Temperature-holding stable piezoelectric ceramic material and preparation method thereof

文档序号:1196487 发布日期:2020-09-01 浏览:30次 中文

阅读说明:本技术 一种容温稳定性压电陶瓷材料以及制备方法 (Temperature-holding stable piezoelectric ceramic material and preparation method thereof ) 是由 余方云 李红元 张秀琴 刘如峰 龙阳 邱俊 于 2020-06-05 设计创作,主要内容包括:本发明公开一种容温稳定性压电陶瓷材料以及制备方法,该压电陶瓷材料的组成为xPb(Yb<Sub>0.5</Sub>Nb<Sub>0.5</Sub>)O<Sub>3</Sub>(1-x)Pb(Zr<Sub>0.49</Sub>Ti<Sub>0.51</Sub>)O<Sub>3</Sub>+ywt%Ba<Sub>1-c-d</Sub>Sr<Sub>c</Sub>Mg<Sub>d</Sub>Sn<Sub>a</Sub>Zr<Sub>b</Sub>Ti<Sub>1-a-b</Sub>O<Sub>3</Sub>,其中,x的取值范围为0.02~0.05,y的取值范围为0.5~3,a的取值范围为0.05~0.15,b的取值范围为0.05~0.1,c的取值范围为0.01~0.05,d的取值范围为0.01~0.05。本发明通过在压电陶瓷本体配方中掺杂介电常数随温度升高而降低的组分,以降低压电陶瓷材料介电常数随温度的变化率,制作成本低,易于实现批量生产的容温稳定的压电陶瓷。(The invention discloses a piezoelectric ceramic material with temperature capacity stability and a preparation method thereof, wherein the piezoelectric ceramic material comprises xPb (Yb) 0.5 Nb 0.5 )O 3 (1‑x)Pb(Zr 0.49 Ti 0.51 )O 3 +ywt%Ba 1‑c‑d Sr c Mg d Sn a Zr b Ti 1‑a‑b O 3 Wherein the value range of x is 0.02-0.05, the value range of y is 0.5-3, the value range of a is 0.05-0.15, the value range of b is 0.05-0.1, the value range of c is 0.01-0.05, and the value range of d is 0.01-0.05. The invention reduces the change rate of the dielectric constant of the piezoelectric ceramic material along with the temperature by doping the components with which the dielectric constant is reduced along with the temperature increase in the formula of the piezoelectric ceramic body, has low manufacturing cost and is easy to realize the piezoelectric ceramic with stable temperature capacity in batch production.)

1. A piezoceramic material with temperature stability is characterized in that the piezoceramic material comprises the following materials:

xPb(Yb0.5Nb0.5)O3(1-x)Pb(Zr0.49Ti0.51)O3+ywt%Ba1-c-dSrcMgdSnaZrbTi1-a-bO3

wherein the value range of x is 0.02-0.05, the value range of y is 0.5-3, the value range of a is 0.05-0.15, the value range of b is 0.05-0.1, the value range of c is 0.01-0.05, and the value range of d is 0.01-0.05.

2. A method of preparing the piezoceramic material according to claim 1, comprising the steps of:

step one, preparing Ba1-c-dSrcMgdSnaZrbTi1-a-bO3Pre-sintering powder:

first, pressChemical formula Ba1-c-dSrcMgdSnaZrbTi1-a-bO3Weighing BaCO3、SrCO3、SnO2、Mg2(OH)2CO3、TiO2、ZrO2The powder raw material comprises a powder raw material, wherein the value range of a is 0.05-0.15, the value range of b is 0.05-0.1, the value range of c is 0.01-0.05, and the value range of d is 0.01-0.05; then, grinding, presintering, grinding and crushing the weighed powder raw materials to obtain presintering powder;

step two, batching:

the raw material of the ingredients comprises the weighed main powder material and the pre-sintering powder obtained in the step one; the main powder material comprises chemical formula xpB (Yb) of piezoelectric ceramic main body formula0.5Nb0.5)O3(1-x)Pb(Zr0.49Ti0.51)O3Weighing PbO2、Yb2O3、Nb2O5、ZrO2、TiO2Wherein the value range of x is 0.02-0.05; the weight ratio of the pre-sintering powder to the main components of the raw materials of the ingredients is 0.5-3 wt%; grinding and drying the weighed ingredient raw materials;

step three, synthesis: synthesizing the dried ingredient raw materials in the step two at high temperature to prepare a synthetic material;

step four, molding and plastic removal: molding and plastic removing treatment are carried out on the synthetic material prepared in the third step to obtain an organic matter;

step five, sintering: sintering the green body of the organic matter obtained in the step four to obtain ceramic;

step six, silver burning: firing silver on the ceramic prepared in the fifth step;

step seven, polarization: and polarizing the silver-fired ceramic obtained in the step six under different polarization conditions to obtain the piezoelectric ceramic material.

3. The method for preparing a piezoelectric ceramic material according to claim 2, wherein in the first step, the powder raw material BaCO is weighed3、SrCO3、SnO2、Mg2(OH)2CO3、TiO2And ZrO2The purity of the product is analytically pure, the weighed powder raw materials are mixed and ball-milled for 6-8h in a ball-milling tank under the condition that ethanol is used as a dispersing agent, and a reaction precursor is obtained after drying; and then putting the precursor into an alumina crucible, presintering for 2h at 1050 ℃, and then crushing for 6h through a ball milling tank to obtain presintering powder.

4. The method for preparing a piezoelectric ceramic material according to claim 2, wherein in the second step, the weighed PbO is used2Is chemically pure Yb2O3、Nb2O5、ZrO2、TiO2The purity of (2) for the analytical purity, will weigh the batching raw materials compounding in the ball-milling jar, the ball in the ball-milling jar: powder lot: the weight ratio of water is 2: 1: 0.5, ball milling for 6-8h, and drying the raw materials.

5. The method for preparing a piezoceramic material according to claim 2, wherein in the third step, the raw materials of the ingredients dried in the second step are placed into an alumina crucible for compaction and compaction, and then are covered and sealed, and are synthesized for 2h at 950-.

6. The preparation method of the piezoceramic material according to claim 2, wherein in the fourth step, the synthetic material in the third step is ball-milled and dried again, 5 wt% of polyvinyl alcohol aqueous solution is added for granulation and block blank body pressing, the block blank body is aged for 48h, then crushed, granulated and sieved, particles in the granulation process pass through a 100-mesh sieve to obtain sieve material, the obtained sieve material is molded by a mold with the diameter of 10mm under the pressure of 8-10MPa to obtain a blank body with the thickness of 2.1mm, the blank body is heated to 200 ℃ at the speed of 3 ℃/min, then the temperature is raised from 200 ℃ to 400 ℃ at the speed of 1.5 ℃/min, and after the temperature is preserved for 30min at 400 ℃, the temperature is raised to 650 ℃ at the speed of 5 ℃/min and the temperature is preserved for 10min, and organic matters are discharged.

7. The method for preparing a piezoelectric ceramic material according to claim 2, wherein in the fifth step, the green body of the organic substance discharged from the fourth step is buried and burned by adopting lead zirconate titanate powder, the temperature is raised to 1200-1250 ℃ at the speed of 3 ℃/min in a box-type furnace, the temperature is maintained for 70min, and the green body is cooled along with the box-type furnace to obtain the ceramic.

8. The preparation method of the piezoelectric ceramic material according to claim 2, wherein in the sixth step, the ceramic sintered in the fifth step is ground to a thickness of 2mm, silver paste is printed on the upper and lower surfaces of the ceramic by a screen printing process, and the ceramic is heated at 800 ℃ for 12min to be silver-fired.

9. The method for preparing a piezoceramic material according to claim 2, wherein the polarization temperature in the seventh step is 100-140 ℃, the polarization time is 20min, and the polarization electric field is 2-3.5 KV/mm.

10. The method for preparing a piezoelectric ceramic material according to claim 2, further comprising a step eight of measuring the piezoelectric properties of the piezoelectric ceramic material prepared in the step one to the step seven, measuring the piezoelectric properties after standing at room temperature for 24 hours, measuring the dielectric constant of the piezoelectric ceramic material in a temperature range of-45 ℃ to +125 ℃ using a digital bridge, and calculating the rate of change.

Technical Field

The invention belongs to the technical field of piezoelectric ceramics, and particularly relates to a piezoelectric ceramic material with temperature-holding stability and a preparation method thereof.

Background

Piezoelectric ceramics are widely applied to electroacoustic devices, ultrasonic transducers, acceleration sensors, piezoelectric detonators, sonar, nuclear protection goggles, piezoelectric micro-displacement brakes, piezoelectric actuators and the like since being discovered due to special positive and negative piezoelectric effects of the piezoelectric ceramics. With the development of science and technology and the increasing requirements of various industries on devices, high-performance piezoelectric ceramics are strongly demanded by the market. In particular, in the automotive field and industrial monitoring, the piezoelectric ceramic is required to have good temperature stability, i.e., the smaller the change coefficient of capacitance with temperature is, the better the piezoelectric ceramic is, within the range of-45 ℃ to +125 ℃, so as to ensure that the piezoelectric device still has high sensitivity in harsh high and low temperature environments. To achieve this goal, a great deal of research work has been done by many research institutes and business entities, including: 1. the PZT-based piezoelectric ceramic is prepared by doping or modifying a formula and a process, but the time consumption is long, the difficulty is high, and the variation range of part of Japanese manufacturers is within +/-10%; PZT-based piezoelectric ceramics are ceramics with positive temperature coefficient, a thin layer (0.05-0.1mm) of dielectric ceramics with negative temperature coefficient of capacitance and compensation property is pasted on the surface of the prepared piezoelectric ceramic finished product by glue adhesion process in a series connection mode, and the method has complex process, and the dielectric ceramics are easy to crack and are not easy to produce in large batch; 3. the piezoelectric ceramic is connected in parallel with a capacitor with a negative capacitance temperature coefficient to serve as a compensation capacitor, the compensation capacitor occupies space, the structure is not simplified, other performances of the device are affected, and the device cannot be developed towards miniaturization.

In all the piezoelectric ceramics in the market, the dielectric constant (capacitance) of the piezoelectric ceramics increases with the temperature rise below the curie temperature, and the variation is large, meanwhile, in the field of dielectric ceramic capacitors, in order to obtain the dielectric ceramics with good temperature stability, many manufacturers and researchers dope SrTiO3, CaTiO3, BaTiO3 and the like with certain negative temperature coefficient of capacitance on the basis of the original formula, but the dielectric constants of the dielectric components are lower, generally 300-2000-plus-2000, and cannot meet the requirement of dielectric temperature compensation of the piezoelectric ceramics.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a piezoelectric ceramic material with temperature-holding stability and a preparation method thereof, aiming at the defects of the prior art, the invention adopts a blending technology of a special formula, the formula of a piezoelectric ceramic body is doped with components with dielectric constants reduced along with the temperature rise, and the components are combined to be used as a synthetic body to be doped into the piezoelectric ceramic, so that a piezoelectric ceramic vibrator with good comprehensive performance is obtained, and the temperature-holding change is controlled to be between-5% and + 3% within the range of-45 ℃ and +125 ℃.

The technical scheme for realizing the invention is as follows: the piezoelectric ceramic material comprises the following materials:

xPb(Yb0.5Nb0.5)O3(1-x)Pb(Zr0.49Ti0.51)O3+ywt%Ba1-c-dSrcMgdSnaZrbTi1-a-bO3

wherein the value range of x is 0.02-0.05, the value range of y is 0.5-3, the value range of a is 0.05-0.15, the value range of b is 0.05-0.1, the value range of c is 0.01-0.05, and the value range of d is 0.01-0.05.

A preparation method for preparing the piezoelectric ceramic material comprises the following steps:

step one, preparing Ba1-c-dSrcMgdSnaZrbTi1-a-bO3Pre-sintering powder:

first, according to the formula Ba1-c-dSrcMgdSnaZrbTi1-a-bO3Weighing BaCO3、SrCO3、SnO2、Mg2(OH)2CO3、TiO2、ZrO2The powder raw material comprises a powder raw material, wherein the value range of a is 0.05-0.15, the value range of b is 0.05-0.1, the value range of c is 0.01-0.05, and the value range of d is 0.01-0.05; then, grinding, presintering, grinding and crushing the weighed powder raw materials to obtain presintering powder;

step two, batching:

the raw material of the ingredients comprises the weighed main powder material and the pre-sintering powder obtained in the step one; the main powder material comprises chemical formula xpB (Yb) of piezoelectric ceramic main body formula0.5Nb0.5)O3(1-x)Pb(Zr0.49Ti0.51)O3Weighed PbO2、Yb2O3、Nb2O5、ZrO2、TiO2Wherein the value range of x is 0.02-0.05; the weight ratio of the pre-sintering powder to the main components of the raw materials of the ingredients is 0.5-3 wt%; grinding and drying the weighed ingredient raw materials;

step three, synthesis: synthesizing the dried ingredient raw materials in the step two at high temperature to prepare a synthetic material;

step four, molding and plastic removal: carrying out molding and plastic removal treatment on the synthetic material in the third step to obtain an organic matter;

step five, sintering: sintering the green body of the organic matter in the fourth step to prepare ceramic;

step six, silver burning: firing silver on the ceramic prepared in the fifth step;

step seven, polarization: and polarizing the silver-fired ceramic obtained in the step six under different polarization conditions to obtain the piezoelectric ceramic material.

Further, in the step one, the powder raw material BaCO is weighed3、SrCO3、SnO2、Mg2(OH)2CO3、TiO2And ZrO2The purity of the product is analytically pure, the weighed powder raw materials are mixed and ball-milled for 6-8h in a ball-milling tank under the condition that ethanol is used as a dispersing agent, and a reaction precursor is obtained after drying; then the precursor is put into an alumina crucible and the temperature of the alumina crucible is 1050 DEG CAnd after presintering for 2 hours, crushing for 6 hours by using a ball milling tank to obtain presintering powder, wherein the presintering powder can be obtained by fully grinding and uniformly mixing the weighed powder raw materials and presintering.

Further, in the second step, the weighed PbO is used2Is chemically pure Yb2O3、Nb2O5、ZrO2、TiO2The purity of (2) for the analytical purity, will weigh the batching raw materials compounding in the ball-milling jar, the ball in the ball-milling jar: powder lot: the weight ratio of water is 2: 1: 0.5, the ball milling time is 6-8h, and then the ingredient raw materials are dried, wherein in the operation step, the ingredient raw materials can be fully ground and mixed in a ball milling tank to obtain the dried and uniformly mixed ingredient raw materials.

Further, in the third step, the dried ingredient raw materials in the second step are placed into an alumina crucible for compaction and compaction, and then are covered and sealed, and are synthesized for 2 hours at the temperature of 950-.

Further, in the fourth step, the synthetic material in the third step is subjected to ball milling and drying again, 5 wt% of polyvinyl alcohol aqueous solution is added for granulation and block blank body pressing, the block blank body is aged for 48 hours, then grinding and granulation are carried out, particles in the granulation process pass through a 100-mesh sieve to obtain sieve material, the obtained sieve material is molded by a mold with the diameter of 10mm under the pressure of 8-10MPa to obtain a blank body with the thickness of 2.1mm, the temperature of the blank body is raised to 200 ℃ at the speed of 3 ℃/min, then the temperature is raised from 200 ℃ to 400 ℃ at the speed of 1.5 ℃/min, the temperature is maintained at 400 ℃ for 30min, then the temperature is raised to 650 ℃ at the speed of 5 ℃/min, the temperature is maintained for 10min, and organic matters are discharged.

Further, in the fifth step, the green body of the organic matter discharged in the fourth step is buried and burned by adopting lead zirconate titanate powder, the temperature is raised to 1200-1250 ℃ at the speed of 3 ℃/min in a box-type furnace, the temperature is kept for 70min, and the green body is cooled along with the box-type furnace to obtain the ceramic.

Further, in the sixth step, the ceramic sintered in the fifth step is ground to a thickness of 2mm, silver paste is printed on the upper surface and the lower surface of the ceramic by adopting a screen printing process, and the ceramic is subjected to heat preservation at the temperature of 800 ℃ for 12min for silver firing.

Further, the polarization temperature in the seventh step is 100-140 ℃, the polarization time is 20min, and the polarization electric field is 2-3.5 KV/mm.

And step eight, testing the piezoelectric performance of the piezoelectric ceramic material prepared in the step one to the step seven in the step eight, testing the piezoelectric performance after standing for 24 hours at room temperature, testing the dielectric constant of the piezoelectric ceramic material in the temperature range of-45 ℃ to +125 ℃ by using a digital bridge, and calculating the change rate.

By adopting the technical scheme, the invention has the following beneficial effects:

(1) the invention dopes the component with dielectric constant decreasing with temperature increase in the formula of the piezoelectric ceramic body, and the component adopts Ba1-c-dSrcMgdSnaZrbTi1-a-bO3The piezoelectric ceramic material which has good comprehensive performance and has the capacity temperature change controlled to be-5%. + 3% in the temperature range of-45 ℃ to +125 ℃ is obtained by doping the components serving as a synthetic body according to a certain mass ratio into the piezoelectric ceramic formula, so that the change amplitude of the dielectric constant of the piezoelectric ceramic material in a certain temperature range is reduced, and the piezoelectric ceramic material still has high sensitivity in a harsh high-temperature and low-temperature environment.

(2) The preparation method of the piezoceramic material adopts Ba with the relative dielectric constant peak value as high as 130001-c-dSrcMgdSnaZrbTi1-a-bO3Component, Ba relating to the preparation method of the present invention1-c- dSrcMgdSnaZrbTi1-a-bO3The components are synthesized by a traditional solid phase method, the manufacturing cost is low, the volume production of the piezoelectric ceramic material with stable temperature capacity is easy to realize, and the piezoelectric ceramic material can be widely applied to the fields of piezoelectric ceramics for automobile sensors, piezoelectric ceramics for flowmeters and the like.

(3) The ceramic after silver firing is polarized at the polarization temperature of 100-140 ℃, the polarization time of 20min and the polarization electric field of 2-3.5KV/mm to obtain the piezoelectric ceramic material, and the polarization condition is designed according to the material composition and the size of the ceramic, so that the prepared piezoelectric ceramic material has the optimal piezoelectric property.

(4) The piezoelectric performance of the piezoelectric ceramic material prepared in the first step to the seventh step is tested in the eighth step, the piezoelectric performance of the piezoelectric ceramic material is tested after the piezoelectric ceramic material is kept stand for 24 hours at room temperature, the dielectric constant of the piezoelectric ceramic material in the temperature range of minus 45 ℃ to plus 125 ℃ is tested by using a digital bridge, the change rate is calculated, and the tested experimental data verify whether the final finished piezoelectric ceramic material can achieve the final expected effect or not, so that the quality of the piezoelectric ceramic material is ensured to meet the use requirement.

(5) The powder raw material BaCO weighed in the step one in the invention3、SrCO3、SnO2、Mg2(OH)2CO3、TiO2And ZrO2The purity of the pre-sintered powder is analytically pure, and the high-purity powder raw material can improve the purity of the pre-sintered powder and reduce the influence of impurities.

Detailed Description

The technical solution of the present invention is described in detail below, but the scope of the present invention is not limited to the embodiments.

A co-fired piezoelectric ceramic material with temperature stability comprises the following materials:

xPb(Yb0.5Nb0.5)O3(1-x)Pb(Zr0.49Ti0.51)O3+ywt%Ba1-c-dSrcMgdSnaZrbTi1-a-bO3

wherein the value range of x is 0.02-0.05, the value range of y is 0.5-3, the value range of a is 0.05-0.15, the value range of b is 0.05-0.1, the value range of c is 0.01-0.05, and the value range of d is 0.01-0.05.

A method for preparing the piezoelectric ceramic material comprises the following steps:

step one, preparing Ba1-c-dSrcMgdSnaZrbTi1-a-bO3Pre-sintering powder:

first, according to the formula Ba1-c-dSrcMgdSnaZrbTi1-a-bO3Weighing analytically pure BaCO3、SrCO3、SnO2、Mg2(OH)2CO3、TiO2、ZrO2The powder raw material comprises a powder raw material, wherein the value range of a is 0.05-0.15, the value range of b is 0.05-0.1, the value range of c is 0.01-0.05, and the value range of d is 0.01-0.05; then, mixing and ball-milling the weighed powder raw materials in a ball-milling tank for 6-8h under the condition of an ethanol dispersant, and drying to obtain a precursor of the reaction; then putting the precursor into an alumina crucible, pre-sintering at 1050 ℃ for 2h, and then crushing for 6h by using a ball milling tank to obtain pre-sintered powder, wherein the impurities in the finished pre-sintered powder can be reduced by using high-purity powder raw materials, so that the effect of the pre-sintered powder can be better exerted;

step two, batching:

the raw material of the ingredients comprises the weighed main powder material and the pre-sintering powder obtained in the step one; the main powder material comprises chemical formula xpB (Yb) of piezoelectric ceramic main body formula0.5Nb0.5)O3(1-x)Pb(Zr0.49Ti0.51)O3Weighed PbO2、Yb2O3、Nb2O5、ZrO2、TiO2Wherein the value range of x is 0.02-0.05, PbO2Is chemically pure Yb2O3、Nb2O5、ZrO2、TiO2The purity of the pre-sintering powder is analytically pure, and the weighed amount of the pre-sintering powder accounts for 0.5-3 wt% of the mass ratio of the main components of the raw materials of the ingredients; mixing the weighed ingredients in a ball milling tank, and making balls in the ball milling tank: powder lot: the weight ratio of water is 2: 1: 0.5, ball milling for 6-8h, and drying the ball-milled ingredients;

step three, synthesis:

putting the dried raw material powder in the step two into an alumina crucible, compacting and compacting, covering and sealing, and synthesizing at 950 + 1050 ℃ for 2h to obtain a synthetic material;

step four, molding and plastic removal:

ball-milling and drying the synthetic material obtained in the third step again, adding 5 wt% of polyvinyl alcohol aqueous solution for granulation, pressing a large block blank, aging the large block blank for 48 hours, then grinding, granulating and sieving, sieving the sieved particles with a 100-mesh sieve to obtain a sieve material, 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 the blank to 400 ℃ from 200 ℃ at the speed of 1.5 ℃/min, preserving the heat at 400 ℃ for 30min, heating to 650 ℃ at the speed of 5 ℃/min, preserving the heat for 10min, and discharging organic matters;

step five, sintering:

burying and burning the green body of the organic matters discharged in the fourth step by adopting lead zirconate titanate powder, heating to 1200-1250 ℃ in a box-type furnace at the speed of 3 ℃/min, preserving the heat for 70min, and cooling along with the box-type furnace to obtain ceramics;

step six, silver burning:

grinding the ceramic sintered in the fifth step to a thickness of 2mm, printing silver paste on the upper surface and the lower surface of the ceramic by adopting a screen printing process, and carrying out heat preservation at the temperature of 800 ℃ for 12min to burn the silver;

step seven, polarization:

polarizing the silver-fired ceramic obtained in the step six under different polarization conditions to obtain a piezoelectric ceramic material; the polarization temperature is 100-140 ℃, the polarization time is 20min, and the polarization electric field is 2-3.5 KV/mm; the polarization condition in the step is designed according to the material composition and the size of the ceramic after silver firing, so that the piezoelectric ceramic material after polarization has higher piezoelectricity.

Step eight, testing the piezoelectric performance:

standing the piezoelectric ceramic material subjected to the seven-polarization treatment at room temperature for 24h, testing the piezoelectric performance of the piezoelectric ceramic material, testing the dielectric constant of the piezoelectric ceramic material in a temperature range of-45 ℃ to +125 ℃ by using a digital bridge, and calculating the change rate. And verifying whether the final piezoelectric ceramic material reaches the expected effect by testing the piezoelectric performance so as to verify the preparation result.

The invention is prepared by adding the components into the piezoelectric ceramic body formulaDoping a component having a dielectric constant which decreases with increasing temperature, the component using Ba1-c-dSrcMgdSnaZrbTi1-a-bO3The piezoelectric ceramic material which has good comprehensive performance and has the capacity temperature change controlled between-5% and + 3% in the temperature range of-45 ℃ to +125 ℃ is obtained by doping the components serving as a synthetic body according to a certain mass ratio into the piezoelectric ceramic formula, so that the change amplitude of the dielectric constant of the piezoelectric ceramic material in a certain temperature range is reduced, and the piezoelectric ceramic material still has high sensitivity in harsh high and low temperature environments.

The method for preparing the piezoelectric ceramic material of the present invention will be further described with reference to the following specific examples.

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