A piezoelectric ceramic material with a wide temperature adaptation range, a sensor and a preparation method and application thereof

Abstract

The application belongs to the technical field of piezoelectric materials, and relates to a piezoelectric ceramic material with a wide temperature adaptation range, a sensor and a preparation method and application thereof. x Ba 1‑x )0.96(Zr 0.42 Ti 0.58 )O3‑(Pb x Ba 1‑x )0.04(Sb 0.5 Nb 0.5 )O3, x=0.88-0.96. The piezoelectric ceramic material formed by lead tetroxide, barium carbonate, niobium pentoxide, antimony trioxide, zirconium dioxide and titanium dioxide in a certain molar number not only has a relatively high piezoelectric coefficient, but also can maintain relatively high stability in a relatively wide temperature range, has high measurement result accuracy, and can be used as a sensor in an ultrasonic gas meter.

Description

Technical Field

[0001] This invention belongs to the field of piezoelectric materials technology, and relates to a piezoelectric ceramic material with a wide temperature adaptability range, a sensor, its preparation method and application. Background Technology

[0002] Piezoelectric sensors are sensors that utilize the piezoelectric effect generated when certain dielectrics are subjected to force. Piezoelectric sensors have advantages such as high sensitivity, high resolution, low noise, high linearity, and high reliability. They can effectively measure various physical quantities, such as pressure, temperature, force, and torque. Therefore, piezoelectric sensors can be used in many different application fields.

[0003] The core component of a piezoelectric sensor is the piezoelectric material, and the performance of the piezoelectric material directly affects the sensor's sensitivity and the accuracy of the detection results. Common piezoelectric materials include piezoelectric ceramics (such as PZT or PZN-PT), piezoelectric crystals, and piezoelectric polymers. Among them, piezoelectric ceramic materials are inorganic piezoelectric materials, which refer to polycrystalline materials obtained by mixing, molding, and high-temperature sintering of raw materials with necessary components. They are formed by the solid-phase reaction between powder particles and the sintering process, resulting in an irregular aggregation of fine grains. They have a high piezoelectric response, strong piezoelectricity, high dielectric constant, and can be processed into arbitrary shapes. However, they have a low mechanical quality factor, high electrical loss, and poor stability. Therefore, they are suitable for applications such as high-power transducers and broadband filters, but are not ideal for high-frequency and high-stability applications. For example, the invention patent document with publication number CN113185286A and titled "Piezoelectric Buzzer and Manufacturing Method Thereof" discloses that the raw materials of the piezoelectric ceramic sheet include: 57-59 parts of lead tetroxide, 18-22 parts of zirconium dioxide, 10-12 parts of titanium dioxide, 7-9 parts of barium carbonate, 1-2 parts of strontium carbonate, 0.3-0.45 parts of niobium pentoxide, and 0.35-0.5 parts of antimony trioxide; and then the piezoelectric ceramic sheet is used to form a piezoelectric buzzer with lead zirconate titanate as the main component. Although existing piezoelectric ceramic materials have good durability and are suitable for ultrasonic applications, for piezoelectric ceramic materials, under the premise of not burning, the larger the piezoelectric ceramic grains, the easier it is to obtain a higher piezoelectric coefficient D33. This results in higher piezoelectric strain characteristics and sensitivity of the piezoelectric ceramic material. However, larger piezoelectric ceramic crystals also bring about unstable temperature characteristics, which greatly limits the application of piezoelectric ceramic materials in sensors, especially for ultrasonic gas meters, water meters, and gas meters. These meters have a wide operating temperature range, but existing piezoelectric ceramic materials have poor stability over a wide temperature range. The capacitance and frequency are prone to large variations with temperature changes, leading to inaccurate detection results. Summary of the Invention

[0004] To address the technical problem that existing piezoelectric ceramic materials have poor stability over a wide temperature range, and that capacitance and frequency are prone to large variations with temperature changes, leading to inaccurate detection results, this invention provides a piezoelectric ceramic material with a wide temperature adaptability range, a sensor, its preparation method, and its applications.

[0005] This invention uses lead tetroxide, barium carbonate, niobium pentoxide, antimony trioxide, zirconium dioxide, and titanium dioxide in a certain molar ratio to form a piezoelectric ceramic material. It not only has a high piezoelectric coefficient, but also maintains high stability over a wide temperature range and provides high measurement accuracy. It can be used as a sensor in ultrasonic gas meters.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A piezoelectric ceramic material with a wide temperature adaptability range, comprising lead tetroxide, barium carbonate, niobium pentoxide, antimony trioxide, zirconium dioxide, and titanium dioxide, with the chemical formula: (Pb x Ba 1-x 0.96(Zr) 0.42 Ti 0.58 )O3-(Pb x Ba 1-x 0.04(Sb) 0.5 Nb 0.5 O3, x = 0.88~0.96, where x is the number of moles.

[0008] Further specified, the frequency change rate of the piezoelectric ceramic material is 0 to 0.101% within the temperature range of -20℃ to 60℃.

[0009] Further specifying, when the piezoelectric coefficient of the piezoelectric ceramic material is 500, the particle size is 2.117 μm.

[0010] The method for preparing the piezoelectric ceramic material with a wide temperature adaptability range includes the following steps:

[0011] S1. Raw material preparation

[0012] Calculate the amounts of lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide in the corresponding raw materials based on the molar number of each element in the chemical formula of the piezoelectric ceramic material.

[0013] S2, ball mill

[0014] The raw materials in step S1 are ball-milled, dried, and pre-fired to obtain ceramic slurry;

[0015] S3, Granulation and Sintering

[0016] The ceramic slurry is granulated to obtain powder with a particle size of 80-120 mesh, and then dry-pressed, debinded and sintered to obtain grains.

[0017] S4, Heat Treatment

[0018] The grains were heat-treated at temperatures of 900℃ to 1120℃ to obtain granular piezoelectric ceramic materials.

[0019] Further specifying, the specific process of the ceramic slurry in step S2 is as follows:

[0020] S2.1 The raw materials in step S1 are mixed, ball-milled for 2 to 4 hours, dried and passed through a 200-mesh sieve to obtain primary abrasive.

[0021] S2.2, the abrasive from step S2.1 is calcined in a sealed environment at 800℃~820℃ for 2h~4h to obtain pre-calcined material;

[0022] S2.3. The pre-burned material from step S2.2 is ball-milled for 2 to 4 hours, dried, and then passed through a 200-mesh sieve to obtain secondary grinding material.

[0023] S2.4 Add 0.8wt% polyvinyl alcohol, 4.5wt% alcohol, 1wt% plasticizer, 2wt% defoamer and 2.5wt% dispersant to the secondary abrasive in step S2.3, and ball mill for 0.5h to 2h to obtain ceramic slurry.

[0024] Further specifying, in step S3, the molding density of the dry pressing is greater than 4.9 g / cm³. 3 The debinding temperature is 720℃~750℃, and the debinding time is 20h~24h; the sintering temperature is 1250℃~1300℃, and the density of the grains after sintering is 7.6g / cm³. 3 .

[0025] A piezoelectric ceramic sheet, the piezoelectric ceramic sheet comprising the piezoelectric ceramic material with a wide temperature adaptability range.

[0026] This can be understood as using the piezoelectric ceramic material with a wide temperature adaptability range of the present invention to make piezoelectric ceramic sheets.

[0027] The piezoelectric ceramic sheet is obtained by sequentially grinding, cutting, coating electrodes, and polarizing piezoelectric ceramic materials with a wide temperature adaptability range.

[0028] A piezoelectric sensor, the piezoelectric sensor comprising the piezoelectric ceramic material with a wide temperature adaptability range or the piezoelectric ceramic sheet.

[0029] This can be understood as using piezoelectric ceramic materials with a wide temperature adaptability range in the fabrication of piezoelectric sensors; or using piezoelectric ceramic sheets as a component of piezoelectric sensors.

[0030] The piezoelectric sensor described herein is used to broaden the temperature adaptability range of ultrasonic gas meters.

[0031] The beneficial effects of this invention are:

[0032] 1. The piezoelectric ceramic material of the present invention includes lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide and niobium pentoxide, and is formulated in a specific molar ratio according to the chemical formula. It not only has a high piezoelectric coefficient, but also maintains high stability over a wide temperature range, ensuring high accuracy of measurement results when the piezoelectric ceramic material is used as a sensor.

[0033] 2. The piezoelectric ceramic material prepared according to the formulation of the present invention exhibits a frequency change rate of 0–0.528% and a capacitance change rate of 0–14.334% within a temperature range of -40℃ to 80℃. Furthermore, within a temperature range of -20℃ to 60℃, the frequency change rate of the piezoelectric ceramic material ranges from 0 to 0.101% and the capacitance change rate ranges from 0 to 10.065%. It is evident that the piezoelectric ceramic material possesses low frequency and capacitance change rates over a wide temperature range, resulting in high sensor stability and high adaptability to environmental temperature changes.

[0034] 3. Through heat treatment, the piezoelectric ceramic material of the present invention not only increases the piezoelectric coefficient D33 to 500, but also produces a piezoelectric ceramic material with a particle size of 2.117 μm, which is smaller than that of existing similar products.

[0035] 4. The piezoelectric ceramic material provided by this invention can not only meet the needs of most sensors, but also its capacitance and frequency change rate with temperature in the temperature range of -40℃ to 80℃ meets or even exceeds the stability of similar international products. It also has high sensitivity and can be used in ultrasonic gas meters. The measurement results are more accurate over a wider temperature range. Attached Figure Description

[0036] Figure 1 This is a diagram of the grain morphology after sintering;

[0037] Figure 2 This is a morphology image after heat treatment;

[0038] Figure 3 The image shows the ceramic grain morphology when the piezoelectric coefficient d33 of a similar Japanese product is 500.

[0039] Figure 4 This is a schematic diagram of the sensitivity amplitude test principle.

[0040] Figure 5 The results show the amplitude comparison between the gas meter sensor prepared according to this invention and similar gas meter sensors in Japan. Detailed Implementation

[0041] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0042] This invention provides a piezoelectric ceramic material with a wide temperature adaptability range, comprising lead tetroxide, barium carbonate, niobium pentoxide, antimony trioxide, zirconium dioxide, and titanium dioxide. The chemical formula of the piezoelectric ceramic material in this invention is: (Pb x Ba 1-x 0.96(Zr) 0.42 Ti 0.58 )O3-(Pb x Ba 1-x 0.04(Sb) 0.5 Nb 0.5 O3, x = 0.88 to 0.96.

[0043] In the above chemical formula, x represents the number of moles. This invention calculates the amount of the corresponding raw material by using the number of moles of each element in the chemical formula.

[0044] The piezoelectric ceramic material provided by this invention has a frequency change rate of less than 1%, a capacitance change rate of less than 2%, and a wide temperature adaptability range.

[0045] When the piezoelectric coefficient of the piezoelectric ceramic material of the present invention is 500, the particle size is 2.117 μm. While maintaining high piezoelectric performance, the piezoelectric ceramic material has a small particle size.

[0046] This invention also provides a method for preparing a piezoelectric ceramic material with a wide temperature adaptability range, comprising the following steps:

[0047] S1. Raw material preparation

[0048] Calculate the amounts of lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide in the corresponding raw materials based on the molar number of each element in the chemical formula of the piezoelectric ceramic material.

[0049] S2, ball mill

[0050] The raw materials in step S1 are ball-milled, dried, and pre-fired to obtain ceramic slurry;

[0051] In step S2 of this invention, the specific process of the ceramic slurry is as follows:

[0052] S2.1 The raw materials in step S1 are mixed, ball-milled for 2 to 4 hours, dried and passed through a 200-mesh sieve to obtain primary abrasive.

[0053] S2.2, the abrasive from step S2.1 is calcined in a sealed environment at 800℃~820℃ for 2h~4h to obtain pre-calcined material;

[0054] S2.3. The pre-burned material from step S2.2 is ball-milled for 2 to 4 hours, dried, and then passed through a 200-mesh sieve to obtain secondary grinding material.

[0055] S2.4 Add 0.8wt% polyvinyl alcohol, 4.5wt% alcohol, 1wt% plasticizer, 2wt% defoamer and 2.5wt% dispersant to the secondary abrasive in step S2.3, and ball mill for 0.5h to 2h to obtain ceramic slurry.

[0056] S3, Granulation and Sintering

[0057] The ceramic slurry is granulated to obtain powder with a particle size of 80-120 mesh, and then dry-pressed, debinded and sintered in sequence to obtain grains;

[0058] In step S3 of this invention, the molding density of the dry-pressed product is greater than 4.9 g / cm³. 3 The debinding temperature is 720℃~750℃, and the debinding time is 20h~24h; the sintering temperature is 1250℃~1300℃, and the density of the grains after sintering is 7.6g / cm³. 3 .

[0059] S4, Heat Treatment

[0060] The grains were heat-treated at temperatures of 900℃ to 1120℃ to obtain granular piezoelectric ceramic materials.

[0061] The present invention also provides a piezoelectric ceramic sheet, which includes the piezoelectric ceramic material with a wide temperature adaptability range described above.

[0062] Specifically, the piezoelectric ceramic sheet is obtained by grinding, cutting, coating with electrodes, and polarizing the piezoelectric ceramic material with a wide temperature adaptability range.

[0063] The present invention also provides a piezoelectric sensor, which includes the piezoelectric ceramic material with a wide temperature adaptability range or the piezoelectric ceramic sheet.

[0064] The application of the piezoelectric sensor provided by this invention in ultrasonic gas meters expands the temperature adaptability range of ultrasonic gas meters and ensures higher accuracy of measurement results.

[0065] The technical solution of the present invention will be further described with reference to specific embodiments.

[0066] Unless otherwise specified, all pharmaceuticals or reagents used in the following examples are commercially available.

[0067] Unless otherwise specified, the operations used in the following embodiments are all conventional operations in the art, such as mixing and drying.

[0068] Example 1

[0069] This embodiment provides a piezoelectric ceramic material with a wide temperature adaptability range, including lead tetroxide, barium carbonate, niobium pentoxide, antimony trioxide, zirconium dioxide, and titanium dioxide.

[0070] The chemical formula of the piezoelectric ceramic material in this embodiment is:

[0071] (Pb x Ba 1-x 0.96(Zr) 0.42 Ti 0.58 )O3-(Pb x Ba 1-x 0.04(Sb) 0.5 Nb 0.5 O3, x = 0.9.

[0072] In this embodiment, x represents the number of moles. The amount of the corresponding raw materials lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide is calculated based on the number of moles of each element in the chemical formula.

[0073] In this embodiment, a method for preparing a piezoelectric ceramic material with a wide temperature adaptability range includes the following steps:

[0074] S1. Raw material preparation

[0075] Calculate the mass of the corresponding raw materials lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide according to the molar number of each element in the chemical formula of the piezoelectric ceramic material, and then weigh each raw material for later use.

[0076] S2, ball mill

[0077] The raw materials in step S1 are ball-milled, dried, and pre-fired to obtain ceramic slurry;

[0078] In step S2, the specific process of preparing the ceramic slurry is as follows:

[0079] S2.1 The raw materials in step S1 are mixed, ball-milled for 4 hours, dried and passed through a 200-mesh sieve to obtain primary abrasive.

[0080] S2.2 and the abrasive from step S2.1 is calcined in a sealed environment at 820℃ for 2 hours to obtain pre-calcined material;

[0081] S2.3. The pre-burned material from step S2.2 is ball-milled for 4 hours, dried, and then passed through a 200-mesh sieve to obtain secondary grinding material;

[0082] S2.4 Add 0.8wt% polyvinyl alcohol, 4.5wt% alcohol, 1wt% plasticizer, 2wt% defoamer and 2.5wt% dispersant to the secondary abrasive in step S2.3, and ball mill for 1 hour to obtain ceramic slurry.

[0083] S3, Granulation and Sintering

[0084] The ceramic slurry is granulated to obtain powder with a particle size of 80 mesh, and then dry-pressed, debinded and sintered to obtain grains.

[0085] In step S3, the molding density of the dry-pressed product is greater than 4.9 g / cm³. 3 The debinding temperature was 750℃, and the debinding time was 24 hours; the sintering temperature was 1290℃, and the sintering time was 2 hours; the density of the grains after sintering was 7.6 g / cm³. 3 .

[0086] S4, Heat Treatment

[0087] The grains were heat-treated at 960℃ for 4 hours to obtain granular piezoelectric ceramic materials.

[0088] Example 2

[0089] This embodiment provides a piezoelectric ceramic material with a wide temperature adaptability range, including lead tetroxide, barium carbonate, niobium pentoxide, antimony trioxide, zirconium dioxide, and titanium dioxide.

[0090] The chemical formula of the piezoelectric ceramic material in this embodiment is:

[0091] (Pb x Ba 1-x 0.96(Zr) 0.42 Ti 0.58 )O3-(Pb x Ba 1-x 0.04(Sb) 0.5 Nb 0.5 O3, x = 0.88.

[0092] In this embodiment, x represents the number of moles. The amount of the corresponding raw materials lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide is calculated based on the number of moles of each element in the chemical formula.

[0093] In this embodiment, a method for preparing a piezoelectric ceramic material with a wide temperature adaptability range includes the following steps:

[0094] S1. Raw material preparation

[0095] Calculate the mass of the corresponding raw materials lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide according to the molar number of each element in the chemical formula of the piezoelectric ceramic material, and then weigh each raw material for later use.

[0096] S2, ball mill

[0097] The raw materials in step S1 are ball-milled, dried, and pre-fired to obtain ceramic slurry;

[0098] In step S2, the specific process of preparing the ceramic slurry is as follows:

[0099] S2.1 The raw materials from step S1 are mixed, ball-milled for 2.5 hours, dried, and then passed through a 200-mesh sieve to obtain primary abrasive.

[0100] S2.2 and the abrasive from step S2.1 is calcined in a sealed environment at 800℃ for 2 hours to obtain pre-calcined material;

[0101] S2.3. The pre-burned material from step S2.2 is ball-milled for 2 hours, dried, and then passed through a 200-mesh sieve to obtain secondary grinding material;

[0102] S2.4 Add 0.8wt% polyvinyl alcohol, 4.5wt% alcohol, 1wt% plasticizer, 2wt% defoamer and 2.5wt% dispersant to the secondary abrasive in step S2.3, and ball mill for 0.5h to obtain ceramic slurry.

[0103] S3, Granulation and Sintering

[0104] The ceramic slurry is granulated to obtain powder with a particle size of 80-120 mesh, and then dry-pressed, debinded and sintered in sequence to obtain grains;

[0105] In step S3, the molding density of the dry-pressed product is greater than 4.9 g / cm³. 3 The debinding temperature was 720℃, and the debinding time was 20 hours; the sintering temperature was 800℃, and the sintering time was 2 hours; the density of the grains after sintering was 7.6 g / cm³. 3 .

[0106] S4, Heat Treatment

[0107] The grains were heat-treated at 900℃ for 2 hours to obtain granular piezoelectric ceramic materials.

[0108] Example 3

[0109] This embodiment provides a piezoelectric ceramic material with a wide temperature adaptability range, including lead tetroxide, barium carbonate, niobium pentoxide, antimony trioxide, zirconium dioxide, and titanium dioxide.

[0110] The chemical formula of the piezoelectric ceramic material in this embodiment is:

[0111] (Pb x Ba 1-x 0.96(Zr) 0.42 Ti 0.58 )O3-(Pb x Ba 1-x 0.04(Sb) 0.5Nb 0.5 O3, x = 0.92.

[0112] In this embodiment, x represents the number of moles. The amount of the corresponding raw materials lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide is calculated based on the number of moles of each element in the chemical formula.

[0113] In this embodiment, a method for preparing a piezoelectric ceramic material with a wide temperature adaptability range includes the following steps:

[0114] S1. Raw material preparation

[0115] Calculate the mass of the corresponding raw materials lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide according to the molar number of each element in the chemical formula of the piezoelectric ceramic material, and then weigh each raw material for later use.

[0116] S2, ball mill

[0117] The raw materials in step S1 are ball-milled, dried, and pre-fired to obtain ceramic slurry;

[0118] In step S2, the specific process of preparing the ceramic slurry is as follows:

[0119] S2.1 The raw materials in step S1 are mixed, ball-milled for 2 hours, dried and passed through a 200-mesh sieve to obtain primary abrasive.

[0120] S2.2 and the abrasive from step S2.1 is calcined in a sealed environment at 810℃ for 4 hours to obtain pre-calcined material;

[0121] S2.3. The pre-burned material from step S2.2 is ball-milled for 3 hours, dried, and then passed through a 200-mesh sieve to obtain secondary grinding material;

[0122] S2.4 Add 0.8wt% polyvinyl alcohol, 4.5wt% alcohol, 1wt% plasticizer, 2wt% defoamer and 2.5wt% dispersant to the secondary abrasive in step S2.3, and ball mill for 1 hour to obtain ceramic slurry.

[0123] S3, Granulation and Sintering

[0124] The ceramic slurry is granulated to obtain powder with a particle size of 120 mesh, and then dry-pressed, debinded and sintered in sequence to obtain grains;

[0125] In step S3, the molding density of the dry-pressed product is greater than 4.9 g / cm³. 3 The debinding temperature was 730℃, and the debinding time was 22 hours; the sintering temperature was 810℃, and the sintering time was 4 hours; the density of the grains after sintering was 7.6 g / cm³. 3 .

[0126] S4, Heat Treatment

[0127] The grains were heat-treated at 1000℃ for 4 hours to obtain granular piezoelectric ceramic materials.

[0128] Example 4

[0129] This embodiment provides a piezoelectric ceramic material with a wide temperature adaptability range, including lead tetroxide, barium carbonate, niobium pentoxide, antimony trioxide, zirconium dioxide, and titanium dioxide.

[0130] The chemical formula of the piezoelectric ceramic material in this embodiment is:

[0131] (Pb x Ba 1-x 0.96(Zr) 0.42 Ti 0.58 )O3-(Pb x Ba 1-x 0.04(Sb) 0.5 Nb 0.5 O3, x = 0.94.

[0132] In this embodiment, x represents the number of moles. The amount of the corresponding raw materials lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide is calculated based on the number of moles of each element in the chemical formula.

[0133] In this embodiment, a method for preparing a piezoelectric ceramic material with a wide temperature adaptability range includes the following steps:

[0134] S1. Raw material preparation

[0135] Calculate the mass of the corresponding raw materials lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide according to the molar number of each element in the chemical formula of the piezoelectric ceramic material, and then weigh each raw material for later use.

[0136] S2, ball mill

[0137] The raw materials in step S1 are ball-milled, dried, and pre-fired to obtain ceramic slurry;

[0138] In step S2, the specific process of preparing the ceramic slurry is as follows:

[0139] S2.1 The raw materials in step S1 are mixed, ball-milled for 4 hours, dried and passed through a 200-mesh sieve to obtain primary abrasive.

[0140] S2.2 and the abrasive from step S2.1 is calcined in a sealed environment at 820℃ for 3 hours to obtain pre-calcined material;

[0141] S2.3. The pre-burned material from step S2.2 is ball-milled for 4 hours, dried, and then passed through a 200-mesh sieve to obtain secondary grinding material;

[0142] S2.4 Add 0.8wt% polyvinyl alcohol, 4.5wt% alcohol, 1wt% plasticizer, 2wt% defoamer and 2.5wt% dispersant to the secondary abrasive from step S2.3, and ball mill for 1.5h to obtain ceramic slurry.

[0143] S3, Granulation and Sintering

[0144] The ceramic slurry is granulated to obtain powder with a particle size of 90 mesh, and then dry-pressed, debinded and sintered in sequence to obtain grains;

[0145] In step S3, the molding density of the dry-pressed product is greater than 4.9 g / cm³. 3 The debinding temperature was 740℃, and the debinding time was 24 hours; the sintering temperature was 820℃, and the sintering time was 3 hours; the density of the grains after sintering was 7.6 g / cm³. 3 .

[0146] S4, Heat Treatment

[0147] The grains were heat-treated at 1050℃ for 3 hours to obtain granular piezoelectric ceramic materials.

[0148] Example 5

[0149] This embodiment provides a piezoelectric ceramic material with a wide temperature adaptability range, including lead tetroxide, barium carbonate, niobium pentoxide, antimony trioxide, zirconium dioxide, and titanium dioxide.

[0150] The chemical formula of the piezoelectric ceramic material in this embodiment is:

[0151] (Pb x Ba 1-x 0.96(Zr) 0.42 Ti 0.58 )O3-(Pb x Ba 1-x 0.04(Sb) 0.5 Nb 0.5 O3, x = 0.96.

[0152] In this embodiment, x represents the number of moles. The amount of the corresponding raw materials lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide is calculated based on the number of moles of each element in the chemical formula.

[0153] In this embodiment, a method for preparing a piezoelectric ceramic material with a wide temperature adaptability range includes the following steps:

[0154] S1. Raw material preparation

[0155] Calculate the mass of the corresponding raw materials lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide according to the molar number of each element in the chemical formula of the piezoelectric ceramic material, and then weigh each raw material for later use.

[0156] S2, ball mill

[0157] The raw materials in step S1 are ball-milled, dried, and pre-fired to obtain ceramic slurry;

[0158] In step S2, the specific process of preparing the ceramic slurry is as follows:

[0159] S2.1 The raw materials in step S1 are mixed, ball-milled for 3 hours, dried and passed through a 200-mesh sieve to obtain primary abrasive.

[0160] S2.2 and the abrasive from step S2.1 is calcined in a sealed environment at 800℃ for 2 hours to obtain pre-calcined material;

[0161] S2.3. The pre-burned material from step S2.2 is ball-milled for 2.5 hours, dried, and then passed through a 200-mesh sieve to obtain secondary grinding material;

[0162] S2.4 Add 0.8wt% polyvinyl alcohol, 4.5wt% alcohol, 1wt% plasticizer, 2wt% defoamer and 2.5wt% dispersant to the secondary abrasive in step S2.3, and ball mill for 2 hours to obtain ceramic slurry.

[0163] S3, Granulation and Sintering

[0164] The ceramic slurry is granulated to obtain powder with a particle size of 110 mesh, and then dry-pressed, debinded and sintered in sequence to obtain grains;

[0165] In step S3, the molding density of the dry-pressed product is greater than 4.9 g / cm³. 3 The debinding temperature was 750℃, and the debinding time was 20 hours; the sintering temperature was 800℃, and the sintering time was 2 hours; the density of the grains after sintering was 7.6 g / cm³. 3 .

[0166] S4, Heat Treatment

[0167] The grains were heat-treated at 1120℃ for 2 hours to obtain granular piezoelectric ceramic materials.

[0168] To verify the performance of the piezoelectric ceramic material in the above embodiments, the following comparative examples were designed for comparison.

[0169] Comparative Example 1

[0170] This comparative example provides a piezoelectric ceramic material with a wide temperature adaptability range, comprising lead tetroxide, barium carbonate, niobium pentoxide, antimony trioxide, zirconium dioxide, and titanium dioxide. The chemical formula of the piezoelectric ceramic material in this comparative example is: (Pb x Ba 1-x 0.96(Zr) 0.42 Ti 0.58 )O3-(Pb x Ba 1-x 0.04(Sb) 0.5 Nb 0.5 O3, x = 0.90.

[0171] In this comparative example, the mass of the corresponding raw material is calculated by the number of moles of each element in the chemical formula, and the corresponding raw material is weighed out for later use.

[0172] In this comparative example, a method for preparing a piezoelectric ceramic material with a wide temperature adaptability range includes the following steps:

[0173] S1. Raw material preparation

[0174] Weigh the corresponding raw materials—lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide—according to the stoichiometric ratio of the chemical formula of the above piezoelectric ceramic material.

[0175] S2, ball mill

[0176] The raw materials in step S1 are ball-milled, dried, and pre-fired to obtain ceramic slurry.

[0177] In step S2, the specific process of preparing the ceramic slurry is as follows:

[0178] S2.1 The raw materials in step S1 are mixed, ball-milled for 4 hours, dried and passed through a 200-mesh sieve to obtain primary abrasive.

[0179] S2.2 The abrasive material from step S2.2 is calcined in a sealed environment at 820℃ for 2 hours to obtain pre-calcined material;

[0180] S2.3. The pre-burned material from step S2.2 is ball-milled for 4 hours, dried, and then passed through a 200-mesh sieve to obtain secondary grinding material;

[0181] S2.4 Add 0.8wt% polyvinyl alcohol, 4.5wt% alcohol, 1wt% plasticizer, 2wt% defoamer and 2.5wt% dispersant to the secondary abrasive in step S2.3, and ball mill for 1 hour to obtain ceramic slurry.

[0182] S3, Granulation and Sintering

[0183] The ceramic slurry is granulated to obtain powder with a particle size of 80-120 mesh. Then, it is dry-pressed, debinded, and sintered to obtain crystals, which are denoted as piezoelectric ceramic materials.

[0184] In step S3, the molding density of the dry-pressed product is greater than 4.9 g / cm³. 3 The debinding temperature was 750℃, and the debinding time was 24 hours; the sintering temperature was 1290℃, and the grain density after sintering was 7.6 g / cm³. 3 .

[0185] Comparative Example 2

[0186] A similar piezoelectric ceramic material, model number Fuji Piezo PZT 5 from Japan, was selected for comparison.

[0187] The performance of the piezoelectric ceramic material in this embodiment was verified through the following tests.

[0188] Experiment 1

[0189] The piezoelectric ceramic materials of Example 1, Comparative Example 1 and Comparative Example 2 were subjected to morphology and piezoelectric coefficient tests, respectively.

[0190] (1) Testing instrument: A scanning electron microscope, model ZEISS ULTRA PLUS, was used to test the morphology images. The operating parameters are as follows:

[0191] Accelerating voltage: 0.02kV~30kV.

[0192] Resolution: 1.0nm at 15kV at WD = 2mm; 1.7nm at 1kV at WD = 2mm; 3.5nm at 0.2kV at WD = 2mm; 4.0nm at 0.1kV at WD = 2mm.

[0193] Electron beam current: 4pA~20pA.

[0194] Multipliers: 12X-1,000,000X (SE mode) and 100X-1,000,000 (BSE mode).

[0195] Working distance: 1mm to 50mm.

[0196] The objective lens is an electromagnetic and electrostatic lens group.

[0197] See SEM morphology results. Figure 1 , Figure 2 and Figure 3 .

[0198] from Figure 1 , Figure 2 and Figure 3 It can be seen that the piezoelectric ceramic material obtained after sintering in Comparative Example 1 has a grain size of 1.964 μm, while the piezoelectric ceramic material obtained after heat treatment in Example 1 has a grain size of 2.117 μm. The grain size of the similar Japanese product Fuji Piezo PZT 5 is approximately 3.426 μm.

[0199] (2) Piezoelectric coefficient test

[0200] The piezoelectric coefficient d33 was determined using a d33 tester.

[0201] D33 tester, model ZJ-3; power supply (220V, 50Hz, 20W); resolution: ×1 range: 1pC / N; ×0.1 range: 0.1pC / N.

[0202] Key technical specifications:

[0203] ★×1st gear: 10 to 2000pC / N,

[0204] ★×0.1 setting: 1 to 200 pC / N

[0205] ★Tolerance: ×1 range: ±2% ±1 digit, when d33 is between 100 and 4000 pC / N;

[0206] ★±5%±1 number, when d33 is between 10 and 200 pC / N;

[0207] ★×0.1 setting: ±2% ±1 digit (when d33 is between 10 and 200 pC / N)

[0208] ±5% ±1 number, when d33 is between 10 and 20 pC / N.

[0209] The three samples were tested using a d33 tester, and the results are as follows: the piezoelectric coefficient d33 of Comparative Example 1 is 450, the piezoelectric coefficient d33 of Example 1 is 500, and the piezoelectric coefficient d33 of the Japanese similar product Fuji Piezo PZT 5 is 500.

[0210] The experimental results above show that, compared to the piezoelectric coefficient d33 of the ceramic material sintered before heat treatment in Comparative Example 1, the piezoelectric coefficient d33 of the ceramic material after heat treatment in Example 1 is increased to 500; this indicates that heat treatment can improve product consistency and increase the piezoelectric coefficient d33 of the material. Compared to similar products from Japan, the piezoelectric ceramic material of Example 1, by heat treatment, achieves a higher piezoelectric coefficient d33 (500) while reducing the grain size of the ceramic particles.

[0211] Experiment 2

[0212] The piezoelectric ceramic material obtained in Example 1 was ground, cut, and coated with electrodes, and then polarized at 1200V / mm to obtain a piezoelectric ceramic sheet, which was then combined with other conventional materials to form a piezoelectric sensor.

[0213] Compared with the piezoelectric sensor in Comparative Example 2, the frequency and capacitance of the two piezoelectric sensors were tested to determine their temperature variation trends.

[0214] During the test, a high and low temperature test chamber and an LCR meter were used to test the frequency and capacitance change trends between -40℃ and 80℃. The test results are shown in Table 1.

[0215] Table 1. Results of frequency and capacitance variations of two piezoelectric sensors with temperature.

[0216]

[0217] As shown in Table 1, within the temperature range of -40℃ to 80℃, the frequency change rate of the piezoelectric ceramic material of the present invention ranges from 0 to 0.528%, and the capacitance change rate ranges from 0 to 14.334%. Furthermore, within the temperature range of -20℃ to 60℃, the frequency change rate of the piezoelectric ceramic material ranges from 0 to 0.101%, and the capacitance change rate ranges from 0 to 10.065%. Compared with similar products from Japan, the piezoelectric ceramic material prepared by the present invention exhibits lower frequency and capacitance change rates over a wider temperature range. This indicates that the piezoelectric ceramic material of Example 1 demonstrates higher stability and greater adaptability to environmental temperature changes over a wider temperature range.

[0218] Experiment 3

[0219] This experiment primarily tests the sensitivity of two types of material sensors and compares the signal intensity amplitude.

[0220] The piezoelectric ceramic material obtained in Example 1 was ground, cut, and coated with electrodes, then polarized at 1200V / mm to obtain a piezoelectric ceramic sheet, which was then used to fabricate a piezoelectric sensor with other conventional materials. This sensor was compared with the piezoelectric sensor in Comparative Example 2.

[0221] The testing process involved using a RIGOL DG822 dual-channel 25MHz function / arbitrary waveform signal generator and a Rigol DS1102E 100MHz digital oscilloscope.

[0222] The performance parameters of the RIGOL DG822 dual-channel 25MHz function / arbitrary waveform signal generator are as follows: maximum output frequency 25MHz, vertical resolution 16bits, 2CH, sampling rate 125Msa / s, standard dual-channel output, built-in 8th order step wave generator, built-in 7digits / s, 240MHz technology, and 4.3-inch TFT color touch screen.

[0223] The performance parameters of the Rigol DS1102E 100MHz digital oscilloscope are as follows: 2 analog channels plus external triggers, 1 million-point deep memory, 1GSa / sec maximum sampling rate, 5.7-inch TFT QVGA (320x240), equipped with a 64K color LCD backlit display, trigger modes: edge, pulse width, slope, video, pattern, continuous time, and alternation.

[0224] Test principle as follows Figure 4 As shown; when driven by 3V, the amplitude test results of the piezoelectric sensor are as follows. Figure 5 As shown in the figure. The left figure shows the amplitude test results of the piezoelectric material in Example 1, and the right figure shows the amplitude test results of Comparative Example 2.

[0225] from Figure 5 As can be seen, the piezoelectric sensor made of piezoelectric ceramic material in Example 1 has an amplitude of 108 mV, compared to 82 mV for a similar Japanese product in Comparative Example 2. The piezoelectric sensor made of piezoelectric ceramic material in Example 1 has higher sensitivity and more accurate detection results.

[0226] The piezoelectric ceramic materials obtained in Examples 2 to 5 were also subjected to morphology and performance tests. They exhibited similar performance to those in Example 1. Compared with similar products on the market, they had smaller particle size at a higher piezoelectric coefficient. Moreover, the piezoelectric ceramic materials showed higher adaptability to changes in ambient temperature over a wider temperature range. The piezoelectric ceramic materials of the present invention can be used as sensors in ultrasonic gas meters, with high sensitivity and more accurate detection results.

[0227] The specific embodiments listed above further illustrate the purpose, technical solution, and beneficial effects of the invention. It should be understood that the above description is only one specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A piezoelectric ceramic material with a wide temperature adaptability range, characterized in that, Piezoelectric ceramic materials include lead tetroxide, barium carbonate, niobium pentoxide, antimony trioxide, zirconium dioxide, and titanium dioxide. The chemical formulas of piezoelectric ceramic materials are: 0.96(Pb x Ba 1-x )(Zr 0.42 Ti 0.58 )O3-0.04(Pb x Ba 1-x )(Sb 0.5 Nb 0.5 )O3,x=0.88~0.96。 2. The piezoelectric ceramic material with a wide temperature adaptability range according to claim 1, characterized in that, Within a temperature range of -20℃ to 60℃, the frequency change rate of the piezoelectric ceramic material is 0 to 0.101%.

3. The piezoelectric ceramic material with a wide temperature adaptability range according to claim 1, characterized in that, When the piezoelectric coefficient of the piezoelectric ceramic material is 500, the particle size is 2.117 μm.

4. The method for preparing a piezoelectric ceramic material with a wide temperature adaptability range as described in claim 2, characterized in that, Includes the following steps: S1. Raw material preparation Calculate the amounts of lead tetroxide, barium carbonate, zirconium dioxide, titanium dioxide, antimony trioxide, and niobium pentoxide in the corresponding raw materials based on the molar number of each element in the chemical formula of the piezoelectric ceramic material. S2, ball mill The raw materials in step S1 are ball-milled, dried, and pre-fired to obtain ceramic slurry; S3, Granulation and Sintering The ceramic slurry is granulated to obtain powder with a particle size of 80-120 mesh, and then dry-pressed, debinded and sintered in sequence to obtain grains; S4, Heat Treatment The grains were heat-treated at temperatures of 900℃ to 1120℃ to obtain granular piezoelectric ceramic materials.

5. The preparation method according to claim 4, characterized in that, In step S2, the specific process of the ceramic slurry is as follows: S2.1 The raw materials in step S1 are mixed, ball-milled for 2-4 hours, dried and passed through a 200-mesh sieve to obtain primary abrasive. S2.2 and the abrasive from step S2.1 is calcined in a sealed environment at a temperature of 800℃~820℃ for 2h~4h to obtain pre-calcined material; S2.

3. The pre-burned material from step S2.2 is ball-milled for 2-4 hours, dried, and then passed through a 200-mesh sieve to obtain secondary grinding material. S2.4 Add 0.8wt% polyvinyl alcohol, 4.5wt% alcohol, 1wt% plasticizer, 2wt% defoamer and 2.5wt% dispersant to the secondary abrasive in step S2.3, and ball mill for 0.5h~2h to obtain ceramic slurry.

6. The preparation method according to claim 4, characterized in that, In step S3, the molding density of the dry-pressed product is greater than 4.9 g / cm³. 3 The debinding temperature is 720℃~750℃, and the debinding time is 20h~24h; the sintering temperature is 1250℃~1300℃, and the grain density after sintering is 7.6g / cm³. 3 .

7. A piezoelectric ceramic sheet, characterized in that, The piezoelectric ceramic sheet includes the piezoelectric ceramic material with a wide temperature adaptability range as described in claim 1.

8. The piezoelectric ceramic sheet according to claim 7, characterized in that, The piezoelectric ceramic sheet is obtained by sequentially grinding, cutting, coating electrodes, and polarizing piezoelectric ceramic materials with a wide temperature adaptability range.

9. A piezoelectric sensor, characterized in that, The piezoelectric sensor comprises the piezoelectric ceramic material with a wide temperature adaptability range as described in claim 1 or the piezoelectric ceramic sheet as described in claim 8.

10. The application of the piezoelectric sensor as described in claim 9 in expanding the temperature adaptability range of ultrasonic gas meters.

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