CN105218092B - It is a kind of to be provided simultaneously with big displacement and low delayed lead zirconate titanate based piezoelectric ceramic materials and preparation method thereof - Google Patents

Abstract

The invention relates to a lead zirconate titanate-based piezoelectric ceramic material with large displacement and low hysteresis and a preparation method thereof. The general formula of the ceramic material is: Pb _1‑x (Sr _y Ca _1‑y ) _x (Zr _z Ti _1‑z )O ₃ +aCa(Fe _w Ga _1‑w )O _5/2 +bMnO ₂ , where: x, y, z and w are molar ratios, 0.05≤x≤0.20, 0≤ y≤1, 0.50≤z≤0.55, 0≤w≤1; a is the molar ratio, based on the total mole of Pb _1‑x (Sr _y Ca _1‑y ) _x (Zr _z Ti _1‑z )O ₃ ceramic powder The number is 1, 0.005≤a≤0.01; b is the weight ratio, based on the total weight of Pb _1‑x (Sr _y Ca _1‑y ) _x (Zr _z Ti _1‑z )O ₃ ceramic powder is 1, 0 ≤b≤0.01. This type of ceramic has the characteristics of large displacement and low hysteresis at the same time, and the ceramic electric field-strain curve can meet the application requirements of high-precision piezoelectric actuators, and has great application prospects.

Description

A lead zirconate titanate-based piezoelectric ceramic material with both large displacement and low hysteresis and its preparation method

technical field

The invention relates to a piezoelectric ceramic with large piezoelectric displacement and low displacement hysteresis and a preparation method thereof, belonging to the technical field of functional ceramic materials.

Background technique

Ferroelectric materials can realize the mutual conversion of mechanical energy and electrical energy, so they are widely used in the fields of transducers, sensors, and drives. ^[1] Among them, piezoelectric drives use piezoelectric materials to produce micro-displacement action execution device. Piezoelectric actuators have the advantages of high displacement control precision, fast response speed, and large thrust, and are widely used in many fields such as civil and national defense. ^[2]

With the advancement of technology, the application range of piezoelectric micro-displacement drivers has gradually expanded. For example, in nano-engineering, high-precision processing and positioning systems, piezoelectric micro-displacement drivers also have very important applications. These systems have very high requirements for piezoelectric micro-displacement drivers, such as large piezoelectric displacement, low voltage-displacement hysteresis, and high linearity. Piezoelectric material will produce displacement under the action of electric field, but its displacement is inconsistent when the electric field rises and falls, which is the voltage-displacement hysteresis. ^[3-4] The existence of displacement lag will seriously reduce the positioning accuracy of the system. Therefore, in such high-precision systems, it is generally required that the displacement lag is less than 5%.

The displacement hysteresis of piezoelectric materials is the most important factor affecting the accuracy of piezoelectric actuators. Therefore, researchers from all over the world are doing a lot of research work to reduce the hysteresis. At present, the commonly used method is to establish a mathematical model of piezoelectric actuator lag, such as the Presiach model, etc. ^[5] These methods need to increase the feedforward control system, which increases the complexity and difficulty of the system. Therefore, the effective method is still to directly reduce the displacement hysteresis of the piezoelectric material itself. Currently commonly used PZT piezoelectric ceramics, when softly doped, have a high piezoelectric constant (d ₃₃ >350pC/N), but the displacement hysteresis is also large (>15%); and when hard doped , its displacement hysteresis will be significantly reduced (<10%), but its piezoelectric constant will also be greatly reduced (<220pC/N). ^[6-7] For example, PZT-8, a common low-hysteresis piezoelectric material abroad, has a piezoelectric constant d ₃₃ of 220PC/N and a displacement hysteresis of 5-10%.

At the same time, for hard-doped piezoelectric ceramics, due to the high concentration of oxygen vacancies in the material, the oxygen vacancies pin the domain walls during polarization at room temperature, resulting in the inability of the electric domains to turn. change. However, at high temperatures, the leakage conductance of such ceramics will increase sharply, resulting in very easy breakdown of ceramics under high temperature and high voltage. Therefore, effective polarization for such materials is also very difficult.

To sum up, among the current commercial piezoelectric ceramic materials, no piezoelectric material with both large displacement and low hysteresis has been found. At the same time, there are many problems in the preparation process of the commonly used low hysteresis piezoelectric ceramics. Therefore, finding piezoelectric ceramic materials with large displacement and low hysteresis at the same time, and improving its polarization and other preparation processes are still the direction of efforts of researchers from all over the world.

references:

[1] B. Jaffe, W. R. Cook, and H. Jaffe, Piezoelectric Ceramics, Academic Press, New York, 1971;

[2] Chen Daren, Overview of Piezoelectric Micro-displacement Actuators, Electronic Components and Materials, 1994, 13[1]: 2-7;

[3] Zhang Tao, Sun Lining, Cai Hegao, Research on the Basic Properties of Piezoelectric Ceramics, Optical Precision Engineering, 1998, 6[5]: 26-32;

[4] Jonq-Jer Tzen, Shyr-Long Jeng, Wei-Hua Chieng, Modeling of piezoelectric actuator for compensation and controller design, Precision Engineering, 2003, 27:70–86;

[5] G.Robert, D.Damjanovic, and N.Setter, Preisach distribution function approach to piezoelectric nonlinearity and hysteresis, J.Appl.Phys., 2001, 90[5]: 2459-2464;

[6] Takaaki TSURUMI, Tsutomu SASAKI, Hirofumi KAKEMOTO, Takakiyo HARIGAI and Satoshi WADA, Domain Contribution to Direct and Converse Piezoelectric Effects of PZT Ceramics, J.J.Appl.Phys., 2004,43[11]:7618–7622;

[7] Shujun Zhang, Jong Bong Lim, Hyeong Jae Lee, and Thomas R. Shrout, Characterization of Hard Piezoelectric Lead-Free Ceramics, IEEE Trans.UFFC, 2009, 56[8]: 1523-1527.

Contents of the invention

In order to solve the problems that the existing piezoelectric ceramics cannot have the characteristics of large displacement and low hysteresis at the same time, and it is difficult to polarize, etc., the present invention provides a lead zirconate titanate-based piezoelectric ceramic material formula, which has large piezoelectric displacement, Low voltage-displacement hysteresis and good linearity; at the same time, the invention solves the problem of difficult polarization of existing rigid piezoelectric ceramics through high temperature quenching and room temperature polarization processes.

Here, on the one hand, the present invention provides a lead zirconate titanate-based piezoelectric ceramic material with both large displacement and low hysteresis. The general composition formula of the ceramic material is: Pb _1-x (Sry Ca _{1- y} ) _x (Zr _z Ti _1-z )O ₃ +aCa(Fe _w Ga _1-w )O _5/2 +bMnO ₂ (abbreviated as PSZT-CFGO), where: x, y, z and w are molar ratios , 0.05≤x≤0.20, 0≤y≤1, 0.50≤z≤0.55, 0≤w≤1; a is the molar ratio, based on the total moles of PSZT ceramic powder as 1, 0.005≤a≤0.01; b is Weight ratio, based on the total weight of PSZT ceramic powder as 1, 0≤b≤0.01.

The piezoelectric constant d ₃₃ of the ceramic material is 292-342pC/N, and the displacement hysteresis is 2%-5%. Therefore, this type of ceramic has the characteristics of large displacement and low hysteresis at the same time, and the electric field-strain curve of the ceramic can meet the application requirements of high-precision piezoelectric actuators, and has great application prospects.

_On the other hand, the present invention also provides a method for preparing a lead zirconate _{titanate -} based piezoelectric ceramic material with both large displacement and low hysteresis. CaCO ₃ , ZrO ₂ , TiO ₂ , Fe ₂ O ₃ , Ga ₂ O ₃ and MnO ₂ according to Pb _1-x (Sr _y Ca _1-y ) _x (Zr _z Ti _1-z )O ₃ +aCa(Fe _w Ga _1-w )O _5/2 +bMnO ₂ stoichiometric ratio weighing, put the raw material powder into a ball mill jar, add deionized water, mix for 4-6 hours, pour out and dry; step 2) Mix the The uniform powder is sieved, briquetted, synthesized at 800-950°C for 2-4 hours, crushed the synthesized powder, put it into a ball mill jar, add deionized water, ball mill for 6-8 hours, pour out Drying; step 3) adding binder to the powder obtained in step 2), granulating, pressing and molding, and keeping the pressed green body at a temperature of 500-650°C for 2-6 hours; step 4) making the green body Sinter at 1260-1300°C for 2-4 hours, grind both sides, and cover the surface with electrodes; Step 5) Polarize the ceramics after covering the electrodes to obtain a lead zirconate titanate-based piezoelectric ceramic material with both large displacement and low hysteresis .

In the present invention, the powder is synthesized by a solid-state method, then sintered and compacted in a high-temperature furnace, and the ceramic-coated electrode is quenched at a high temperature, and then high-voltage polarization is applied at room temperature. The ceramic material provided by the invention has large piezoelectric displacement, low displacement hysteresis and high linearity, and is very suitable for making high-precision piezoelectric micro-displacement drivers, and is used in fields such as precision control and high-precision positioning. Moreover, the preparation process of the material of the present invention is simple, it can be polarized at room temperature without breakdown, and is very suitable for industrial production.

In said step 3), the binder added is PVA or PVB.

Also, in the step 3), the pressure of the press molding is 150-250MP.

In the present invention, the electrode coated on the surface in the step 4) is a silver electrode or a platinum electrode.

In the present invention, the polarization process in step 5) includes: heating the electrode-coated ceramics to 500° C., quenching in water, and then applying a voltage of 2-4 kV/mm at room temperature for polarization.

Description of drawings

Fig. 1 is the XRD spectrogram of the ceramic material that embodiment 1 makes;

Fig. 2 is the electric hysteresis loop before the polarization of the ceramics that embodiment 1 makes;

Fig. 3 is the electric hysteresis loop after the high temperature quenching of ceramics that embodiment 1 makes;

Fig. 4 is the strain curve of the ceramic prepared in Example 1 under a unidirectional electric field of 1 kV/cm.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and the following embodiments. It should be understood that the following embodiments are only used to illustrate the present invention, not to limit the present invention.

The lead zirconate titanate-based piezoelectric ceramic material provided by the invention simultaneously has large piezoelectric displacement, low piezoelectric-displacement hysteresis and high linearity.

The general composition formula of the lead zirconate titanate-based piezoelectric ceramic material with both large displacement and low hysteresis in the present invention is: Pb _1-x (Sry Ca _{1-y ) x} (Zr _z Ti _1-z )O ₃ +aCa(Fe _w Ga _1-w )O _5/2 +bMnO ₂ (abbreviated as PSZT-CFGO), where: x, y, z and w are all molar ratios, and satisfy 0.05≤x≤0.20, 0≤y ≤1, 0.50≤z≤0.55, 0≤w≤1; a is the molar ratio, based on the total molar number of PSZT ceramic powder as 1, and satisfies 0.005≤a≤0.01; b is the weight ratio, based on PSZT ceramic powder The total weight is counted as 1 and satisfies 0≤b≤0.01.

The low-hysteresis large-displacement piezoelectric ceramics obtained by the invention can be used to manufacture high-precision piezoelectric drivers, and has broad application prospects in the fields of precision control and processing.

The preparation method of the present invention comprises:

Step 1) According to the general formula of Pb _1-x (Sr _y Ca _1-y ) _x (Zr _z Ti _1-z )O ₃ +aCa(Fe _w Ga _1-w )O _5/2 +bMnO ₂ , accurately weigh the chemical Metering ratio of Pb ₃ O ₄ , SrCO ₃ , CaCO ₃ , ZrO ₂ , TiO ₂ , Fe ₂ O ₃ , Ga ₂ O ₃ and MnO ₂ . Put all raw material powders into a ball mill jar, add deionized water, mix for 4 to 6 hours, pour out and dry;

Step 2) After sieving and briquetting the uniformly mixed powder, place it in a high-temperature furnace, and synthesize it at 800-950°C for 2-4 hours to obtain the required phase;

Step 3) crush the synthesized powder, put it into a ball mill jar, add deionized water, ball mill it for 6-8 hours, pour it out and dry it;

Step 4) Adding PVA to the ball-milled powder as a binder, granulating, pressing and molding under a pressure of 150-250 MPa, and keeping the pressed green body at a temperature of 500-650°C for 2-6 hours to discharge the green body organic ingredients in

Step 5) Put the biscuit into a high-temperature sintering furnace, sinter at 1260-1300°C for 2-4 hours, and after grinding on both sides to the required size, the surface is covered with electrodes;

Step 6) Heat the ceramic covered with electrodes to 500°C, quench in water, and then apply a voltage of 2 to 4kV/mm to polarize at room temperature to obtain a lead zirconate titanate base voltage with both large displacement and low hysteresis Electroceramic materials.

The beneficial effects of the present invention are: compared with the prior art, the piezoelectric constant d33 of the lead zirconate titanate-based piezoelectric ceramic material provided by the present invention can reach _342pC /N; the voltage displacement hysteresis is as low as 2.5%, and the nonlinearity is less than 5% %, to meet the needs of high-precision control and positioning, and has broad application prospects. Moreover, the preparation process of the material of the present invention is simple, it can be polarized at room temperature without breakdown, and is very suitable for industrial production.

Examples are given below to describe the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention, and should not be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art according to the above contents of the present invention all belong to the present invention scope of protection. The specific process parameters and the like in the following examples are only examples of suitable ranges, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific values exemplified below.

Example 1: Pb _0.90 Sr _0.05 Ca _0.05 Zr _0.53 Ti _0.47 O ₃ -0.01CaFeO _5/2

Including the following steps:

1) According to the general formula of Pb _0.90 Sr _0.05 Ca _0.05 Zr _0.53 Ti _0.47 O ₃ -0.01CaFeO _5/2 , accurately weigh the stoichiometric ratio of Pb ₃ O ₄ , SrCO ₃ , CaCO ₃ , ZrO ₂ , TiO ₂ , Fe ₂ O ₃ . Put all raw material powders into a ball mill jar, add deionized water, mix for 4-6 hours, pour out and dry;

2) After sieving and briquetting the uniformly mixed powder, place it in a high-temperature furnace and synthesize it at 810°C for 2 hours to obtain the required phase;

3) Break the synthesized powder into a ball mill tank, add deionized water, and pour it out for drying after 6 hours of ball milling;

4) adding PVA to the ball-milled powder as a binder, granulating, pressing and molding under a pressure of 200 MPa, and keeping the pressed green body at a temperature of 550° C. for 4 hours to discharge the organic components in the green body;

5) Put the biscuit into a high-temperature sintering furnace, sinter at 1280°C for 2-4 hours, and after grinding on both sides to the required size, the surface is covered with electrodes;

6) After heating the electrode-coated ceramics to 500°C, quenching in water, and then applying a voltage polarization of 4kV/mm at room temperature, piezoelectric ceramics with large displacement and low hysteresis can be obtained.

The phase analysis of the prepared ceramic material was carried out with a D/max2550V diffractometer, and the obtained XRD spectrum is shown in FIG. 1 . It can be seen from Figure 1 that the ceramic is a tetragonal perovskite structure.

Figure 2 is the hysteresis loop of the ceramic material prepared in this example before polarization. It can be seen from Figure 2 that because there are more oxygen vacancies in the ceramic, the domain wall is strongly pinned, so the hysteresis loop of the ceramic is bundled. waist shape.

Fig. 3 and Fig. 2 are the electric hysteresis loops of the ceramic materials prepared in this embodiment after quenching. It can be seen from Fig. 3 that the ceramic domain walls after high-temperature quenching are no longer pinned, so they present normal electric hysteresis loops.

Fig. 4 is the strain curve of the ceramic prepared in this embodiment under a unidirectional electric field of 1 kV/cm. It can be seen from the figure that the ceramic has extremely low displacement hysteresis and good linearity.

The electrical properties of the above prepared piezoelectric ceramics are:

Example 2: Pb _0.90 Sr _0.10 Zr _0.53 Ti _0.47 O ₃ -0.008CaFe _0.95 Ga _0.05 O _5/2 +0.005MnO ₂

Including the following steps:

_{1 )} Accurately _{weigh stoichiometric} ratios of _{Pb 3 O 4} , _{SrCO 3} , _{ZrO 2} , _{TiO 2} , CaCO ₃ , Fe ₂ O ₃ , Ga ₂ O ₃ , MnO ₂ . Put all raw material powders into a ball mill jar, add deionized water, mix for 4-6 hours, pour out and dry;

2) After sieving and briquetting the uniformly mixed powder, place it in a high-temperature furnace and synthesize it at 820°C for 2 hours to obtain the required phase;

3) Break the synthesized powder into a ball mill tank, add deionized water, and pour it out for drying after 6 hours of ball milling;

4) adding PVA to the ball-milled powder as a binder, granulating, pressing and molding under a pressure of 200 MPa, and keeping the pressed green body at a temperature of 550° C. for 4 hours to discharge the organic components in the green body;

5) Put the biscuit into a high-temperature sintering furnace, sinter at 1300°C for 2 hours, and after grinding on both sides to the required size, the surface is covered with electrodes;

6) After heating the electrode-coated ceramics to 500°C, quenching in water, and then applying a voltage polarization of 4kV/mm at room temperature, piezoelectric ceramics with large displacement and low hysteresis can be obtained.

The electrical properties of the above prepared piezoelectric ceramics are:

Example 3: Pb _0.85 (Sr _0.3 Ca _0.7 ) _0.15 Zr _0.51 Ti _0.49 O ₃ -0.01Ca(Fe _0.75 Ga _0.15 )O _5/2 +0.006MnO ₂

Including the following steps:

1) According to the general formula of Pb _0.85 (Sr _0.3 Ca _0.7 ) _0.15 Zr _0.51 Ti _0.49 O ₃ -0.01Ca (Fe _0.75 Ga _0.15 )O _5/2 +0.006MnO ₂ , accurately weigh the stoichiometric ratio of Pb ₃ O ₄ , SrCO _3. CaCO ₃ , ZrO ₂ , TiO ₂ , Fe ₂ O ₃ , Ga ₂ O ₃ , MnO ₂ . Put all raw material powders into a ball mill jar, add deionized water, mix for 4-6 hours, pour out and dry;

2) After sieving and briquetting the uniformly mixed powder, place it in a high-temperature furnace and synthesize it at 850°C for 2 hours to obtain the required phase;

3) Break the synthesized powder into a ball mill tank, add deionized water, and pour it out for drying after 6 hours of ball milling;

4) adding PVA to the ball-milled powder as a binder, granulating, pressing and molding under a pressure of 200 MPa, and keeping the pressed green body at a temperature of 550° C. for 4 hours to discharge the organic components in the green body;

5) Put the biscuit into a high-temperature sintering furnace, sinter at 1300°C for 2 hours, and after grinding on both sides to the required size, the surface is covered with electrodes;

6) After heating the electrode-coated ceramics to 500°C, quenching in water, and then applying a voltage polarization of 4kV/mm at room temperature, piezoelectric ceramics with large displacement and low hysteresis can be obtained.

The electrical properties of the above prepared piezoelectric ceramics are:

Example 4: Pb _0.95 (Sr _0.9 Ca _0.1 ) _0.05 Zr _0.55 Ti _0.45 O ₃ -0.006Ca(Fe _0.5 Ga _0.5 )O _5/2 +0.002MnO ₂

Including the following steps:

1) According to the general formula of Pb _0.95 (Sr _0.9 Ca _0.1 ) _0.05 Zr _0.55 Ti _0.45 O ₃ -0.006Ca(Fe _0.5 Ga _0.5 )O _5/2 +0.002MnO ₂ , accurately weigh the stoichiometric ratio of Pb ₃ O ₄ , SrCO _3. CaCO ₃ , ZrO ₂ , TiO ₂ , Fe ₂ O ₃ , Ga ₂ O ₃ , MnO ₂ . Put all raw material powders into a ball mill jar, add deionized water, mix for 4-6 hours, pour out and dry;

2) After sieving and briquetting the uniformly mixed powder, place it in a high-temperature furnace and synthesize it at 810°C for 4 hours to obtain the required phase;

3) Break the synthesized powder into a ball mill tank, add deionized water, and pour it out for drying after 6 hours of ball milling;

4) Adding PVA to the ball-milled powder as a binder, granulating, pressing and molding under a pressure of 250 MPa, and keeping the pressed green body at a temperature of 600° C. for 4 hours to discharge the organic components in the green body;

5) Put the biscuit into a high-temperature sintering furnace, sinter at 1290°C for 2 hours, and after grinding on both sides to the required size, the surface is covered with electrodes;

6) After heating the electrode-coated ceramics to 500°C, quenching in water, and then applying a voltage polarization of 4kV/mm at room temperature, piezoelectric ceramics with large displacement and low hysteresis can be obtained.

The electrical properties of the above prepared piezoelectric ceramics are:

Industrial applicability: The piezoelectric constant d ₃₃ of the lead zirconate titanate-based piezoelectric ceramics prepared by the present invention is between 300-342pC/N; the displacement hysteresis is between 2%-5%; therefore, this type of ceramics has both large displacement and The characteristics of low hysteresis and the ceramic electric field-strain curve can meet the application requirements of high-precision piezoelectric actuators and have great application prospects.

Claims (6)

1. A lead zirconate titanate-based piezoelectric ceramic material with large displacement and low hysteresis, characterized in that the general formula of the ceramic material is: Pb _1-x (Sry Ca _{1-y ) x} ( Zr _z Ti _1-z )O ₃ +aCa(Fe _w Ga _1-w )O _5/2 +bMnO ₂ , where: x, y, z and w are molar ratios, 0.05≤x≤0.20, 0<y ≤1, 0.50≤z≤0.55, 0<w≤1; a is the molar ratio, based on the total moles of Pb _1-x (Sr _y Ca _1-y ) _x (Zr _z Ti _1-z )O ₃ ceramic powder is 1, 0.005≤a≤0.01; b is the weight ratio, based on the total weight of Pb _1-x (Sry Ca _{1-y ) x} (Zr _z Ti _1-z )O ₃ ceramic powder as 1, 0≤ b≤0.01; The piezoelectric constant d ₃₃ of the ceramic material is 292-342pC/N, and the displacement hysteresis is 2%-5%. 2. a preparation method of the lead zirconate titanate-based piezoelectric ceramic material with large displacement and low hysteresis simultaneously as claimed in claim 1, characterized in that, the preparation method comprises: Step 1) Weigh the raw materials Pb ₃ O ₄ , SrCO ₃ , CaCO ₃ , ZrO ₂ , TiO ₂ , Fe ₂ O ₃ , Ga ₂ O ₃ , and MnO ₂ according to the stoichiometric ratio of the general composition formula, and put the raw material powder into Put it into a ball mill jar, add deionized water, mix for 4 to 6 hours, pour it out and dry it; Step 2) Sieve the evenly mixed powder, briquette, synthesize at 800-950°C for 2-4 hours, crush the synthesized powder, put it into a ball mill tank, add deionized water, and ball mill for 6-4 hours 8 hours, pour out and dry; Step 3) adding binder to the powder obtained in step 2), granulating, pressing and molding, and keeping the pressed green body at a temperature of 500-650°C for 2-6 hours; Step 4) Sinter the biscuit at 1260-1300°C for 2-4 hours, grind both sides flat, and cover the surface with electrodes; Step 5) Polarize the ceramics covered with electrodes to obtain a lead zirconate titanate-based piezoelectric ceramic material with both large displacement and low hysteresis. 3. The preparation method according to claim 2, characterized in that the binder added in step 3) is PVA or PVB. 4 . The preparation method according to claim 2 , characterized in that, the compression molding pressure in step 3) is 150-250 MPa. 5 . The preparation method according to claim 2 , wherein the surface-coated electrode in step 4) is a silver electrode or a platinum electrode. 6. The preparation method according to any one of claims 2 to 5, characterized in that the polarization process in step 5) includes: heating the ceramics covered with electrodes to 500°C, quenching them in water, and then heating them at room temperature Apply a voltage polarization of 2-4kV/mm.