textured piezoelectric ceramic material.

[0008] In the BiFeO3-BaTiO3 textured piezoelectric ceramic material with low sintering temperature and high piezoelectric performance, the photosensitive resin premix is a mixture of 1,6-hexanediol diacrylate, trimethylolpropane triacrylate and 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide.

[0009] In the BiFeO3-BaTiO3 textured piezoelectric ceramic material with low sintering temperature and high piezoelectric performance, the photosensitive resin premix is a mixture of 1,6-hexanediol diacrylate, trimethylolpropane triacrylate and 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide.

[0010] In the BiFeO3-BaTiO3 textured piezoelectric ceramic material with low sintering temperature and high piezoelectric performance, the hyperbranched polyester amide dispersant is prepared by ring-opening reaction and melt polycondensation reaction of diethanolamine and succinic anhydride at a molar ratio of 1.0:1.0 to 1.2:1.0.

[0011] The second aspect of the present application provides a preparation method of the BiFeO3-BaTiO3 textured piezoelectric ceramic material with low sintering temperature and high piezoelectric performance, which comprises the following steps: S1, synthesizing rod-shaped Bi2Fe2O9 powder by molten salt method. The specific process is: according to the molar ratio of Bi2O3 to Fe2O3 of 1:2, adding mixed molten salt of NaCl and KCl with a mass ratio of 1:1, and keeping at 800-900℃ for 4-8 hours, then washing and drying to obtain the rod-shaped Bi2Fe2O9 powder; S2, preparing the surface-loaded copper oxide bismuth ferrite precursor template. The specific process is: dispersing the rod-shaped ferriferrous bismuth oxide powder in a copper nitrate solution with a concentration of 0.05 mol / L to 0.2 mol / L, adding urea as a precipitating agent, and reacting at a constant temperature of 90 DEG C to 95 DEG C for 2 to 4 hours, then separating and drying, and calcining at 450 DEG C to 500 DEG C for 2 hours to obtain the surface-loaded copper oxide bismuth ferrite precursor template; S3, preparing the ceramic slurry. The specific process is: first, preparing a hyperbranched polyester amide dispersant by mixing diethanolamine with succinic anhydride, reacting at 140 DEG C to 150 DEG C for 2 to 3 hours, then increasing the temperature to 160 DEG C to 170 DEG C, and polycondensing under a vacuum degree of -0.08 MPa to -0.09 MPa for 4 to 6 hours; then dispersing the pre-synthesized barium titanate powder and the bismuth oxide powder in the photosensitive resin premix liquid containing the hyperbranched polyester amide dispersant, and adding the surface-loaded copper oxide bismuth ferrite precursor template and mixing uniformly; S4, magnetic field assisted orientation and solidification. The specific process is: injecting the ceramic slurry into a mold, and performing orientation treatment under a static magnetic field with a magnetic induction intensity of 6 to 10 tesla for 5 to 10 minutes; maintaining the magnetic field application state, and irradiating with an ultraviolet light source with a wavelength of 365 nm and an illumination intensity of 500 to 1000 mW / cm2 for 60 to 120 seconds to solidify the slurry in situ to obtain a green body; S5, degassing and sintering. The specific process is: degassing the green body at 600 DEG C for 2 to 4 hours; then increasing the temperature to 880 DEG C to 960 DEG C at a rate of 3 DEG C / min to 5 DEG C / min, and maintaining the temperature for 2 to 6 hours.

[0012] The technical scheme of the present application combines the spatial asymmetric distribution of the auxiliary component with the magnetic field orientation process to realize the following physical and chemical changes during sintering: First, by specifically loading copper oxide on the surface of the ferriferrous bismuth oxide template and distributing bismuth oxide in the matrix, the starting position of the liquid phase generated during the sintering temperature rise process is limited to the contact interface between the template and the matrix. When the copper oxide on the surface of the template reacts with the bismuth oxide diffused from the matrix to form a copper-bismuth liquid phase, the capillary force generated by the interface liquid phase restricts the spatial displacement and rotation of the ferriferrous bismuth oxide particles, maintaining the ordered structure formed during the magnetic field orientation stage; Secondly, the liquid phase channel at the interface establishes a material transmission path from the substrate to the interior of the template, promoting the diffusion of bismuth ions and barium titanate in the substrate to the interior of the bismuth-deficient magnetite dibismuth template. After the bismuth ions and barium titanate are absorbed by the magnetite dibismuth lattice, in-situ topological chemical transformation occurs, generating a bismuth ferrite-barium titanate solid solution with a perovskite structure, and inheriting the orientation characteristics of the precursor template; Finally, as the reaction time is prolonged, the copper ions in the liquid phase diffuse into the B site of the perovskite lattice, and the bismuth ions enter the A site, and the liquid phase components are absorbed by the host lattice, realizing the glass-free densification at the grain boundary.

[0013] The application provides a bismuth ferrite-barium titanate textured piezoelectric ceramic material with low sintering temperature and high piezoelectric performance and a preparation method thereof. 1. The bismuth ferrite precursor template loaded with copper oxide on the surface in the application enables the liquid phase sintering aid to be concentratedly distributed at the solid-solid interface, and in the sintering process, the capillary force generated by the liquid phase at the interface can anchor the template particles, limiting the rotation of the template particles in the densification rearrangement stage, so that the orientation structure induced by the magnetic field is retained. This interface liquid phase regulation mechanism avoids the template deorientation phenomenon caused by the random distribution of the sintering aid in the traditional mixing mode, and improves the texture degree and piezoelectric performance of the ceramic material.

[0014] 2. The interface liquid phase assisted reaction sintering process in the application reduces the densification temperature of the bismuth ferrite-barium titanate ceramic to below 1000 DEG C, and the low-temperature sintering environment inhibits the volatilization of bismuth elements at high temperatures, reduces the generation of oxygen vacancy defects in the lattice, thereby reducing the leakage current density of the material and improving the breakdown field strength, solving the problem that the leakage current is too large to cause the material to be unable to be saturated polarized in the traditional high-temperature solid-phase sintering, so that the prepared textured ceramic has high piezoelectric constant and high insulation resistivity.

[0015] 3. The hyperbranched polyester amide dispersant is used to improve the dispersion state of the multi-component mixed powder in the photosensitive resin in the application, and the unique hyperbranched structure of the dispersant effectively reduces the slurry viscosity while ensuring high solid content, reduces the resistance of the template particles when rotating in the magnetic field, and the improvement of the uniformity of the slurry eliminates the agglomeration and micro-pore defects in the green body, further improving the uniformity of the ceramic microstructure and the mechanical quality factor. DETAILED DESCRIPTION

[0016] All other embodiments obtained by those skilled in the art on the basis of the embodiments in the application without creative labor are within the protection scope of the application.

[0017] EMBODIMENT Embodiment 1 The embodiment provides a preparation method of a bismuth ferrite-barium titanate textured piezoelectric ceramic material with low sintering temperature and high piezoelectric performance. The specific steps are as follows: S1, preparing a ceramic slurry, first, preparing a photosensitive resin premix, mixing monomers HDDA and crosslinking agent TMPTA at a mass ratio of 9:1, adding a photoinitiator TPO accounting for 2% of the total mass of the monomers, and stirring and dissolving; weighing 22.5 g of pre-synthesized barium titanate powder and 27.5 g of bismuth oxide powder, dispersing them in 20 g of the above-mentioned photosensitive resin premix, and adding 1.0 g of the hyperbranched polyester amide dispersant HPEA-2 prepared in Preparation Example 2; finally, adding 47.5 g of the bismuth ferrite precursor template CuO@Bi2Fe4O9-2 loaded with copper oxide on the surface prepared in Preparation Example 5; placing the mixture in a ball mill tank, using zirconium oxide balls as grinding media, ball milling the mixture for 18 hours, and removing bubbles in a vacuum to obtain a ceramic slurry.

[0018] S2, magnetic field orientation and solidification, injecting the ceramic slurry prepared in step S1 into a non-magnetic mold, placing it in an 8T static strong magnetic field generated by a superconducting magnet, and standing for 8 minutes to orient the template; maintaining the magnetic field application state, irradiating the slurry with a UV point light source with a wavelength of 365 nm and an intensity of 800 mW / cm ² for 90 seconds to solidify the slurry in situ, and demolding to obtain a green body.

[0019] S3, degassing and sintering, placing the green body in a tube furnace, heating to 600 DEG C at a rate of 0.8 DEG C / min, and keeping the temperature for 3 hours to perform degassing; then heating to 920 DEG C at a rate of 4 DEG C / min, and keeping the temperature for 4 hours to perform reaction sintering; during the sintering process, the copper oxide on the surface of the template preferentially forms a liquid phase with the diffused bismuth oxide of the matrix at the interface, inducing the template to transform into bismuth ferrite-barium titanate textured grains; and obtaining a bismuth ferrite-barium titanate textured piezoelectric ceramic material after cooling.

[0020] Embodiment 2: The embodiment provides a preparation method of a bismuth ferrite-barium titanate textured piezoelectric ceramic material with low sintering temperature and high piezoelectric performance. The specific steps are as follows: S1, preparing a ceramic slurry, first, preparing a photosensitive resin premix, mixing monomers HDDA and crosslinking agent TMPTA at a mass ratio of 9:1, adding a photoinitiator TPO accounting for 2% of the total mass of the monomers, and stirring and dissolving; weighing 22.5 g of pre-synthesized barium titanate powder and 27.5 g of bismuth oxide powder, dispersing them in 20 g of the above-mentioned photosensitive resin premix, and adding 1.0 g of the hyperbranched polyester amide dispersant HPEA-2 prepared in Preparation Example 2; finally, adding 47.5 g of the bismuth ferrite precursor template CuO@Bi2Fe4O9-2 loaded with copper oxide on the surface prepared in Preparation Example 5; placing the mixture in a ball mill tank, using zirconium oxide balls as grinding media, ball milling the mixture for 18 hours, and removing bubbles in a vacuum to obtain a ceramic slurry.

[0021] S2, magnetic field orientation and solidification, the ceramic slurry is injected into the mold, placed in a 6T static strong magnetic field, and left for 5 minutes. The magnetic field is maintained, and a wavelength of 365nm, intensity of 500mW / cm 2 of ultraviolet light source is irradiated for 60 seconds for solidification, and the green body is demolded.

[0022] S3, glue removal and sintering, the green body is heated to 600℃ at a rate of 0.5℃ / min, and kept for 2 hours for glue removal. Then it is heated to 880℃ at a rate of 3℃ / min, and kept for 2 hours for sintering. By using the low-temperature interfacial liquid phase reaction mechanism, the textured bismuth ferrite-barium titanate piezoelectric ceramic material is obtained.

[0023] Example 3: The embodiment provides a preparation method of a textured bismuth ferrite-barium titanate piezoelectric ceramic material with low sintering temperature and high piezoelectric performance, comprising the following steps: The specific steps are as follows: S1, preparation of ceramic slurry, preparation of photosensitive resin premix, mixing monomer HDDA and crosslinking agent TMPTA at a mass ratio of 10:1, adding 3% of the total mass of monomer as a photoinitiator TPO. 25g of pre-synthesized barium titanate powder, 30g of bismuth oxide powder, 25g of the above photosensitive resin premix, 1.5g of the hyperbranched polyester amide dispersant HPEA-3 prepared in preparation example 3. Finally, 50g of the bismuth ferrite precursor template CuO@Bi2Fe4O9-3 prepared in preparation example 6 is added. The mixture is mixed by ball milling for 24 hours, and vacuum degassing is performed to obtain the ceramic slurry.

[0024] S2, magnetic field orientation and solidification, the ceramic slurry is injected into the mold, placed in a 6T static strong magnetic field, and left for 5 minutes. The magnetic field is maintained, and a wavelength of 365nm, intensity of 500mW / cm 2 of ultraviolet light source is irradiated for 60 seconds for solidification, and the green body is demolded.

[0025] S3, glue removal and sintering, the green body is heated to 600℃ at a rate of 0.5℃ / min, and kept for 2 hours for glue removal. Then it is heated to 880℃ at a rate of 3℃ / min, and kept for 2 hours for sintering. By using the low-temperature interfacial liquid phase reaction mechanism, the textured bismuth ferrite-barium titanate piezoelectric ceramic material is obtained.

[0026] Example 4: The embodiment provides a preparation method of a textured bismuth ferrite-barium titanate piezoelectric ceramic material with low sintering temperature and high piezoelectric performance, comprising the following steps: S1, Preparation of ceramic slurry, photosensitive resin premix and dispersant formula same as example 1. Adjust the proportion of solid powder: take 21 g of pre-synthesized barium titanate powder, 26 g of bismuth oxide powder, add 20 g of photosensitive resin premix and 1.0 g of dispersant HPEA-2. Add 48 g of CuO@Bi2Fe4O9-2 surface-loaded copper oxide bismuth ferrite precursor template prepared in preparation example 5. Ball mill for 20 hours, and remove bubbles.

[0027] S2, magnetic field orientation and curing. Process same as example 1 (8T magnetic field, 8 minutes orientation, 90 seconds curing).

[0028] S3, glue removal and sintering, process same as example 1 (920℃ sintering, 4 hours holding). Get bismuth ferrite-barium titanate textured piezoelectric ceramic material.

[0029] Comparative example Comparative example 1: Compared with example 1, the difference is that the surface-loaded copper oxide bismuth ferrite precursor template is not used. The specific adjustment is: in the slurry preparation of step S1, use equal mass of pure rod-shaped bismuth ferrite oxide powder instead of CuO@Bi2Fe4O9-2 template; At the same time, add the same molar amount of copper nitrate as the surface loading amount of the template in example 1 directly into the photosensitive resin premix, so that it is dispersed in the liquid phase matrix together with bismuth oxide powder and barium titanate powder, thereby simulating the random distribution state of copper oxide additives in the matrix, and the rest of the raw material types, amount and preparation process parameters are the same as example 1.

[0030] Comparative example 2: Compared with example 1, the difference is that the magnetic field orientation process in step S2 is omitted. The specific adjustment is: after the ceramic slurry is injected into the mold, it is not placed in a static strong magnetic field, but directly subjected to ultraviolet light irradiation and curing, and the rest of the raw material types, amount and preparation process parameters are the same as example 1.

[0031] Comparative example 3: Compared with example 1, the difference is that the sintering process uses traditional high-temperature solid-phase sintering, and no copper oxide additive is added. The specific adjustment is: in step S1, use equal mass of pure rod-shaped bismuth ferrite oxide powder instead of CuO@Bi2Fe4O9-2 template, and no additional copper source is added in the slurry; In step S3, the sintering temperature is increased to 1050℃, and the rest of the raw material types, amount and preparation process parameters are the same as example 1.

[0032] Comparative example 4: Compared with Example 1, the difference is that a commercially available ordinary dispersant is used instead of the self-made hyperbranched polyester amide dispersant. The specific adjustment is that in step S1, an equal mass of a commercially available phosphate ester dispersant is used instead of HPEA-2, and the remaining raw material types, amounts, and process parameters are the same as in Example 1.

[0033] Comparative Example 5: Compared with Example 1, the difference is that the loading method of copper oxide is different. The specific adjustment is that in step S1, the nano copper oxide particles are first mixed with pure rod-shaped Bi2Fe4O9-2 powder by high-energy ball milling, trying to attach copper oxide to the surface of the template by physical and mechanical force, and the mixed powder is used instead of the core-shell structure CuO@Bi2Fe4O9-2 template prepared by in-situ chemical precipitation. The remaining raw material types, amounts, and process parameters are the same as in Example 1.

[0034] Test Example Test Example 1: Material density and micro-orientation degree characterization Experimental Steps The sintered ceramic samples prepared in Examples 1 to 4 and Comparative Examples 1 to 5 were tested for density. Archimedes drainage method was used to measure the bulk density of the samples with deionized water as the medium, and the relative density was calculated based on the theoretical density. Subsequently, crystal structure and orientation degree analysis was performed, and the sample surface parallel to the magnetic field direction was scanned using an X-ray diffractometer with a scan range of 2θ of 20° to 60°. Based on the XRD spectrum data, the (001) and (100) diffraction peak intensities were selected, and the Lotgering factor method was used to calculate the texture degree (F), with the formula being wherein is the diffraction peak intensity ratio of the textured sample, is the corresponding intensity ratio of the non-oriented standard powder sample.

[0035] Experimental Data: Table 1 Density and texture degree test results of samples of each example and comparative example

[0036] Conclusion Analysis Table 1 data shows that the relative density of samples of Examples 1 to 4 is higher than 93%, and the Lotgering factor is maintained between 86% and 94%. Example 1 uses a core-shell structure template, which concentrates copper oxide at the interface between the template and the matrix. The capillary force generated by the local liquid phase formed during the sintering process effectively anchors the template particles, limiting their rotation during the rearrangement stage, thereby preserving the ordered structure formed by magnetic field orientation, and finally the Lotgering factor reaches 92.4%.

[0037] In Comparative Example 1, copper oxide was dispersed in the matrix, and the liquid phase was randomly distributed within the matrix, failing to form an effective wetting layer and anchoring effect at the template interface. This resulted in template deflection during densification, reducing the texture to 63.5%. In Comparative Example 2, no magnetic field was applied, and the grains were randomly arranged, with a lotgering factor of only 12.4%. Comparative Example 3 used high-temperature sintering, and the volatilization of bismuth oxide led to increased porosity, reducing the relative density to 88.2%. Comparative Example 5 introduced copper oxide through physical ball milling. Due to uneven coating, the interfacial reaction control was weaker than that of the chemical in-situ precipitation method, resulting in a lower texture than in Example 1. The data indicate that the spatial distribution of the interfacial liquid phase directly affects the final density and orientation of the ceramic.

[0038] Test Example 2: Characterization of Electrical Performance Parameters Experimental steps The sintered ceramic sample was polished and cleaned, coated with silver electrodes on both sides, and placed in a 120℃ silicone oil bath. A DC electric field of 3-4 kV / mm was applied for polarization for 20 minutes. After removal, it was allowed to stand for 24 hours for aging treatment. Quasi-static aging was then performed. The piezoelectric constant of the sample was measured using a measuring instrument. The dielectric constant and dielectric loss were measured at 1 kHz using a precision impedance analyzer, and the planar electromechanical coupling coefficient and mechanical quality factor were calculated using the resonance-anti-resonance method. The hysteresis loop and leakage current density under a 50 kV / cm electric field were measured using a ferroelectric analyzer. The Curie temperature was determined by measuring the change in dielectric constant with temperature.

[0039] Experimental data: Table 2. Test results of piezoelectric, dielectric, and ferroelectric properties of each embodiment and comparative sample.

[0040] Conclusion Analysis Table 2 shows the test results for the piezoelectric constants of samples from Examples 1 to 4. Between 168 and 191 pC / N, with a leakage current density of 10. -6 A / cm 2 Order of magnitude. Example 1 The value is 185 pC / N, which is higher than 85 pC / N in Comparative Example 2. This indicates that the high texture causes the grains to be preferentially oriented along the polarization axis, which increases the effective domain wall density and the sum of spontaneous polarization vectors, thereby improving the material's response to electric fields.

[0041] The dielectric loss and leakage current density of Example 1 are both lower than those of Comparative Example 1. Example 1 utilizes the interfacial liquid phase diffusion mechanism to promote the solidification of copper ions into the crystal lattice, reducing the residual low-resistivity impurity phase at the grain boundaries and increasing the grain boundary resistivity. In Comparative Example 1, due to the random distribution of additives, the locally rich copper liquid phase leads to abnormal grain growth, insufficient densification in the liquid-deficient region, and the easy retention of conductive phase at the grain boundaries, increasing the leakage current.

[0042] Comparative Example 3 was sintered at 1050℃, and the volatilization of bismuth elements resulted in a large number of oxygen vacancies in the crystal lattice, which greatly improved the conductivity as carriers, and the leakage current density reached 452 / cm 2 , which caused the sample to be unable to be effectively polarized. Example 3 appropriately increased the sintering temperature, promoted the development of the crystal lattice, and improved the mechanical quality factor, while the leakage current was still maintained at a low level, indicating that the temperature range defined in the present application can balance the contradiction between densification and component volatilization.

[0043] The method of the present embodiment can be used to perform the above-mentioned method embodiments, which have similar principles and technical effects, and will not be described here again.

Claims

1. A textured piezoelectric ceramic material of bismuth ferrite-barium titanate that combines low sintering temperature and high piezoelectric performance, characterized in that, The following raw material components are included by weight: 20-25 parts of pre-synthesized barium titanate powder, 25-30 parts of bismuth oxide powder, 45-50 parts of bismuth ferrite precursor template with copper oxide loaded on the surface, 0.5-1.5 parts of hyperbranched polyesteramide dispersant, and 15-25 parts of photosensitive resin premix. The bismuth ferrite precursor template with copper oxide loaded on its surface is a core-shell composite powder with copper oxide nanoparticles adsorbed on the surface of rod-shaped bismuth nonoxide particles.

2. The bismuth ferrite-barium titanate textured piezoelectric ceramic material according to claim 1, which combines low sintering temperature and high piezoelectric performance, is characterized in that... The photosensitive resin premix is ​​composed of 1,6-hexanediol diacrylate, trimethylolpropane triacrylate and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; The mass ratio of 1,6-hexanediol diacrylate to trimethylolpropane triacrylate is 8:1 to 10:1, and the amount of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide added is 1% to 3% of the total mass of the monomers.

3. The bismuth ferrite-barium titanate textured piezoelectric ceramic material according to claim 1, which combines low sintering temperature and high piezoelectric performance, is characterized in that... In the bismuth ferrite precursor template with surface-loaded copper oxide, the amount of copper oxide loaded is 0.5% to 3.0% of the total molar amount of the bismuth ferrite-barium titanate textured piezoelectric ceramic material, based on the molar amount of copper.

4. The bismuth ferrite-barium titanate textured piezoelectric ceramic material according to claim 1, which combines low sintering temperature and high piezoelectric performance, is characterized in that... The hyperbranched polyesteramide dispersant is prepared by ring-opening reaction and melt polycondensation reaction of diethanolamine and succinic anhydride at a molar ratio of 1.0:1.0 to 1.2:1.

0.

5. A method for preparing a bismuth ferrite-barium titanate textured piezoelectric ceramic material that combines low sintering temperature and high piezoelectric performance, used to prepare the bismuth ferrite-barium titanate textured piezoelectric ceramic material as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Rod-shaped bismuth nonoxide (Fe₄O₈) powder was synthesized using the molten salt method. S2. A copper source precipitate is grown in situ on the surface of the rod-shaped bismuth ferrooxide powder, and after calcination, the bismuth ferrite precursor template with copper oxide loaded on the surface as described in claim 1 is obtained. S3. Disperse the pre-synthesized barium titanate powder and the bismuth oxide powder in the photosensitive resin premix containing the hyperbranched polyesteramide dispersant, and then add the bismuth ferrite precursor template with copper oxide loaded on its surface, and mix evenly to obtain a ceramic slurry. S4. The ceramic slurry is injected into the mold, oriented under a static magnetic field, and then photocured in situ while the magnetic field is applied to obtain a green body. S5. The green blank is subjected to debinding treatment, and then sintered at 880°C to 960°C. The liquid phase preferentially formed at the interface between the copper oxide on the surface of the copper oxide-loaded bismuth ferrite precursor template and the bismuth oxide diffused in the matrix induces a topological transformation reaction in the copper oxide-loaded bismuth ferrite precursor template to obtain a bismuth ferrite-barium titanate textured piezoelectric ceramic material.

6. The method for preparing a textured piezoelectric ceramic material of bismuth ferrite-barium titanate with both low sintering temperature and high piezoelectric performance according to claim 5, characterized in that, The specific process of step S1 is as follows: The ingredients are prepared by mixing bismuth oxide and iron oxide in a molar ratio of 1:2, adding a molten salt mixture of sodium chloride and potassium chloride in a mass ratio of 1:1, and keeping it at 800°C to 900°C for 4 to 8 hours. After washing and drying, the rod-shaped bismuth nonoxide-iron powder is obtained.

7. The method for preparing a textured piezoelectric ceramic material of bismuth ferrite-barium titanate with both low sintering temperature and high piezoelectric performance according to claim 5, characterized in that, The specific process of step S2 is as follows: The rod-shaped bismuth suboxide (Fe₄O₈) powder was dispersed in a copper nitrate solution with a concentration of 0.05 mol / L to 0.2 mol / L, and urea was added as a precipitant. The mixture was reacted at a constant temperature of 90°C to 95°C for 2 to 4 hours. After separation and drying, the mixture was calcined at 450°C to 500°C for 2 hours.

8. The method for preparing a textured piezoelectric ceramic material of bismuth ferrite-barium titanate with both low sintering temperature and high piezoelectric performance according to claim 5, characterized in that, The preparation method of the hyperbranched polyesteramide dispersant in step S3 is as follows: Diethanolamine and succinic anhydride were mixed and reacted at 140°C to 150°C for 2 to 3 hours. Then the temperature was raised to 160°C to 170°C and polycondensation was carried out under a vacuum of -0.08 MPa to -0.09 MPa for 4 to 6 hours.

9. The method for preparing a textured piezoelectric ceramic material of bismuth ferrite-barium titanate with both low sintering temperature and high piezoelectric performance according to claim 5, characterized in that, In step S4, the magnetic induction intensity of the static magnetic field is 6 Tesla to 10 Tesla, and the orientation time is 5 minutes to 10 minutes. The in-situ photocuring uses an ultraviolet light source with a wavelength of 365 nanometers, an irradiation intensity of 500 milliwatts per square centimeter to 1000 milliwatts per square centimeter, and an irradiation time of 60 seconds to 120 seconds.

10. The method for preparing a textured piezoelectric ceramic material of bismuth ferrite-barium titanate with both low sintering temperature and high piezoelectric performance according to claim 5, characterized in that, In step S5, the temperature of the glue removal process is 600 degrees Celsius, and the heat preservation time is 2 to 4 hours. The heating rate during the sintering process is 3 to 5 degrees Celsius per minute, and the holding time at the sintering temperature is 2 to 6 hours.

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