Compression type piezoelectric high temperature acceleration sensor

Abstract

The application discloses a compression piezoelectric high-temperature acceleration sensor, which comprises a core body, a shell and a plug; the core body comprises a base, a mass block, N electrode sheets, two insulating sheets, a fastening device and N-1 ceramic sheets; the compression piezoelectric high-temperature acceleration sensor keeps the sensitive deviation within ±5% in the range from room temperature to 500 DEG C, and the impedance is as high as 10 7 , and can stably work at 500 DEG C.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of acceleration sensors, and particularly relates to a compression type piezoelectric high-temperature acceleration sensor. BACKGROUND

[0002] An acceleration sensor is an inertial sensor capable of measuring acceleration force. Common types of acceleration sensors include piezoelectric, piezoresistive, capacitive and strain types. The piezoelectric acceleration sensor is widely concerned due to its advantages of good sensitivity, small size and light weight, and is widely applied in the fields of automobile industry, aerospace and medical care. In practical application, the piezoelectric acceleration sensor often needs to work for a long time in a high-temperature environment. However, the existing piezoelectric acceleration sensor is greatly affected by temperature, and generally has a large deviation at high temperature. For example, a high-temperature acceleration sensor prepared by using sodium bismuth titanate high-temperature piezoelectric ceramic material as a piezoelectric element is disclosed in Chinese Patent No. CN112851336A. The sensitivity deviation of the sensor will become larger and larger with the increase of temperature, and the sensitivity deviation at high temperature is far more than ±5%. Therefore, it is urgent to develop an acceleration sensor with good sensitivity and small sensitivity deviation at high temperature. SUMMARY

[0003] In view of the deficiencies of the prior art, the application aims to provide a compression type piezoelectric high-temperature acceleration sensor.

[0004] Another object of the application is to provide a bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic material, which effectively improves the piezoelectric performance while maintaining a high Curie temperature and excellent high-temperature resistivity.

[0005] Another object of the application is to provide a preparation method of a bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic material. The preparation method dopes and modifies the bismuth layer structure sodium bismuth titanate piezoelectric ceramic material (Na 0.5 Bi 4.5 Ti4O 15 ceramics) by using Nb and Sr elements.

[0006] Another object of the application is to provide an application of the bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic material in an acceleration sensor.

[0007] The application aims to achieve the above objects by the following technical solutions.

[0008] A bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic material, a general formula of the bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic material is Na 0.5 Bi 4.5 Ti 4-x Nb x O 15+x / 2: Sr, the ratio of Sr to Na 0.5 Bi 4.5 Ti 4-x Nb x O 15+x / 2 is 0.02:1, and 0.04≤x≤0.08.

[0009] A preparation method of a bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material, comprising the following steps:

[0010] Step 1, mixing a Na source, a Bi source, a Ti source, a Nb source and a Sr source, ball milling to obtain a mixed raw material, pre-sintering the mixed raw material at 750-800 ℃ for 2-4 h, and cooling to room temperature to obtain a pre-sintered powder, wherein the ratio of Na in the Na source, Bi in the Bi source, Ti in the Ti source, Nb in the Nb source and Sr in the Sr source is 0.5:4.5:(4-x):x:0.02 in terms of the amount of substance.

[0011] In the step 1, the Na source is Na2CO3, the Bi source is Bi2O3, the Ti source is TiO2, the Nb source is Nb2O5, and the Sr source is SrCO3.

[0012] In the step 1, the rate of temperature rise to 750-800 ℃ is 3-5 ℃ / min.

[0013] Step 2, grinding the pre-sintered powder, sieving, secondary ball milling, granulating, and molding to obtain a blank;

[0014] In the step 2, the binder for the granulation is a polyvinyl alcohol (PVA) solution, the polyvinyl alcohol solution is a mixture of polyvinyl alcohol and water, and the concentration of polyvinyl alcohol in the polyvinyl alcohol solution is 5-7 wt%.

[0015] In the granulation of the step 2, the polyvinyl alcohol solution is 7-10 wt% of the pre-sintered powder.

[0016] In the step 1 and the step 2, the ball milling is wet milling, the medium for the wet milling is anhydrous ethanol, and the ball milling beads are agate balls.

[0017] In the above technical solution, the wet milling is followed by drying, grinding and sieving.

[0018] In the step 1 and the step 2, the temperature for the drying is 80-100 ℃, and the time for the drying is 3-5 h.

[0019] In the step 1 and the step 2, the time for the ball milling is 6-8 h, and the rate for the ball milling is 250-300 r / min.

[0020] In the ball milling of the step 1, the ratio of the agate ball, the mixed raw material and the anhydrous ethanol is (0.8-1.0):(0.6-0.7):(0.5-0.7) by mass fraction.

[0021] In the step 2, the forming operation includes: firstly, using a tablet press to press into a cylindrical embryo, and then forming in a cold isostatic press.

[0022] In the above technical solution, the pressure for pressing into a cylindrical embryo is 2-5 MPa, and the time for pressing into a cylindrical embryo is 30-60 s.

[0023] In the above technical solution, the pressure for forming in the cold isostatic press is 280-300 MPa, and the time is 10-30 s.

[0024] In the step 1 and the step 2, the screen mesh of the sieving is 60-80 mesh.

[0025] In step 3, the embryo is degreased, sintered at 1050-1090 DEG C for 3-5 h to obtain a ceramic column, and sliced to obtain a ceramic sheet, which is sequentially subjected to double-sided electrode, electrode sintering, and polarization in silicon oil to obtain a bismuth-layered sodium bismuth titanate high-temperature piezoelectric ceramic material.

[0026] In the step 3, the degreasing includes: heat preservation at 550-600 DEG C for 2-4 h, and natural cooling to room temperature.

[0027] In the step 3, the heating rate of the degreasing is 3-5 DEG C / min.

[0028] In the step 3, the thickness of the ceramic sheet is 0.6-0.8 mm.

[0029] In the step 3, the ceramic sheet is subjected to double-sided silver treatment by screen printing.

[0030] In the step 3, the temperature of the electrode sintering is 750-800 DEG C, and the time of the electrode sintering is 20-30 min.

[0031] In the step 3, the temperature of the silicon oil is 170-200 DEG C, the field strength of the polarization is 8-10 kV / mm, and the time of the polarization is 20-30 min.

[0032] The bismuth-layered sodium bismuth titanate high-temperature piezoelectric ceramic material is applied to an acceleration sensor.

[0033] A compression type piezoelectric high-temperature acceleration sensor, comprising: a core, a shell and a plug.

[0034] The shell is a cavity, the core is installed in the cavity, and the plug is fixed on the shell.

[0035] The core includes: a base, a mass block, N electrode plates, two insulating plates, a fastening device, and N-1 ceramic plates;

[0036] The base is used to fix it to the shell. A column is formed on the base, and N electrode plates, two insulating plates and N-1 ceramic plates are sleeved on the column.

[0037] Each of the electrode plates is set horizontally, and a ceramic plate is set between every two adjacent electrode plates. An insulating plate is set above the uppermost electrode plate and below the lowermost electrode plate. The mass block is fitted on the column and located on the uppermost insulating plate.

[0038] The fastening device is connected to the column above the mass block and is used to press N electrode plates, two insulating plates and N-1 ceramic plates onto the base. The ceramic plates are the bismuth layered sodium titanate high-temperature piezoelectric ceramic material.

[0039] In the above technical solution, the plug is located on the top or side of the housing.

[0040] In the above technical solution, the N electrode sheets, two insulating sheets, and N-1 ceramic sheets have the same structure, all of which are ring-shaped.

[0041] In the above technical solution, the thickness of each ceramic sheet is 0.6 mm.

[0042] In the above technical solution, starting from top to bottom, odd-numbered electrode plates are connected in series and then connected to the positive terminal of the plug via wires, while even-numbered electrode plates are connected in series and then connected to the negative terminal of the plug via wires.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] (1) The preparation method of this invention selects Nb and Sr elements to form a bismuth layered structure sodium bismuth titanate piezoelectric ceramic material (Na). 0.5 Bi 4.5 Ti4O 15 Ceramics) undergoing ion substitution (for Bi) 3+ and Ti 4+ By performing partial ion substitution, the piezoelectric properties and resistivity of the bismuth layered sodium bismuth titanate high-temperature piezoelectric ceramic material were improved while maintaining a high Curie temperature. The dielectric loss of the bismuth layered sodium bismuth titanate high-temperature piezoelectric ceramic material was 0.0037, the Curie temperature was 669℃, the piezoelectric constant was 31.5 pC / N, and the mechanical quality factor Q was [missing information]. m The electromechanical coupling coefficient k is 3576. p It has a resistivity of 15.2% and a high-temperature resistivity of 5.7*10 at 500℃. 7 With an Ω·cm osmium layered sodium bismuth titanate high-temperature piezoelectric ceramic material, it has broad application prospects in the field of high-temperature piezoelectric devices.

[0045] (2) The preparation method is simple in process, low in cost, suitable for large-scale industrial production, and has a wide application prospect.

[0046] (3) The high-temperature piezoelectric ceramic material of the bismuth layer sodium bismuth titanate of the application has a high impedance of 10 7 , and can work stably at 500 DEG C. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 XRD patterns of the bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic materials prepared for Example 2, Example 6, Example 10, Example 14 and Example 18;

[0048] Figure 2 are scanning electron microscope (SEM) images, wherein (a) is the bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic material prepared for Example 2, (b) is the bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic material prepared for Example 6, (c) is the bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic material prepared for Example 10, (d) is the bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic material prepared for Example 14, and (e) is the bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic material prepared for Example 18;

[0049] Figure 3 is a diagram of the change of the dielectric constant of the bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic material prepared for Example 14 with temperature;

[0050] Figure 4 is a diagram of the change of the piezoelectric constant of the bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic materials prepared for Example 2, Example 6, Example 10, Example 14, Example 18 and Comparative Examples 1-2 with temperature;

[0051] Figure 5 is a diagram of the change of the resistivity of the bismuth layer sodium bismuth titanate high-temperature piezoelectric ceramic materials prepared for Example 2, Example 6, Example 10, Example 14, Example 18 and Comparative Examples 1-2 with temperature;

[0052] Figure 6 is a sectional view of a compression type piezoelectric high-temperature acceleration sensor (the plug is located at the side surface of the shell);

[0053] Figure 7 is a sectional view of a compression type piezoelectric high-temperature acceleration sensor (the plug is located at the top surface of the shell).

[0054] Wherein, 1: shell, 2: plug, 3: core, 3-1: base, 3-2: mass, 3-3: electrode sheet, 3-4: insulating sheet, 3-5: ceramic sheet, 3-6: column, 3-7: fastening device. DETAILED DESCRIPTION

[0055] The technical solutions of the present application are further described in detail below in combination with the drawings and examples.

[0056] In the following examples, Na2CO3, Bi2O3, TiO2, Nb2O5 and SrCO3 are all analytically pure.

[0057] Examples 1-20

[0058] A preparation method of a bismuth layer-type sodium bismuth titanate high-temperature piezoelectric ceramic material, comprising the following steps:

[0059] Step 1, mix the Na source, Bi source, Ti source, Nb source and Sr source in a ball mill jar to obtain a mixed raw material, add anhydrous ethanol and ball milling beads (agate balls) to the mixed raw material, the mass ratio of agate balls, mixed raw material and anhydrous ethanol is 1.0:0.7:0.5, mill at 300 r / min for 8 h, dry in a 100℃ oven for 5 h after ball milling, grind with a mortar, pass through a 60 mesh sieve, place the sieved powder in an alumina crucible, compact, cover, seal with zirconia powder to prevent Bi source volatilization, place the sealed alumina crucible in a muffle furnace, heat at a rate of 5℃ / min to 800℃ and pre-sinter at 800℃ for 3 h, naturally cool to room temperature, obtain a pre-sintered powder, wherein the ratio of Na in the Na source, Bi in the Bi source, Ti in the Ti source, Nb in the Nb source and Sr in the Sr source is D in terms of mole fraction, the Na source is Na2CO3, the Bi source is Bi2O3, the Ti source is TiO2, the Nb source is Nb2O5 and the Sr source is SrCO3;

[0060] Step 2, grind the pre-sintered powder, pass through a 60 mesh sieve, secondary ball mill at 300 r / min for 8 h, dry at 100℃ for 5 h after ball milling, grind, pass through a 60 mesh sieve, granulate the sieved powder with a 5wt% polyvinyl alcohol (PVA) solution (polyvinyl alcohol solution is a mixture of polyvinyl alcohol and water), the polyvinyl alcohol solution is 9wt% of the pre-sintered powder, take 7g of the granulated powder and place it in a die with a diameter of 13mm, press into a columnar green body in a tablet press with a pressure of 2Mpa for 30s, then shape in a cold isostatic press with a pressure of 300Mpa for 10s, obtain a green part;

[0061] Step 3, the embryo piece is heated to 600℃ at a heating rate of 5℃ / min and degassed at 600℃ for 2h, naturally cooled to room temperature, sintered at W℃ for 3h, to obtain a ceramic column, slicing to obtain a ceramic sheet with a thickness of 0.6mm, the ceramic sheet is treated with silver on both sides by screen printing (electrode), electrode sintering at 800℃ for 20min, after sintering, polarization in silicon oil at 190℃ for 30min at a polarization field strength of 10kV / mm, to obtain a bismuth layer structured sodium bismuth titanate high temperature piezoelectric ceramic material.

[0062] The D and W of the bismuth layer structured sodium bismuth titanate high temperature piezoelectric ceramic materials prepared in Examples 1-20 are shown in Table 1.

[0063] Table 1

[0064]

[0065]

[0066] Comparative Example 1

[0067] A method for preparing a bismuth layer structured sodium bismuth titanate high temperature piezoelectric ceramic material is basically the same as that of Example 14, the only difference being that the mixed raw materials, in Comparative Example 1, are Na source, Bi source, Ti source and Nb source, and the ratio of Na in the Na source, Bi in the Bi source, Ti in the Ti source and Nb in the Nb source is 0.5:4.5:3.94:0.06 in terms of the amount of substance.

[0068] Comparative Example 2

[0069] A method for preparing a bismuth layer structured sodium bismuth titanate high temperature piezoelectric ceramic material is basically the same as that of Example 14, the only difference being that the mixed raw materials, in Comparative Example 2, are Na source, Bi source, Ti source, Nb source and Sr source, and the ratio of Na in the Na source, Bi in the Bi source, Ti in the Ti source, Nb in the Nb source and Sr in the Sr source is 0.49:4.41:3.94:0.06:0.02 in terms of the amount of substance.

[0070] Figure 1 XRD patterns of the bismuth layer structured sodium bismuth titanate high temperature piezoelectric ceramic materials prepared in Example 2, Example 6, Example 10, Example 14 and Example 18. Figure 1 It can be seen that the crystal face indices of the strongest peaks in the XRD patterns of the bismuth layer structured sodium bismuth titanate high temperature piezoelectric ceramic materials prepared in Example 2, Example 6, Example 10, Example 14 and Example 18 are all (119), which is consistent with the bismuth layer structured sodium bismuth titanate piezoelectric ceramic material (Na 0.5 Bi 4.5 Ti4O 15The crystal face index (119) of the strongest peak of the ceramic) is consistent, indicating that the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic materials prepared in Examples 2, 6, 10, 14 and 18 are all typical bismuth layer-structured orthorhombic structures.

[0071] The bismuth layer-structured material has a bismuth layer-structured orthorhombic structure, and the surface energy along the c-axis direction is much lower than that in the a-b plane, resulting in that the growth rate of the grain along the a-b plane is much greater than that along the c-axis direction. Generally, a relatively flat sheet structure is formed in the a-b plane, and finally a flat plate grain is formed. As shown in FIG. 2, the scanning electron microscope (SEM) images of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic materials prepared in Examples 2, 6, 10, 14 and 18 show that the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic materials prepared in Examples 2, 6, 10, 14 and 18 have good density and no large holes, and all exhibit typical flat plate grains of bismuth layer-structured materials. Figure 2 Figure 2

[0072] At room temperature, the piezoelectric properties (piezoelectric constant d 33 , dielectric loss tanδ, Curie temperature T C , dielectric constant ε r , electromechanical coupling coefficient k p and mechanical quality factor Q m ) of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic materials prepared in Examples 1-20 and Comparative Examples 1-2 were tested, and the test results are shown in Table 2.

[0073] Table 2

[0074]

[0075]

[0076] As shown in Table 2, compared with Comparative Examples 1-2, the piezoelectric constant (d 33 ) of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic materials prepared in Examples 9-11, 13-15 and 17-19 is improved, and is all above 20 pC / N, wherein the piezoelectric constant of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 14 is as high as 31.5 pC / N, and all maintains a good Curie temperature. Therefore, the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared by the preparation method of the present application has an improved piezoelectric constant (d 33 ) without reducing the Curie temperature.

[0077] Figure 3 FIG. 4 is a diagram of the dielectric constant of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 14 changing with temperature.​​Figure 3 It can be seen that the dielectric constant ε of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 14 is 1 1 1.6 at room temperature, increases slowly in the range of room temperature to 500℃, increases sharply after 600℃, and decreases after 669℃, so the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 14 can be used stably in the range of 500℃. r It can be seen that the dielectric constant ε of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 14 is 1 1 1.6 at room temperature, increases slowly in the range of room temperature to 500℃, increases sharply after 600℃, and decreases after 669℃, so the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 14 can be used stably in the range of 500℃.

[0078] Figure 4 The piezoelectric constant d of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 2, Example 6, Example 10, Example 14, Example 18 and Comparative Examples 1-2 changes with temperature. It can be seen from the figure that the piezoelectric constant d of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 2 is 18.6 pC / N at room temperature, decreases slowly in the range of room temperature to 500℃, and decreases sharply after 500℃, so the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 2 cannot be used at high temperature. Figure 4 It can be seen that the piezoelectric constant d of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 10, Example 14 and Example 18 is relatively stable with the increase of temperature, and the piezoelectric constant d of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 14 still remains at 30.6 pC / N at 500℃, which can meet the application requirements at high temperature. 33 It can be seen that the piezoelectric constant d of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 10, Example 14 and Example 18 is relatively stable with the increase of temperature, and the piezoelectric constant d of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 14 still remains at 30.6 pC / N at 500℃, which can meet the application requirements at high temperature.

[0079] Figure 5 The resistivity of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 2, Example 6, Example 10, Example 14, Example 18 and Comparative Examples 1-2 changes with temperature. It can be seen from the figure that the resistivity of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 2 is 9.0*10 Figure 5 Ω·cm at 500℃, the resistivity of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 6 is 1.2*10 5 Ω·cm, the resistivity of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 10 is 3.6*10 7 Ω·cm, the resistivity of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 18 is 4.2*10 7 Ω·cm, the resistivity of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Comparative Example 1 is 6.0*10 7 Ω·cm, the resistivity of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Comparative Example 2 is 4.6*10 6 Ω·cm, and the resistivity of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 14 is still as high as 5.7*10 6 Ω·cm at 500℃, and the resistivity of the bismuth layer-structured sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 10, Example 14 and Example 18 all remains above 10 7 Ω·cm at high temperature, so it has great potential in high-temperature application. 7 Ω·cm at high temperature, so it has great potential in high-temperature application.

[0080] Example 21

[0081] A compression-type piezoelectric high-temperature accelerometer was assembled using the bismuth layered sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 14 as the core element (i.e., the piezoelectric element). The compression-type piezoelectric high-temperature accelerometer is as follows: Figure 6 and Figure 7 As shown, it includes: a core 3, a housing 1, and a plug 2. The housing 1 is a cavity, and the core 3 is installed inside the cavity. The plug 2 is fixedly mounted on the housing 1. The core 3 includes: a base 3-1, a mass block 3-2, N electrode plates 3-3, two insulating plates 3-4, a fastening device, and N-1 ceramic plates 3-5 (piezoelectric elements). The base 3-1 is used for fixed mounting to the housing 1. A column 3-6 is formed on the base 3-1. The N electrode plates 3-3, the two insulating plates 3-4, and the N-1 ceramic plates 3-5 are fitted onto the column 3-6. Each electrode plate 3-3 is horizontally positioned. A ceramic plate 3-5 is placed between every two adjacent electrode plates 3-3. An insulating plate 3-4 is placed above the uppermost electrode plate 3-3 and below the lowermost electrode plate 3-3. A mass block 3-2 is fitted onto the column 3-6 and located on the uppermost insulating plate 3-4. A fastening device 3-7 is connected to the column 3-6 above the mass block 3-2 and is used to press N electrode plates 3-3, two insulating plates 3-4 and N-1 ceramic plates 3-5 onto the base 3-1. For example, the fastening device 3-7 can be a bolt and connected to the column 3-6 by threads.

[0082] Preferably, the plug 2 is located on the top or side surface of the housing 1. Figure 6 As shown, plug 2 is located on the side of housing 1; Figure 7 As shown, plug 2 is located on the top surface of housing 1.

[0083] Preferably, the N electrode plates 3-3, the two insulating plates 3-4, and the N-1 ceramic plates 3-5 have the same structure, all being ring-shaped. In this embodiment, the inner diameter of the ring is 4.2 mm and the outer diameter is 9.6 mm.

[0084] Each ceramic sheet 3-5 has a thickness of 0.6 mm. Ceramic sheets 3-5 are the bismuth layered sodium bismuth titanate high-temperature piezoelectric ceramic material prepared in Example 14.

[0085] Starting from the top, the odd-numbered electrode plates 3-3 are connected in series and then connected to the positive terminal of plug 2 via a wire, while the even-numbered electrode plates 3-3 are connected in series and then connected to the negative terminal of plug 2 via a wire.

[0086] In the embodiment, N=6 or 7. The sensitivity and impedance performance of the compression type piezoelectric high-temperature acceleration sensor are tested by a dynamic analyzer in the range of 25-500 ℃, and the test results are shown in Table 3. It is shown from the results in Table 3 that the sensitivity deviation of the compression type piezoelectric high-temperature acceleration sensor in the range of 25-500 ℃ is within ±5%, and the impedance of the compression type piezoelectric high-temperature acceleration sensor is kept above 10 7 Ω after being kept at 500 ℃ for one hour, so that the compression type piezoelectric high-temperature acceleration sensor can stably output charges at 500 ℃.

[0087] Table 3

[0088]

[0089]

[0090] The above has exemplarily described the present application, and it should be indicated that any simple transformation, modification or other equivalent replacement without creative labor of those skilled in the art without departing from the core of the present application falls into the protection scope of the present application.

Claims

1. A compression type piezoelectric high temperature acceleration sensor characterized by comprising: The utility model relates to a core, a shell and a plug. The shell is a cavity, the core is installed in the cavity, and the plug is fixed on the shell. The core comprises a base, a mass block, N electrode sheets, two insulating sheets, a fastening device and N-1 ceramic sheets. The base is used for being installed in cooperation with the shell, a column is formed on the base, the N electrode sheets, the two insulating sheets and the N-1 ceramic sheets are sleeved on the column, each of the electrode sheets is horizontally arranged, one ceramic sheet is arranged between every two adjacent electrode sheets, one insulating sheet is arranged above the uppermost electrode sheet and below the lowermost electrode sheet, and the mass block is sleeved on the column and located on the uppermost insulating sheet. The fastening device is screwed on the column of the base and is used for pressing the N electrode sheets, the two insulating sheets and the N-1 ceramic sheets on the base. The plug is located on the top surface or the side surface of the shell. The N electrode sheets, the two insulating sheets and the N-1 ceramic sheets have the same structure and are annular, and the thickness of each ceramic sheet is 0.6 mm. The general formula of the bismuth layer bismuth sodium titanate high-temperature piezoelectric ceramic material is Na 0.5 Bi 4.5 Ti 4-x Nb x O 15+x / 2 : Sr, the ratio of Sr to Na 0.5 Bi 4.5 Ti 4-x Nb x O 15+x / 2 is 0.02:1, and x=0.

06.

2. The compression-type piezoelectric high-temperature acceleration sensor according to claim 1, characterized by Starting from top to bottom, the odd electrode sheets are connected in series and connected with the positive pole of the plug through wires, and the even electrode sheets are connected in series and connected with the negative pole of the plug through wires.

3. The compression-type piezoelectric high-temperature acceleration sensor according to claim 1, characterized by The preparation method of the bismuth layer bismuth sodium titanate high-temperature piezoelectric ceramic material comprises the following steps:

4. The compression mode piezoelectric high temperature acceleration sensor according to claim 1, characterized by Step 2, grinding, sieving, secondary ball milling, granulating, molding the pre-sintering powder to obtain a blank; 5. The compression mode piezoelectric high temperature acceleration sensor according to claim 1, characterized by Step 3, degassing the blank, sintering at 1050-1090 DEG C for 3-5 h to obtain a ceramic column, slicing to obtain ceramic sheets, and sequentially performing double-sided electrode, electrode sintering and silicon oil polarization on the ceramic sheets to obtain the bismuth layer bismuth sodium titanate high-temperature piezoelectric ceramic material. Step 1, mixing a Na source, a Bi source, a Ti source, a Nb source and a Sr source, ball milling to obtain a mixed raw material, pre-sintering the mixed raw material at 750-800 ℃ for 2-4 h, cooling to room temperature to obtain a pre-sintered powder, wherein the ratio of Na in the Na source, Bi in the Bi source, Ti in the Ti source, Nb in the Nb source and Sr in the Sr source is 0.5:4.5:(4- x ): x :0.02 in terms of the amount of substance. The Na source is Na2CO3, the Bi source is Bi2O3, the Ti source is TiO2, the Nb source is Nb2O5, and the Sr source is SrCO3. The binder for granulation is a polyvinyl alcohol solution, the concentration of polyvinyl alcohol in the polyvinyl alcohol solution is 5-7 wt%, and the polyvinyl alcohol solution is 7-10 wt% of the pre-sintering powder.

6. The compression mode piezoelectric high temperature acceleration sensor according to claim 5, characterized by The degassing comprises the following steps: keeping at 550-600 DEG C for 2-4 h and naturally cooling to room temperature.

7. The compression mode piezoelectric high temperature acceleration sensor according to claim 5, characterized by The electrode sintering temperature is 750-800 DEG C, and the electrode sintering time is 20-30 min.

8. The compression mode piezoelectric high temperature acceleration sensor according to claim 5, characterized by The temperature of the silicon oil is 170-200 DEG C, the polarization field strength is 8-10 kV / mm, and the polarization time is 20-30 min.

9. The compression mode piezoelectric high temperature acceleration sensor according to claim 5, characterized by ​ 10. The compression mode piezoelectric high temperature acceleration sensor according to claim 5, characterized by ​

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