An ultrahigh dielectric constant transmitting piezoelectric ceramic material and a method for preparing the same

Abstract

The application discloses an ultrahigh dielectric constant transmitting piezoelectric ceramic material and a preparation method thereof, and belongs to the technical field of piezoelectric ceramic manufacturing. 1‑m‑n Sr m Ca n [(Mn 1 / 3 W 2 / 3 ) x (Co 1 / 3 Nb 2 / 3 ) y (Zr z Ti 1‑z ) 1‑x‑y ]O3+awt%Fe2O3+bwt%CeO2, wherein 0.06<=m<=0.10, 0<=n<=0.05, 0.03<=x<=0.10, 0.05<=y<=0.09, 0.47<=z<=0.53, 0<=a<=0.09, and 0<=b<=0.05. The prepared piezoelectric ceramic material not only has an ultrahigh dielectric constant (epsilon r3 T >=2600), but also has a high coupling coefficient (kp>=0.56), a low dielectric loss (tgdelta<=0.4%), a moderate mechanical quality factor (Q m >=400), and the like. The piezoelectric ceramic material is a transmitting piezoelectric ceramic material with excellent comprehensive performance, can meet diversified performance requirements of piezoelectric ceramic materials of a water sound emission transducer, and has a wide application prospect in the fields of water sound and national defense industry.

Description

Technical Field

[0001] This invention belongs to the field of piezoelectric ceramic manufacturing technology, and relates to an ultra-high dielectric constant emission piezoelectric ceramic material and its preparation method. Background Technology

[0002] Emitter-type piezoelectric ceramic materials are commonly used in the assembly of ultrasonic and underwater acoustic transmitter transducers, and therefore generally require characteristics such as high coupling coefficient, high mechanical quality factor, and low dielectric loss. Currently, P4 and P8 series materials are most commonly used in transmitter transducers; P4 material has a high coupling coefficient and a high mechanical quality factor Q. m ≥600, low dielectric loss, moderate dielectric constant (ε r3 T =1200~1500), commonly used in medium-power transmitter transducers; P8 material has a high coupling coefficient and a mechanical quality factor Q. m ≥800, low dielectric loss, and relatively low dielectric constant (ε) r3 T =800~1200), commonly used in high-power transmitting transducers.

[0003] With the continuous advancement of the national maritime strategy, the demand for maritime power is increasing, placing higher requirements on underwater acoustic transducers. Piezoelectric ceramics, as the core component of underwater acoustic transducers, must meet the diverse needs of these transducers. For example, a certain type of sonar transducer requires piezoelectric ceramics to simultaneously possess ultra-high dielectric constant, high coupling coefficient, low dielectric loss, and a suitable mechanical quality factor. This invention is precisely designed to meet these application requirements. The developed piezoelectric ceramic material not only possesses an ultra-high dielectric constant (ε... r3 T It also features a high coupling coefficient (kp≥0.56), low dielectric loss (tgδ≤0.4%), and a moderate mechanical quality factor (Q). m With characteristics such as ≥400, it is a high-performance emitter piezoelectric ceramic material that can meet the diverse performance requirements of emitter underwater acoustic transducers for piezoelectric ceramic materials, and has broad application prospects in underwater acoustics and defense industries. Summary of the Invention

[0004] The first objective of this invention is to provide a selection of ultra-high dielectric constant emission piezoelectric ceramic materials for the fabrication of underwater acoustic transducers by introducing different component system composition and element doping modification into the binary lead zirconate titanate system, which can meet the diversified development needs of underwater acoustic transducers.

[0005] The second objective of this invention is to provide a method for preparing an ultra-high dielectric constant emission piezoelectric ceramic material.

[0006] The first objective of this invention is achieved through the following technical solution: An ultra-high dielectric constant emission piezoelectric ceramic material, with the following composition: Pb 1-m-n Sr m Ca n [(Mn 1 / 3 W 2 / 3 ) x (Co 1 / 3 Nb 2 / 3 ) y (Zr z Ti 1-z ) 1-x-y O3+awt%Fe2O3+bwt%CeO2, where 0.06≤m≤0.10, 0≤n≤0.05, 0.03≤x≤0.10, 0.05≤y≤0.09, 0.47≤z≤0.53, 0≤a≤0.09, 0≤b≤0.05.

[0007] Preferably, in the composition formula, m = 0.06, 0.08 or 0.10, n = 0, 0.03 or 0.05, x = 0.03, 0.06 or 0.10, y = 0.05, 0.07 or 0.09, z = 0.47, 0.50 or 0.53, a = 0, 0.04 or 0.09, and b = 0, 0.03 or 0.05.

[0008] Preferably, the dielectric constant ε of the piezoelectric ceramic material is... r3 T ≥2600, Mechanical Quality Factor Q m ≥400, planar electromechanical coupling coefficient k p ≥0.56, dielectric loss tgδ≤0.4%.

[0009] The second objective of this invention is achieved through the following technical solution: the ultra-high dielectric constant emission piezoelectric ceramic material of this invention is prepared by the following specific steps:

[0010] (1) Ingredients: Chemically pure Pb3O4, ZrO2, TiO2, SrCO3, CaCO3, MnO2, Nb2O5, Co2O3, WO3, Fe2O3, and CeO2 are selected as raw materials. They are weighed according to the composition ratio, and then placed in a ball mill jar for wet ball milling for 40-50 hours. The slurry is then dried. The ball milling media are deionized water and zirconium oxide balls. The weight ratio of balls:material:water is 2.5-3:1:0.6-0.7.

[0011] (2) Synthesis: After pressing the powder from step (1) into blocks, put it into an Al2O3 crucible and heat it in a high-temperature tunnel kiln at a rate of 2℃ / min to 650℃ and hold it for 1.5 to 3 hours. Then heat it at a rate of 2.5℃ / min to 860 to 920℃ and hold it for 2.5 to 3.5 hours to synthesize the powder.

[0012] (3) Molding and desizing: The material blocks from step (2) are crushed and sieved, then wet-milled for 100-140 hours, dried, and then granulated with 4-8% polyvinyl alcohol binder by weight of the dried powder. The powder is granulated by spray tower to produce ultrafine powder, and then molded into a green body by isostatic pressing at 180MPa for 30s. The green body is then heated to 750-850℃ in a high-temperature tunnel kiln at a rate of 2.5℃ / min and held for 3-5 hours to remove the plastic.

[0013] (4) Sintering: Place the blank from step (3) between the Al2O3 sintering plate and the crucible sprinkled with zirconium powder, and sinter in a high-temperature tunnel kiln at a rate of 2.5℃ / min to 1240~1300 ℃ for 2~3 hours;

[0014] (5) Finished product: The ceramic part from step (4) is ground to the finished size and then ultrasonically cleaned and dried. Electrodes are then printed on its upper and lower surfaces using a screen printing process. After drying, it is placed in a mesh belt furnace and heated to 700-800 ℃ at a rate of 3℃ / min and held for 20-30min to burn silver. Finally, a DC electric field is applied to the silicone oil at 150-160 ℃ in a high-voltage polarization device to obtain the final ultra-high dielectric constant emission piezoelectric ceramic material.

[0015] (6) Measurement: After the sample has been left to stand at room temperature for 5 to 7 days, the resonant frequency fr, anti-resonant frequency fa, and capacitance C of the component are measured on an Agilent 4294A impedance analyzer. T And dielectric loss tgδ, through CB / T 4314-2013, computer electrical coupling coefficient kp, Q m and dielectric constant ε r3 T The samples were tested using a TF Analyzer 2000E under an electric field of 3 kV / mm and the hysteresis loop was measured. The microstructure of the sample cross-section was characterized using a Magellan 400 field emission scanning electron microscope. The dielectric temperature profile of the samples was measured using a Curie temperature measurement system.

[0016] In summary, the advantages of this invention are as follows:

[0017] 1. This invention provides an ultra-high dielectric constant emission piezoelectric ceramic material. By introducing new components and elemental doping modifications to the existing lead zirconate titanate binary piezoelectric ceramic, a dielectric constant ε can be obtained. r3 T≥2600, Mechanical Quality Factor Q m ≥400, planar electromechanical coupling coefficient k p Emitter-type piezoelectric ceramic materials with dielectric properties ≥0.56 and dielectric loss tgδ≤0.4% can meet the diverse performance requirements of emitter-type underwater acoustic transducers for piezoelectric ceramic materials.

[0018] 2. This invention provides a method for preparing ultra-high dielectric constant emission piezoelectric ceramic materials. The raw materials used are all commercially available chemically pure raw materials. Combined with existing conventional powder preparation technology, low-cost, large-scale production can be carried out, giving this type of emission piezoelectric ceramic material broad application prospects in fields such as underwater acoustics and defense industry. Attached Figure Description

[0019] Figure 1 This is a microscopic cross-sectional morphology diagram of the sample from Example 1;

[0020] Figure 2 This is a dielectric temperature curve of the sample prepared in Example 1;

[0021] Figure 3 This is the hysteresis loop diagram of the sample prepared in Example 1. Detailed Implementation

[0022] The present invention will be further described in detail below through specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0023] Example 1

[0024] Preparation of Pb 0.91 Sr 0.06 Ca 0.03 [(Mn 1 / 3 W 2 / 3 ) 0.03 (Co 1 / 3 Nb 2 / 3 ) 0.07 (Zr 0.47 Ti 0.53 ) 0.90 The piezoelectric ceramic of O3 + 0.04wt%Fe2O3 + 0.03wt%CeO2 includes the following steps:

[0025] (1) Ingredients: Chemically pure Pb3O4, ZrO2, TiO2, SrCO3, CaCO3, MnO2, Nb2O5, Co2O3, WO3, Fe2O3, and CeO2 are selected as raw materials. They are weighed according to the composition ratio, and then placed in a ball mill jar for wet ball milling for 40-50 hours. The slurry is then dried. The ball milling media are deionized water and zirconium oxide balls. The weight ratio of balls:material:water is 2.5-3:1:0.6-0.7.

[0026] (2) Synthesis: After pressing the powder from step (1) into blocks, put it into an Al2O3 crucible and heat it in a high-temperature tunnel kiln at a rate of 2℃ / min to 650℃ and hold it for 1.5 to 3 hours. Then heat it at a rate of 2.5℃ / min to 860 to 920℃ and hold it for 2.5 to 3.5 hours to synthesize the powder.

[0027] (3) Molding and desizing: The material blocks from step (2) are crushed and sieved, then wet-milled for 100-140 hours, dried, and then granulated with 4-8% polyvinyl alcohol binder by weight of the dried powder. The powder is granulated by spray tower to produce ultrafine powder, and then molded into a green body by isostatic pressing at 180MPa for 30s. The green body is then heated to 750-850℃ in a high-temperature tunnel kiln at a rate of 2.5℃ / min and held for 3-5 hours to remove the plastic.

[0028] (4) Sintering: Place the blank from step (3) between the Al2O3 sintering plate and the crucible sprinkled with zirconium powder, and sinter in a high-temperature tunnel kiln at a rate of 2.5℃ / min to 1240~1300 ℃ for 2~3 hours;

[0029] (5) Finished product: The ceramic part from step (4) is ground to the finished size and then ultrasonically cleaned and dried. Electrodes are then printed on its upper and lower surfaces using a screen printing process. After drying, it is placed in a mesh belt furnace and heated to 700-800 ℃ at a rate of 3℃ / min and held for 20-30min to burn silver. Finally, a DC electric field is applied to the silicone oil at 150-160 ℃ in a high-voltage polarization device to obtain the final ultra-high dielectric constant emission piezoelectric ceramic material.

[0030] (6) Measurement: After the sample has been left to stand at room temperature for 5 to 7 days, the resonant frequency fr, anti-resonant frequency fa, and capacitance C of the component are measured on an Agilent 4294A impedance analyzer. T And dielectric loss tgδ, through CB / T 4314-2013, computer electrical coupling coefficient kp, Q m and dielectric constant ε r3 TThe samples were tested using a TF Analyzer 2000E under an electric field of 3 kV / mm and the hysteresis loop was measured. The microstructure of the sample cross-section was characterized using a Magellan 400 field emission scanning electron microscope. The dielectric temperature profile of the samples was measured using a Curie temperature measurement system.

[0031] Example 2

[0032] Preparation of Pb 0.92 Sr 0.08 [(Mn 1 / 3 W 2 / 3 ) 0.06 (Co 1 / 3 Nb 2 / 3 ) 0.07 (Zr 0.50 Ti 0.50 ) 0.87 The piezoelectric ceramic is prepared by using chemically pure Pb3O4, ZrO2, TiO2, SrCO3, MnO2, Nb2O5, Co2O3, WO3, and CeO2 as raw materials. The raw materials are accurately weighed according to the stoichiometric ratio of the chemical composition. The remaining preparation methods are the same as steps (1) to (6) in Example 1.

[0033] Example 3

[0034] Preparation of Pb 0.85 Sr 0.10 Ca 0.05 [(Mn 1 / 3 W 2 / 3 ) 0.06 (Co 1 / 3 Nb 2 / 3 ) 0.09 (Zr 0.50 Ti 0.50 ) 0.85 The piezoelectric ceramic of O3+0.09wt%Fe2O3 was prepared by using chemically pure Pb3O4, ZrO2, TiO2, SrCO3, CaCO3, MnO2, Nb2O5, Co2O3, WO3 and Fe2O3 as raw materials, which were accurately weighed according to the stoichiometric ratio of chemical composition. The rest of the preparation method was the same as steps (1) to (6) in Example 1.

[0035] Example 4

[0036] Preparation of Pb 0.89 Sr 0.06 Ca 0.05[(Mn 1 / 3 W 2 / 3 ) 0.03 (Co 1 / 3 Nb 2 / 3 ) 0.09 (Zr 0.53 Ti 0.47 ) 0.88 The piezoelectric ceramic of O3+0.04wt%Fe2O3 was prepared by using chemically pure Pb3O4, ZrO2, TiO2, SrCO3, CaCO3, MnO2, Nb2O5, Co2O3, WO3 and Fe2O3 as raw materials, which were accurately weighed according to the stoichiometric ratio of chemical composition. The rest of the preparation method was the same as steps (1) to (6) in Example 1.

[0037] The performance test results of the above specific embodiments are detailed in Table 1.

[0038] Table 1. Performance Table of Sample Components in the Example

[0039] Example <![CDATA[C T (pF)]]> tgδ(%) <![CDATA[f r (KHz)]]> <![CDATA[f a (KHz)]]> kp <![CDATA[ε r3 T ]]> <![CDATA[Q m ]]> <![CDATA[d 33 ]]> <![CDATA[T c (℃)]]> 1 6676 0.32 106.263 123.030 0.567 2608 402 428 235 2 6950 0.40 106.061 123.954 0.582 2715 417 444 231 3 7016 0.34 105.556 123.939 0.590 2741 451 456 226 4 6950 0.29 106.465 124.080 0.578 2715 484 447 238

[0040] As can be seen from Table 1, the material system involved in this invention can obtain a new type of emission material that is different from traditional emission materials through doping modification. While retaining other typical performance characteristics of traditional emission materials, its dielectric constant is increased by more than 90% compared with traditional P4 series materials, filling the gap in the field of piezoelectric ceramic emission materials in China.

[0041] Depend on Figure 1 It can be seen that the cross-section of the sample in Example 1 has a dense microstructure, with no pores and a grain size of approximately 3~5μm.

[0042] Depend on Figure 2 It can be seen that the Curie temperature of the sample in Example 1 exceeds 235°C, which can meet the environmental temperature requirements for the use of the emitting underwater acoustic transducer.

[0043] Depend on Figure 3 It can be seen that the sample in Example 1 has a saturated hysteresis loop and a saturation polarization intensity exceeding 30 μc / cm. 2 .

[0044] The above description of specific embodiments is only for the purpose of helping to understand and apply the present invention, and is not intended to limit the scope of the present invention. It should be noted that those skilled in the art can make various modifications to the embodiments without departing from the principles of the present invention. Therefore, the present invention is not limited to the embodiments described in this application, and modifications and improvements made to the present invention by those skilled in the art based on the disclosure of the present invention should be within the scope of protection claimed by the present invention.

Claims

1. An ultra-high dielectric constant emission piezoelectric ceramic material, characterized in that: The composition of this piezoelectric ceramic material is Pb. 1-m-n Sr m Ca n [(Mn 1 / 3 W 2 / 3 ) x (Co 1 / 3 Nb 2 / 3 ) y (Zr z Ti 1-z ) 1-x-y O3+awt%Fe2O3+bwt%CeO2, where 0.06≤m≤0.10, 0≤n≤0.05, 0.03≤x≤0.10, 0.05≤y≤0.09, 0.47≤z≤0.53, 0≤a≤0.09, 0≤b≤0.

05.

2. The ultra-high dielectric constant emission piezoelectric ceramic material according to claim 1, characterized in that: In the given formula, m = 0.06, 0.08, or 0.10; n = 0, 0.03, or 0.05; x = 0.03, 0.06, or 0.10; y = 0.05, 0.07, or 0.09; z = 0.47, 0.50, or 0.53; a = 0, 0.04, or 0.09; and b = 0, 0.03, or 0.

05.

3. The ultra-high dielectric constant emission piezoelectric ceramic material according to any one of claims 1 to 2, characterized in that: The dielectric constant ε of the piezoelectric ceramic material r3 T ≥2600, Mechanical Quality Factor Q m ≥400, planar electromechanical coupling coefficient k p ≥0.56, dielectric loss tgδ≤0.4%.

4. The method for preparing an ultra-high dielectric constant emission piezoelectric ceramic material according to claim 3, characterized in that: The steps are as follows: (1) Ingredients: Chemically pure Pb3O4, ZrO2, TiO2, SrCO3, CaCO3, MnO2, Nb2O5, Co2O3, WO3, Fe2O3, and CeO2 are selected as raw materials. They are weighed according to the composition ratio, and then placed in a ball mill jar for wet ball milling for 40-50 hours. The slurry is then dried. The ball milling media are deionized water and zirconium oxide balls. The weight ratio of balls:material:water is 2.5-3:1:0.6-0.

7. (2) Synthesis: After pressing the powder from step (1) into briquettes, place them into an Al2O3 crucible and heat it in a high-temperature tunnel kiln at a rate of 2℃ / min to 650℃ for 1.5 to 3 hours, then heat it at a rate of 2.5℃ / min to 860 to 920℃ for 2.5 to 3.5 hours for synthesis. (3) Molding and desizing: The material blocks from step (2) are crushed and sieved, then wet-milled for 100-140 hours, dried, and then granulated with 4-8% polyvinyl alcohol binder by weight of the dried powder. The powder is granulated by spray tower to produce ultrafine powder, and then molded into a green body by isostatic pressing at 180MPa for 30s. The green body is then heated to 750-850℃ in a high-temperature tunnel kiln at a rate of 2.5℃ / min and held for 3-5 hours to remove the plastic. (4) Sintering: Place the blank from step (3) between the Al2O3 sintering plate and the crucible sprinkled with zirconium powder, and sinter in a high-temperature tunnel kiln at a rate of 2.5℃ / min to 1240~1300℃ for 2~3 hours; (5) Finished product: The ceramic part from step (4) is ground to the finished size and then ultrasonically cleaned and dried. Electrodes are then printed on its upper and lower surfaces using a screen printing process. After drying, it is placed in a mesh belt furnace and heated to 700-800℃ at a rate of 3℃ / min and held for 20-30min to burn silver. Finally, a DC electric field is applied to the silicone oil at 150-160℃ in a high-voltage polarization device to obtain the final ultra-high dielectric constant emission piezoelectric ceramic material.

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