阅读说明：本技术 一种高居里点低温共烧压电陶瓷配方及制备方法 (Formula and preparation method of high Curie point low temperature co-fired piezoelectric ceramic ) 是由 余方云 李红元 张秀琴 刘如峰 龙阳 邱俊 于 2020-05-22 设计创作，主要内容包括：本发明属于压电陶瓷片技术领域,具体涉及一种高居里点低温共烧压电陶瓷配方及制备方法,包括主体成分和助烧成分,主体成分的组成式为PbaCa1-a[(Mn1/3Sb2/3)x(Zn1/3Nb2/3)y(Zr0.5Ti0.5)z]O3+bwt％Ba(Mg1/2W1/2)O3+cwt％LiNbO3,其中a＝0.02-0.05,x＝0.01-0.06,y＝0.1-0.4,z＝0.89-0.54,b＝0.1-0.25,c＝0.1-0.2,助烧成分包括占主体成分质量比0.1wt％-0.25wt％的玻璃相钨镁酸钡、占主体成分质量比0.1wt％-0.2wt％的铌酸锂,在主体成分PMS-PZN-PZT(锑锰-铌锌-锆钛酸铅)的基础上,掺杂钙钛矿结构的玻璃相钨镁酸钡(Ba(Mg<Sub>1/</Sub><Sub>2</Sub>W<Sub>1/2</Sub>)O<Sub>3</Sub>)及铌酸锂(LiNbO<Sub>3</Sub>),得到烧结温度低于900℃、压电性能好、机电耦合系数高、居里温度高、介电常数大的的压电陶瓷,并且压电陶瓷的配方具有软硬可调的优点,扩大了应用范围。(The invention belongs to the technical field of piezoelectric ceramic pieces, and particularly relates to a formula and a preparation method of high-Curie-point low-temperature co-fired piezoelectric ceramic, which comprises a main component and a sintering-aid component, wherein the main component has a composition formula of PbaCa1-a [ (Mn1/3Sb2/3) x (Zn1/3Nb2/3) y (Zr0.5Ti0.5) z]O3+ bwt% Ba (Mg1/2W1/2) O3+ cwt% LiNbO3, wherein a is 0.02-0.05, x is 0.01-0.06, y is 0.1-0.4, z is 0.89-0.54, b is 0.1-0.25, c is 0.1-0.2, the sintering aid component comprises glass phase barium tungstate 0.1-0.25 wt% of the mass ratio of the main component, lithium niobate 0.1-0.2 wt% of the mass ratio of the main component, and the sintering aid component comprises glass phase barium tungstate 0.1-0.25 wt% of the mass ratio of the main component, lithium niobate 0.1-0.2 wt% of the mass ratio of the main componentBased on PMS-PZN-PZT (antimony manganese-niobium zinc-lead zirconate titanate) as a bulk component, doping a glass phase barium magnesium tungstate (Ba (Mg) with a perovskite structure 1/ 2 W 1/2 )O 3 ) And lithium niobate (LiNbO) 3 ) The piezoelectric ceramic with sintering temperature lower than 900 ℃, good piezoelectric property, high electromechanical coupling coefficient, high Curie temperature and large dielectric constant is obtained, and the formula of the piezoelectric ceramic has the advantages of adjustable hardness and expanded application range.)

1. A formula of a high Curie point low temperature co-fired piezoelectric ceramic is characterized by comprising a main component and a sintering-assistant component,

the composition formula of the main component is PbaCa1-a [ (Mn1/3Sb2/3) x (Zn1/3Nb2/3) y (Zr0.5Ti0.5) z ] O3+ bwt% Ba (Mg1/2W1/2) O3+ cwt% LiNbO3, wherein a is 0.02-0.05, x is 0.01-0.06, y is 0.1-0.4, z is 0.89-0.54, b is 0.1-0.25, c is 0.1-0.2,

the sintering aid component comprises glass-phase barium magnesium tungstate accounting for 0.1-0.25 wt% of the mass ratio of the main component and lithium niobate accounting for 0.1-0.2 wt% of the mass ratio of the main component.

2. The formulation of claim 1, wherein the main component comprises PbO, CaCO₃、Sb₂O₃、Nb₂O₅、ZrO₂、TiO₂、MnCO₃、ZnO。

3. The formulation of claim 2, wherein the PbO is chemically pure CaCO₃、Sb₂O₃、Nb₂O₅、ZrO₂、TiO₂、MnCO₃ZnO was analytically pure.

4. The formulation of claim 1, wherein the composition formula of the main component is PbaCa1-a [ (Mn1/3Sb2/3) x (Zn1/3Nb2/3) y (zr0.5ti0.5) z ] O3+ bmt% Ba (Mg1/2W1/2) O3+ cwt% LiNbO3, wherein a is 0.04, x is 0.045, y is 0.3, z is 0.655, b is 0.1, and c is 0.2, the glass-phase barium tungstate accounts for 0.1 wt% of the mass ratio of the main component, and the lithium niobate accounts for 0.2 wt% of the mass ratio of the main component.

5. A preparation method of high Curie point low temperature co-fired piezoelectric ceramic is characterized by comprising the following steps:

s1: preparation of Ba (Mg)_1/2W_1/2)O₃Pre-sintered powder

According to the formula Ba (Mg)_1/2W_1/2)O₃Weighing analytically pure BaCO₃、Mg(CH₃COO)₂·6H₂O、WO₃Submicron powder, mixing and ball-milling the raw materials for 6-8h under the condition of taking ethanol as a dispersing agent, drying to obtain a precursor of the reaction, then putting the mixed powder into an alumina crucible, presintering for 2h at 750 ℃, and ball-milling and crushing for 6 h;

s2: preparation of LiNbO₃Pre-sintered powder

According to the chemical formula LiNbO₃Weighing analytically pure LiCO₃、Nb₂O₅Sub-micron powder is prepared through mixing the said materials, ball milling for 10 hr, stoving, pre-sintering in alumina crucible at 730 deg.c for 2 hrBall milling and crushing for 8 hours;

s3: ingredients

Raw materials are mixed according to the composition formula PbaCa1-a [ (Mn1/3Sb2/3) x (Zn1/3Nb2/3) y (Zr0.5Ti0.5) z]O₃+bwt％Ba(Mg1/2W1/2)O3+cwt％LiNbO₃Wherein a is 0.02-0.05, x is 0.01-0.06, y is 0.1-0.4, z is 0.89-0.54, b is 0.1-0.25, c is 0.1-0.2, PbO, CaCO are weighed₃、Sb₂O₃、Nb₂O₅、ZrO₂、TiO₂、MnCO₃And ZnO are mixed to prepare a main component, wherein PbO is chemically pure, other raw materials are analytically pure,

weighing Ba (Mg) obtained in step S1 in an amount of 0.1-0.25 wt% based on the mass of the main component_1/2W_1/2)O₃Weighing the LiNbO obtained in the step S2 according to the mass ratio of 0.1-0.2 wt% of the main component₃，

Mixing the prepared main components and weighed Ba (Mg)_1/2W_1/2)O₃、LiNbO₃Placing a mixture in a ball milling tank, and ball in the ball milling tank: material preparation: the weight ratio of water is 2: 1: 0.5, ball milling for 6-8h, and drying the mixed powder after ball milling;

s4: synthesis of

Placing the dried mixed powder obtained in the step S3 into an alumina crucible, compacting and compacting, covering and sealing, and synthesizing for 2h at the temperature of 760-780 ℃ to obtain a synthetic material;

s5: shaping and plastic discharge

Ball-milling and drying the synthetic material obtained in the step S4 again, adding 5 wt% of polyvinyl alcohol aqueous solution for granulation and pressing into a large block, aging the large block blank for 48h, grinding and granulating, sieving the particles with a 100-mesh sieve, molding the obtained sieve material with a mold with the diameter of 10mm under the pressure of 8-10MPa to obtain a blank with the thickness of 2.1mm, heating the blank to 200 ℃ at the speed of 3 ℃/min, heating from 200 ℃ to 400 ℃ at the speed of 1.5 ℃/min, preserving heat at 400 ℃ for 30min, heating to 650 ℃ at the speed of 5 ℃/min, preserving heat for 10min, and discharging organic matters;

s6: sintering

Burying and burning the green body of the organic matter discharged in the step S5 by adopting lead zirconate titanate powder, heating to 870-900 ℃ at the speed of 3 ℃/min in a box-type furnace, preserving heat for 70min, and cooling along with the furnace;

s7: silver firing

Polishing the piezoelectric ceramic plate sintered in the step S6 to the thickness of 2mm, printing silver paste on the upper surface and the lower surface of the piezoelectric ceramic plate by adopting a screen printing process, placing the piezoelectric ceramic plate in a heating furnace, heating to 800 ℃, preserving heat for 12min, and naturally cooling to room temperature;

s8: polarization of

Polarizing the silver-fired product obtained in the step S7 to obtain a piezoelectric ceramic piece, wherein the polarizing temperature is 100-140 ℃, the polarizing time is 20min, and the polarizing electric field is 2-3.5 KV/mm;

s9: testing piezoelectric performance

And (5) standing the piezoelectric ceramic piece subjected to polarization treatment in the step S8 at room temperature for 24 hours, and then testing the piezoelectric performance of the piezoelectric ceramic piece, and simultaneously testing the XRD (X-ray diffraction) pattern and the SEM (scanning Electron microscope) pattern of the sintered ceramic.

Technical Field

The invention belongs to the technical field of piezoelectric ceramic pieces, and particularly relates to a formula and a preparation method of a high-Curie-point low-temperature co-fired piezoelectric ceramic.

Background

The traditional lead-based piezoelectric ceramic has a high sintering temperature of generally 1200-1300 ℃, and can cause PbO to be seriously volatilized during high-temperature sintering, the volatilization of PbO not only causes the stoichiometric ratio of the ceramic to deviate from the originally designed formula, but also can cause environmental pollution and harm human health, and meanwhile, along with the development of Internet of things, artificial intelligence, 5G networks and the like, the piezoelectric ceramic gradually turns to the development of chip type, multilayer, thick film and thin film from a block preparation process. The benchmarking enterprises in the foreign piezoelectric industry, such as PI, CeramTec, Murata, Kyocera and the like, invest a lot of capital in a series to develop piezoelectric stacks, piezoelectric actuators, vibrating motors, loudspeakers, piezoelectric micro-shifters and the like, which belong to the multilayer piezoelectric ceramic co-firing technology, have wide application in various industries, particularly in the field of high precision, are high in price and are in monopoly status.

In order to break the monopoly of the market, the development of low-cost high-performance multilayer chip piezoelectric ceramics is called as a requirement of industry development. The multilayer co-firing requires a metal electrode as an internal electrode, and expensive Pd or Ag-Pd is generally selected due to the high sintering temperature of the conventional piezoelectric ceramics. In order to reduce the cost and reduce the sintering and ceramic forming temperature of the ceramic, the pure silver palladium-free inner electrode sintering becomes the research direction of each mechanism.

Since the melting point of the silver molecules is 960 ℃, the conventional silver electrode sintering safety temperature is below 900 ℃ in consideration of the activity and silver migration state of the silver molecules. Therefore, the sintering temperature of the piezoelectric ceramic main body formula is required to be lower than 900 ℃ to realize the co-firing of the silver electrode.

Some domestic research institutions report formulations below 900 ℃, mainly aiming at modifying and doping a main body PZN-PNN-PZT (niobium zinc-niobium nickel-lead zirconate titanate) by CuO/LiCO3/SiO2 and the like, because more sintering aids are doped, the piezoelectric performance is not ideal, and because the Curie temperatures of a PZN system and a PNN system are lower, namely 190 ℃ and 130 ℃, respectively, the Curie point of the overall formulation is lower, and the use of the product in a high-temperature environment is influenced. In order to improve the local temperature, some research institutions select BiScO3-PbTiO3 as a main body formula or PbTiO3 as a main body formula, and modify the main body formula to obtain a formula with a high Curie point.

Some mechanisms adopt special processes, such as a chemical powder preparation method for increasing powder activity, a hot pressing method, a microwave-assisted sintering method and the like for promoting sintering, and the process threshold is high, so that the large-scale production is not facilitated.

Disclosure of Invention

The invention aims to solve the technical problem of providing a formula and a preparation method of high-Curie-point low-temperature co-fired piezoelectric ceramic, aiming at the defects, and the formula and the preparation method are characterized in that on the basis of a main component PMS-PZN-PZT (antimony manganese-niobium zinc-lead zirconate titanate), a perovskite-structure-doped glass-phase barium magnesium tungstate (Ba (Mg)_1/2W_1/2)O₃) And lithium niobate (LiNbO)₃) The piezoelectric ceramic with sintering temperature lower than 900 ℃, good piezoelectric property, high electromechanical coupling coefficient, high Curie temperature and large dielectric constant is obtained, and the formula of the piezoelectric ceramic has the advantages of adjustable hardness and expanded application range.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a formula of a high Curie point low temperature co-fired piezoelectric ceramic comprises a main component and a sintering-assistant component,

the composition formula of the main component is PbaCa1-a [ (Mn1/3Sb2/3) x (Zn1/3Nb2/3) y (Zr0.5Ti0.5) z ] O3+ bwt% Ba (Mg1/2W1/2) O3+ cwt% LiNbO3, wherein a is 0.02-0.05, x is 0.01-0.06, y is 0.1-0.4, z is 0.89-0.54, b is 0.1-0.25, c is 0.1-0.2,

the sintering aid component comprises glass-phase barium magnesium tungstate accounting for 0.1-0.25 wt% of the mass ratio of the main component and lithium niobate accounting for 0.1-0.2 wt% of the mass ratio of the main component.

Further, the main body component comprises PbO and CaCO₃、Sb₂O₃、Nb₂O₅、ZrO₂、TiO₂、MnCO₃、ZnO。

Further, the PbO is chemically pure CaCO₃、Sb₂O₃、Nb₂O₅、ZrO₂、TiO₂、MnCO₃ZnO was analytically pure.

Further, the composition formula of the main component is PbaCa1-a [ (Mn1/3Sb2/3) x (Zn1/3Nb2/3) y (zr0.5ti0.5) z ] O3+ bmt% Ba (Mg1/2W1/2) O3+ cwt% LiNbO3, wherein a is 0.04, x is 0.045, y is 0.3, z is 0.655, b is 0.1, and c is 0.2, the glass-phase barium magnesium tungstate accounts for 0.1 wt% of the mass ratio of the main component, and the lithium niobate accounts for 0.2 wt% of the mass ratio of the main component.

A preparation method of a high Curie point low temperature co-fired piezoelectric ceramic comprises the following steps:

s1: preparation of Ba (Mg)_1/2W_1/2)O₃Pre-sintered powder

According to the formula Ba (Mg)_1/2W_1/2)O₃Weighing analytically pure BaCO₃、Mg(CH₃COO)₂·6H₂O、WO₃Submicron powder, mixing and ball-milling the raw materials for 6-8h under the condition of taking ethanol as a dispersing agent, drying to obtain a precursor of the reaction, then putting the mixed powder into an alumina crucible, presintering for 2h at 750 ℃, and ball-milling and crushing for 6 h;

s2: preparation of LiNbO₃Pre-sintered powder

According to the chemical formula LiNbO₃Weighing analytically pure LiCO₃、Nb₂O₅The submicron powder is prepared by mixing and ball-milling the raw materials for 10 hours under the condition of taking distilled water as a dispersing agent, drying, then putting the mixed powder into an alumina crucible, presintering for 2 hours at 730 ℃, and ball-milling and crushing for 8 hours;

s3: ingredients

Raw materials are mixed according to the composition formula PbaCa1-a [ (Mn1/3Sb2/3) x (Zn1/3Nb2/3) y (Zr0.5Ti0.5) z]O₃+bwt％Ba(Mg1/2W1/2)O3+cwt％LiNbO₃Wherein a is 0.02-0.05, x is 0.01-0.06, y is 0.1-0.4, z is 0.89-0.54, b is 0.1-0.25, c is 0.1-0.2, PbO, CaCO are weighed₃、Sb₂O₃、Nb₂O₅、ZrO₂、TiO₂、MnCO₃And ZnO are mixed to prepare a main component, wherein PbO is chemically pure, other raw materials are analytically pure,

weighing Ba (Mg) obtained in step S1 in an amount of 0.1-0.25 wt% based on the mass of the main component_1/2W_1/2)O₃Weighing the LiNbO obtained in the step S2 according to the mass ratio of 0.1-0.2 wt% of the main component₃，

Mixing the prepared main components and weighed Ba (Mg)_1/2W_1/2)O₃、LiNbO₃Placing a mixture in a ball milling tank, and ball in the ball milling tank: material preparation: the weight ratio of water is 2: 1: 0.5, ball milling for 6-8h, and drying the mixed powder after ball milling;

s4: synthesis of

Placing the dried mixed powder obtained in the step S3 into an alumina crucible, compacting and compacting, covering and sealing, and synthesizing for 2h at the temperature of 760-780 ℃ to obtain a synthetic material;

s5: shaping and plastic discharge

Ball-milling and drying the synthetic material obtained in the step S4 again, adding 5 wt% of polyvinyl alcohol aqueous solution for granulation and pressing into a large block, aging the large block blank for 48h, grinding and granulating, sieving the particles with a 100-mesh sieve, molding the obtained sieve material with a mold with the diameter of 10mm under the pressure of 8-10MPa to obtain a blank with the thickness of 2.1mm, heating the blank to 200 ℃ at the speed of 3 ℃/min, heating from 200 ℃ to 400 ℃ at the speed of 1.5 ℃/min, preserving heat at 400 ℃ for 30min, heating to 650 ℃ at the speed of 5 ℃/min, preserving heat for 10min, and discharging organic matters;

s6: sintering

Burying and burning the green body of the organic matter discharged in the step S5 by adopting lead zirconate titanate powder, heating to 870-900 ℃ at the speed of 3 ℃/min in a box-type furnace, preserving heat for 70min, and cooling along with the furnace;

s7: silver firing

Polishing the piezoelectric ceramic plate sintered in the step S6 to the thickness of 2mm, printing silver paste on the upper surface and the lower surface of the piezoelectric ceramic plate by adopting a screen printing process, placing the piezoelectric ceramic plate in a heating furnace, heating to 800 ℃, preserving heat for 12min, and naturally cooling to room temperature;

s8: polarization of

Polarizing the silver-fired product obtained in the step S7 to obtain a piezoelectric ceramic piece, wherein the polarizing temperature is 100-140 ℃, the polarizing time is 20min, and the polarizing electric field is 2-3.5 KV/mm;

s9: testing piezoelectric performance

And (5) standing the piezoelectric ceramic piece subjected to polarization treatment in the step S8 at room temperature for 24 hours, and then testing the piezoelectric performance of the piezoelectric ceramic piece, and simultaneously testing the XRD (X-ray diffraction) pattern and the SEM (scanning Electron microscope) pattern of the sintered ceramic.

The invention has the beneficial effects that: by adopting the scheme, the method has the advantages that,

1. the sintering aid is barium magnesium tungstate and lithium niobate with a perovskite structure, has the same microstructure as the main component, has piezoelectricity, does not damage the piezoelectric property of the main component, and can promote the improvement of the piezoelectric property of a finished product;

2. the Curie temperature of the lithium niobate is 1210 ℃ which is very high, so that the Curie temperature of the formula is successfully improved;

3. magnesium element and lithium element can well reduce the sintering temperature;

4. the lithium niobate has high spontaneous polarization intensity, has a synergistic effect with the main component, is sintered at the temperature lower than 900 ℃, and improves the overall piezoelectric property.

Drawings

The foregoing and other objects, features, and advantages of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings.

FIG. 1 shows Ba (Mg) in example 1 of the present invention_1/2W_1/2)O₃XRD pattern synthesized at 750 ℃;

FIG. 2 shows LiNbO in example 1 of the present invention₃XRD pattern synthesized at 730 deg.C;

FIG. 3 is an XRD pattern of a sintered ceramic according to examples 1 and 2 of the present invention;

FIG. 4 is an SEM photograph of a sintered ceramic in example 1 of the present invention;

FIG. 5 is an SEM photograph of a sintered ceramic in example 2 of the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

A formula of a high Curie point low temperature co-fired piezoelectric ceramic comprises a main component and a sintering-assistant component, wherein the composition formula of the main component is PbaCa1-a [ (Mn1/3Sb2/3) x (Zn1/3Nb2/3) y (Zr0.5Ti0.5) z]O3+ bwt% Ba (Mg1/2W1/2) O3+ cwt% LiNbO3, wherein a is 0.02-0.05, x is 0.01-0.06, y is 0.1-0.4, z is 0.89-0.54, b is 0.1-0.25, c is 0.1-0.2, the main component comprises PbO, CaCO₃、Sb₂O₃、Nb₂O₅、ZrO₂、TiO₂、MnCO₃ZnO, wherein PbO is chemically pure, CaCO₃、Sb₂O₃、Nb₂O₅、ZrO₂、TiO₂、MnCO₃ZnO is analytically pure, and the sintering-aid component comprises glass-phase barium magnesium tungstate accounting for 0.1-0.25 wt% of the mass ratio of the main component and lithium niobate accounting for 0.1-0.2 wt% of the mass ratio of the main component.

Examples of the preparation method of the high Curie point low temperature co-fired piezoelectric ceramic