High-temperature magnesium bismuth titanate-lead zirconate titanate piezoelectric ceramic material and preparation method thereof

Abstract

The invention belongs to the technical field of piezoelectric ceramics, and particularly relates to a high-temperature magnesium bismuth titanate-lead zirconate titanate piezoelectric ceramic material and a preparation method thereof. Comprising the following chemical general formula: 0.65 Bi (Mg < 0.51 > Ti < 0.49 >) O < 3 >-0.35 Pb (Zr < x > Ti < 1-x >) O < 3-y > wt% La2O3, wherein x is equal to 0.01 to 0.7, and y is equal to 0.01 to 2. The piezoelectric ceramic material is prepared from the following raw materials: Pb3O4, TiO2, ZrO2, Nb2O5, Bi2O3, MgO and La2O3. The novel piezoelectric ceramic system has higher Curie temperature of 460-520 DEG C, and can work in a high-temperature environment of 260-400 DEG C. The novel piezoelectric ceramic system is suitable for being applied to a high-temperature sensor piezoelectric device.

Description

Technical Field

[0001] This invention belongs to the field of piezoelectric ceramic technology, and specifically relates to a high-temperature bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material and its preparation method. Background Technology

[0002] With the development of science and technology, the demand for detection and sensing in high-temperature scenarios has surged, leading to a sharp increase in the demand for piezoelectric materials used in high-temperature environments. However, traditional piezoelectric materials cannot operate in high-temperature environments. Specifically, conventional P-4 and P-5 series piezoelectric ceramics can only operate stably at 100℃ to 150℃ and lose their piezoelectric properties at around 270℃. Therefore, it is necessary to develop piezoelectric ceramics that can operate at 260℃ to 400℃ to meet market demand.

[0003] In view of the above requirements, a more in-depth study should be conducted on the composition, structure and properties of bismuth magnesium titanate-lead zirconate titanate materials, and the materials should be designed and developed through methods such as component doping, phase structure and preparation process. Summary of the Invention

[0004] The purpose of this invention is to provide a high-temperature bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material and its preparation method. This invention aims to meet the demand for high-temperature piezoelectric materials in the field of high-temperature sensors, and has a high Curie temperature of 460℃~520℃.

[0005] To address the aforementioned technical problems, this invention provides a high-temperature bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material, the chemical formula of which is 0.65Bi(Mg) 0.51 Ti 0.49 O3-0.35Pb(Zr) x Ti 1-x )O3-ywt%La2O3; where x = 0.01~0.7, y = 0.01~2.

[0006] Preferably, x = 0.25 to 0.55 and y = 0.25 to 0.85.

[0007] Preferably, the raw materials for preparing the piezoelectric ceramic material include Pb3O4, TiO2, ZrO2, Nb2O5, Bi2O3, MgO and La2O3.

[0008] This invention also provides a method for preparing a high-temperature bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material, comprising:

[0009] Step S1: Ingredient mixing; Weigh the raw materials according to the general stoichiometric ratio, mix and ball mill for 12 hours, and then dry to obtain powder;

[0010] Step S2: Pre-calcination; The powder dried in step S1 is mixed with a small amount of deionized water, pressed into blocks, placed in a crucible, and then pre-calcined in a muffle furnace to 850°C and held for 2 hours to obtain pre-calcined powder. After pre-calcination, the powder is coarsely crushed.

[0011] Step S3: Secondary ball milling; The powder obtained in step S2 is ball milled for 24 hours and then dried.

[0012] Step S4: Granulation and molding; Add 7wt% to 12wt% polyvinyl alcohol to the powder obtained in step S3, granulate and then sieve. Press the sieved powder into tablets using a tablet press to form a ceramic blank.

[0013] Step S5: Debinding; The ceramic blank obtained in step S4 is placed in a muffle furnace for debinding to obtain a debinded ceramic blank;

[0014] Step S6: Sintering; The ceramic blank obtained in step S5 after debinding is placed in a muffle furnace, covered with zirconium dioxide powder for burial and firing, and then naturally cooled to room temperature to obtain ceramic sheets.

[0015] Preferably, in step S2, the preheating rate is 3°C / min to 8°C / min.

[0016] Preferably, in step S5, the glue discharge temperature is 600℃ and the glue discharge heat preservation time is 2h.

[0017] Preferably, the sintering temperature rise and fall parameters include: rising to 1000℃~1100℃ at a rising rate of 3℃ / min~5℃ / min, holding at that temperature for 2 hours, and then cooling down to 800℃ at a falling rate of 3℃ / min~8℃ / min after the holding period, and then naturally cooling to room temperature.

[0018] Preferably, after step S6, the method further includes:

[0019] Step S7: Polishing; The ceramic sheet is machined, polished, and cleaned;

[0020] Step S8: Silver electrode firing; Brush silver electrodes onto the surface of the ceramic sheet that needs to be polarized, and then place it in a muffle furnace to fire silver, thus obtaining a silver-plated ceramic sheet.

[0021] Step S9: Polarization; The ceramic sheet obtained in step S8 is polarized. The polarization process is as follows: the electric field strength is 4kv / mm to 5kv / mm, the polarization temperature is 120℃, and the polarization time is 10min to 30min.

[0022] Preferably, in step S8, the silver is heated to 650°C to 800°C at a rate of 3°C / min to 10°C / min, and held at this temperature for 20 min to 40 min.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] This invention relates to a high-temperature piezoelectric ceramic 0.65Bi(Mg) 0.51 Ti 0.49 O3-0.35Pb(Zr) x Ti 1-x This high-temperature piezoelectric ceramic, containing ywt% La₂O₃, exhibits a higher Curie temperature of 460-520℃ and can operate in high-temperature environments of 260-400℃. It possesses high piezoelectric properties. 33 With a strength of ~170pC / N, it can be applied to high-temperature piezoelectric sensors, drivers, and other applications. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to specific embodiments. The advantages and features of the present invention will become clearer from the following description.

[0026] Example 1

[0027] This invention relates to a bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material with the general chemical formula 0.65Bi(Mg) 0.51 Ti 0.49 O3-0.35Pb(Zr) x Ti 1-x )O3-0.05wt%La2O3, where x=0.25.

[0028] Specifically, the preparation methods include the following:

[0029] S1: Weigh the ingredients according to the chemical formula ratio, add deionized water, mix and ball mill, and then dry after ball milling for 12 hours.

[0030] S2: The dried powder is mixed with a small amount of water and pressed into blocks, placed in a crucible, and then pre-fired in a muffle furnace. The pre-firing heating rate is 3℃ / min, the pre-firing temperature is 850℃, and the pre-firing holding time is 2h. After pre-firing, the powder is coarsely crushed to obtain pre-fired powder.

[0031] S3: Secondary ball milling. The powder obtained in S2 is ball milled and dried for 24 hours. Then, a polyvinyl alcohol solution is added and ground evenly. The amount of polyvinyl alcohol is 8 wt%. The powder is then sieved through a 100-mesh sieve.

[0032] S4: Molding, the powder obtained in step S3 is pressed into tablets using a tablet press to form a ceramic blank.

[0033] S5: Debonding. The preform obtained in S4 is placed in a muffle furnace for debonding. The debonding temperature is 600℃ and the debonding holding time is 2h. The debonded preform is then obtained.

[0034] S6: Sintering. The debinding body obtained in S5 is placed in a muffle furnace and covered with zirconium dioxide powder for sintering. The sintering temperature regulation is as follows: the temperature is increased to 1000℃ at a rate of 3℃ / min and held for 1 hour. Then, the temperature is increased to 1160℃ at a rate of 2℃ / min and held for 3 hours. After the holding period, the temperature is reduced to 800℃ at a rate of 4℃ / min and then naturally cooled to room temperature to obtain ceramic sheets.

[0035] S7: Polishing. The ceramic obtained in S6 is machined and then polished to form the designed shape, and then cleaned.

[0036] S8: Silver electrode firing. Apply the silver electrode to the ceramic surface that needs to be polarized using S7, and then place it in a muffle furnace to fire the silver. The silver firing steps are as follows: raise the temperature to 800℃ at a rate of 3℃ / min, and hold at this temperature for 30min to obtain the silver-coated ceramic sheet.

[0037] S9: Polarization. The ceramic obtained in S8 was polarized with silicone oil at a polarization voltage of 4 kV / mm and a polarization temperature of 120℃ for 20 min. After polarization, it was cleaned to obtain a high-power lead manganese niobate-lead zirconate titanate piezoelectric ceramic material. The ceramic was then tested after being left to stand for 24 hours.

[0038] Example 2

[0039] The only difference between this embodiment and Embodiment 1 is that its chemical formula is 0.65Bi(Mg). 0.51 Ti 0.49 O3-0.35Pb(Zr) x Ti 1-x )O3-0.05wt%La2O3, where x=0.4.

[0040] Example 3

[0041] The only difference between this embodiment and Embodiment 1 is that its chemical formula is 0.65Bi(Mg). 0.51 Ti 0.49 O3-0.35Pb(Zr) x Ti 1-x )O3-0.05wt%La2O3, where x=0.55.

[0042] Example 4

[0043] The only difference between this embodiment and Embodiment 1 is that its chemical formula is 0.65Bi(Mg).0.51 Ti 0.49 O3-0.35Pb(Zr) 0.25 Ti 0.75 )O3-ywt%La2O3, where y=0.25.

[0044] Example 5

[0045] The only difference between this embodiment and Embodiment 1 is that its chemical formula is 0.65Bi(Mg). 0.51 Ti 0.49 O3-0.35Pb(Zr) 0.25 Ti 0.75 )O3-ywt%La2O3, where y=0.55.

[0046] Example 6

[0047] The only difference between this embodiment and Embodiment 1 is that its chemical formula is 0.65Bi(Mg). 0.51 Ti 0.49 O3-0.35Pb(Zr) 0.25 Ti 0.75 )O3-ywt%La2O3, where y=0.85.

[0048] The electrical performance test results of Examples 1 to 3 are shown in Table 1 below.

[0049] Table 1. Data on piezoelectric and dielectric properties.

[0050] Example Components <![CDATA[d 33 (pC / N)]]> kp <![CDATA[ε r ]]> Tc (°C) Example 1 x＝0.25 172 0.30 985 513 Example 2 x＝0.4 150 0.31 851 490 Example 3 x＝0.55 120 0.32 808 472

[0051] The electrical performance test results of Examples 4 to 6 above are shown in Table 2 below.

[0052] Table 2. Data on piezoelectric and dielectric properties.

[0053] Example Components <![CDATA[d 33 (pC / N)]]> kp <![CDATA[ε r ]]> Tc (°C) Example 4 y＝0.25 180 0.31 1030 491 Example 5 y＝0.55 142 0.27 811 486 Example 6 y＝0.85 80 0.20 608 477

[0054] In summary, this invention designs a 0.65Bi(Mg) magnesium bismuth titanate-lead zirconate titanate high-temperature piezoelectric ceramic material. 0.51 Ti 0.49 O3-0.35Pb(Zr) x Ti 1-x The novel piezoelectric ceramic system, containing ywt% La2O3, exhibits a higher Curie temperature of 460℃~520℃ and can operate in high-temperature environments ranging from 260℃~400℃. It is suitable for application in high-temperature sensor piezoelectric devices.

[0055] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A high-temperature bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material, characterized in that, Its general chemical formula is represented as 0.65Bi(Mg) 0.51 Ti 0.49 O3-0.35Pb(Zr) x Ti 1-x )O3-ywt%La2O3; where x = 0.01~0.7, y = 0.01~2.

2. The high-temperature bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material as described in claim 1, characterized in that, The values ​​are x = 0.25 to 0.55 and y = 0.25 to 0.

85.

3. The high-temperature bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material as described in claim 1, characterized in that, The raw materials for preparing the piezoelectric ceramic material include Pb3O4, TiO2, ZrO2, Nb2O5, Bi2O3, MgO and La2O3.

4. A method for preparing a high-temperature bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material, characterized in that, include: Step S1: Ingredient mixing; Weigh the raw materials according to the general stoichiometric ratio, mix and ball mill for 12 hours, and then dry to obtain powder; Step S2: Pre-calcination; The powder dried in step S1 is mixed with a small amount of deionized water, pressed into blocks, placed in a crucible, and then pre-calcined in a muffle furnace to 850°C and held for 2 hours to obtain pre-calcined powder. After pre-calcination, the powder is coarsely crushed. Step S3: Secondary ball milling; The powder obtained in step S2 is ball milled for 24 hours and then dried. Step S4: Granulation and molding; Add 7wt% to 12wt% polyvinyl alcohol to the powder obtained in step S3, granulate and then sieve. Press the sieved powder into tablets using a tablet press to form a ceramic blank. Step S5: Debinding; The ceramic blank obtained in step S4 is placed in a muffle furnace for debinding to obtain a debinded ceramic blank; Step S6: Sintering; The ceramic blank obtained in step S5 after debinding is placed in a muffle furnace, covered with zirconium dioxide powder for sintering, and then naturally cooled to room temperature to obtain ceramic sheets.

5. The preparation method of a high-temperature bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material as described in claim 4, characterized in that, In step S2, the preheating rate is 3°C / min to 8°C / min.

6. The preparation method of a high-temperature bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material as described in claim 4, characterized in that, In step S5, the glue discharge temperature is 600℃ and the glue discharge heat preservation time is 2h.

7. The preparation method of a high-temperature bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material as described in claim 4, characterized in that, The sintering temperature and humidity parameters include: heating to 1000℃~1100℃ at a heating rate of 3℃ / min~5℃ / min, holding at that temperature for 2 hours, and then cooling down to 800℃ at a cooling rate of 3℃ / min~8℃ / min after the holding period, followed by natural cooling to room temperature.

8. The preparation method of a high-temperature bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material as described in claim 4, characterized in that, Following step S6, the method further includes: Step S7: Polishing; The ceramic sheet is machined, polished, and cleaned; Step S8: Silver electrode firing; Brush silver electrodes onto the surface of the ceramic sheet that needs to be polarized, and then place it in a muffle furnace to fire silver, thus obtaining a silver-plated ceramic sheet. Step S9: Polarization; The ceramic sheet obtained in step S8 is polarized. The polarization process is as follows: the electric field strength is 4kv / mm to 5kv / mm, the polarization temperature is 120℃, and the polarization time is 10min to 30min.

9. The preparation method of a high-temperature bismuth magnesium titanate-lead zirconate titanate piezoelectric ceramic material as described in claim 8, characterized in that, In step S8, the silver is heated to 650°C to 800°C at a rate of 3°C / min to 10°C / min, and held at this temperature for 20 min to 40 min.