Multifunctional piezoelectric ceramic electrical property test cavity

Abstract

The invention discloses a multifunctional piezoelectric ceramic electrical property test cavity, which comprises a metal upper cover (1) and a metal cavity (2), and is characterized in that a sample table consisting of an upper cover (5) and a carrying table (6) is arranged at the bottom in the metal cavity (2); a heating wire is arranged in the carrying table (6); a mechanical clamping assembly (30) for fixing a sample is arranged at the inner bottom of the metal cavity (2); the circumferential side surface of the metal cavity (2) is provided with an extraction opening (24), a water inlet (22), a water outlet (23) and a wiring port; a silicon dioxide wafer (3) is arranged at the top end of the metal upper cover (1); the wiring port is electrically connected with the mechanical clamping assembly (30) and the heating wire. According to the invention, the clamping force on the sample, the ambient temperature of the sample and the air pressure environment in the cavity can be changed, the requirements on the electrical property test of the piezoelectric ceramic in various test environments can be simulated, and the stability and the application range of the piezoelectric ceramic can be better judged.

Description

Technical Field

[0001] The present invention relates to the field of testing equipment for the electrical properties of piezoelectric materials, and particularly to a multifunctional test cavity for the electrical properties of piezoelectric ceramics. Background Art

[0002] With the continuous development of piezoelectric materials and their theories, various measuring devices for measuring the properties of piezoelectric ceramics have been continuously developed. However, most of the current test cavities can only be tested under a single simulated environmental condition, and measuring devices under multiple complex environments have not been fully developed. At the same time, the background of variable force, variable air pressure, and variable temperature can detect the change of the electrical properties of piezoelectric ceramics with the environment, simulate the real working environment, and judge the stability and applicable range of piezoelectric ceramics.

[0003] The fixtures of common electrical property test devices cannot achieve precise control of the clamping force magnitude, and the magnitude of the clamping force of the fixture has a serious impact on the test results of the electrical properties of piezoelectric ceramics, so that the existing test platform requires a long time for calibration each time. The common variable temperature test system can only achieve heating and conduct electrical tests at high temperatures. Cooling can only be achieved by natural cooling, and the detection efficiency is low; secondly, it can only be tested in the air, cannot simulate a vacuum test environment, and is prone to oxidation of the cavity and fixture at high temperatures. Summary of the Invention

[0004] The purpose of the present invention is to provide a multifunctional test cavity for the electrical properties of piezoelectric ceramics. The present invention can change the clamping force on the sample, the temperature around the sample, and the air pressure environment in the cavity, and realize the need for testing the electrical properties of piezoelectric ceramics under a variety of test environments, which is convenient for better judging the stability and applicable range of piezoelectric ceramics.

[0005] The technical solution of the present invention: A multifunctional test cavity for the electrical properties of piezoelectric ceramics, including a metal upper cover and a metal cavity. The bottom of the metal cavity is provided with a sample stage composed of an upper cover and a carrier; a heating wire is arranged inside the carrier; the bottom of the metal cavity is provided with a mechanical clamping assembly for fixing the sample; the circumferential side of the metal cavity is provided with an air extraction port, a water inlet, a water outlet, and a wiring port; a silica wafer is arranged at the top of the metal upper cover; the wiring ports are electrically connected to the mechanical clamping assembly and the heating wire respectively.

[0006] In the above-mentioned multifunctional test cavity for the electrical properties of piezoelectric ceramics, the upper end of the metal cavity is connected to the metal upper cover through a threaded structure, and a rubber gasket is arranged at the upper end of the metal cavity.

[0007] In the aforementioned multifunctional piezoelectric ceramic electrical property testing cavity, the mechanical clamping assembly includes a fixture fixing rod disposed on the partition board. An upper fixture is connected to the fixture fixing rod through a bolt assembly, and a lower fixture for placing a sample is provided on the upper cover. A clamping force adjusting assembly is provided on the upper fixture, and the upper fixture and the lower fixture are connected to a wiring port through wires.

[0008] In the aforementioned multifunctional piezoelectric ceramic electrical property testing cavity, an alumina screw is provided at the upper end of the fixture fixing rod. Insulators disposed on both the upper and lower sides of the upper fixture are sleeved on the alumina screw, and an alumina nut is provided at the upper end of the alumina screw.

[0009] In the aforementioned multifunctional piezoelectric ceramic electrical property testing cavity, the clamping force adjusting assembly includes a fixing column passing through the upper fixture. An adjusting nut is provided at the upper end of the fixing column, and a spring is provided between the upper fixture and the lower part of the fixing column.

[0010] In the aforementioned multifunctional piezoelectric ceramic electrical property testing cavity, the metal upper cover is a metal upper cover with an attached annular handle.

[0011] In the aforementioned multifunctional piezoelectric ceramic electrical property testing cavity, the wiring port includes a wire passing port provided on the side of the metal cavity. A wiring terminal is provided in the wire passing port, and the wiring terminal is electrically connected to the upper fixture, the lower fixture, and the heating wire respectively.

[0012] In the aforementioned multifunctional piezoelectric ceramic electrical property testing cavity, a partition board is provided in the metal cavity. The air extraction port is provided above the partition board, and the water inlet and the water outlet are located below the partition board.

[0013] In the aforementioned multifunctional piezoelectric ceramic electrical property testing cavity, both the upper cover and the carrier table are made of alumina ceramic.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] 1. In the present invention, the sample to be tested is placed on the sample stage and fixed by the mechanical clamping assembly. The wiring port is energized, and the mechanical clamping assembly can adjust the clamping force of the upper fixture on the sample. The stage is internally provided with heating wires, and by heating up the heating wires, heating of the sample is achieved. The inlet and outlet water ports on both sides of the metal cavity allow the inflow and outflow of the cooling liquid, achieving cooling of the cavity, enabling rapid transformation of the temperature environment inside the cavity, and improving the detection efficiency. The air extraction port measured through the metal cavity can evacuate the metal cavity into a vacuum environment. At high temperatures, oxidation easily occurs between the metal cavity and the fixture. To eliminate the interference of this factor, the metal cavity is evacuated into a vacuum environment. The present invention can change the clamping force on the sample, the temperature around the sample, and the air pressure environment inside the cavity, meeting the requirements for testing the electrical properties of piezoelectric ceramics under various simulated test environments, and facilitating better judgment of the stability and applicable range of piezoelectric ceramics.

[0016] 2. The upper end of the metal cavity is connected to the metal upper cover through a threaded structure, and a rubber gasket is provided at the upper end of the metal cavity. This structure is convenient for connection, and the sealing performance of the cavity can be improved by setting the rubber gasket.

[0017] 3. When the clamping force adjustment assembly is in use, by rotating the adjustment nut, the fixed column generates vertical displacement, thereby adjusting the clamping force of the clamping end of the upper fixture on the sample. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the present invention;

[0019] Figure 2 is a schematic diagram of the mechanical clamping assembly.

[0020] Explanation of the reference numerals in the drawings: 1 - metal upper cover, 2 - metal cavity, 3 - silica wafer, 4 - rubber gasket, 5 - upper cover, 6 - stage, 7 - upper fixture, 8 - lower fixture, 9 - piezoelectric sample, 20 - wiring terminal, 21 - wire passing port, 22 - water inlet, 23 - water outlet, 24 - air extraction port, 25 - partition board, 26 - cooling pipe, 70 - fixed column, 71 - spring, 72 - adjustment nut, 73 - fixture fixing rod, 74 - alumina screw, 75 - insulator, 76 - alumina nut, 30 - mechanical clamping assembly, 31 - clamping force adjustment assembly. Detailed Embodiment

[0021] The present invention will be further described below in conjunction with the drawings and embodiments, but it shall not be used as a basis for limiting the present invention.

[0022] Embodiment: A multifunctional test cavity for the electrical properties of piezoelectric ceramics includes a metal upper cover 1 and a metal cavity 2, as shown in the attached Figure 1As shown in the figure, the upper end of the metal cavity 2 is connected to the metal upper cover 1 through a threaded structure, and a rubber gasket 4 is provided at the upper end of the metal cavity 2. This structure is convenient for connection, and the sealing performance of the cavity can be improved by setting the rubber gasket. The metal upper cover 1 is a metal upper cover 1 with a ring handle, which is convenient for taking the metal upper cover. A partition 25 is installed at the inner bottom of the metal cavity 2, and a sample stage composed of an upper cover 5 and a stage 6 is fixed on the partition 25. Both the upper cover 5 and the stage 6 are made of alumina ceramic. The piezoelectric sample 9 is placed on the sample stage, and a heating wire is built in the stage 6. A mechanical clamping assembly 30 for fixing the sample is provided at the inner bottom of the metal cavity 2. An air extraction port 24, a water inlet 22, a water outlet 23 and a wiring port are provided on the circumferential side of the metal cavity 2. The wiring port is electrically connected to the mechanical clamping assembly 30 and the heating wire respectively. The wiring port includes a wire passing port 21 provided on the side of the metal cavity 2, and a wiring terminal 20 provided in the wire passing port 21. The wiring terminal 20 is electrically connected to the upper clamp 7, the lower clamp 8 and the heating wire respectively. In this embodiment, the wiring port is connected to a temperature control system. The temperature control system includes a cooling system, a resistance wire heating system and a temperature sensor. The heating system includes a heating wire, a wiring terminal, a wire, a DC switch power supply, a temperature controller and a solid state relay. The temperature controller is connected to the thermocouple and the solid state relay. The thermocouple is in contact with the piezoelectric sample. The DC switch power supply is connected to the heating wire through the wire and the wiring terminal. The heating wire is provided in the stage 6 to realize the temperature rise in the cavity. The cooling system includes a water pump and a water tank connected to the water inlet. A cooling pipe 26 is provided at the water inlet 22, and the water pump is connected to the water tank through the pipe to realize the temperature drop in the cavity.

[0023] In this embodiment, the air extraction port 24 is connected to a pressure control device. The pressure control device includes a vacuum pump and an air pipe. The vacuum pump is connected to the air extraction port 24 through the air pipe to extract the air inside the multi-functional cavity to realize the vacuum of the test environment. In this embodiment, a sample detection system will be used for sample detection. The sample detection system includes an electrical property testing device and an optical monitoring device. The electrical property testing device includes an upper clamp 7 and a lower clamp 8 provided in the multi-functional electrical testing cavity as the upper and lower electrodes. The optical monitoring device includes a silica wafer 3 installed at the opening of the metal upper cover 1 and a laser vibrometer provided outside the multi-functional cavity. The silica wafer 3 and the metal upper cover 1 are hermetically connected. The laser vibrometer monitors the piezoelectric sample 9 inside the multi-functional cavity through the silica wafer 3. There is a circular opening at the top of the metal upper cover for installing the silica wafer 3, and the installation position of the silica wafer is also sealed. The mechanical clamping assembly 30 includes a clamp fixing rod 73 provided on the partition 25, as shown in the appendix Figure 2As shown in the figure, an upper fixture 7 is connected to the fixture fixing rod 73 through a bolt assembly. The clamping end of the upper fixture 7 is a hollow cylinder structure, and the piezoelectric sample is a ring structure, which reduces the contact area and improves the clamping force. A lower fixture 8 for placing the sample is installed on the alumina ceramic upper cover 5; a clamping force adjusting assembly 31 is installed on the upper fixture 7. The clamping force adjusting assembly 31 includes a fixing column 70 inserted into the upper fixture 7. An adjusting nut 72 is screwed on the upper end of the fixing column 70. A spring 71 is clamped between the upper fixture 7 and the lower part of the fixing column 70. When the clamping force adjusting assembly is in use, by rotating the adjusting nut, the fixing column generates vertical displacement, so that the distance between the end of the fixing column and the upper fixture is different, thus generating different weights, and the clamping force of the upper fixture on the piezoelectric sample is different, and then the clamping force of the clamping end of the upper fixture on the sample is adjusted.

[0024] An alumina screw 74 is inserted through the upper end of the fixture fixing rod 73. Insulators 75 are sleeved on the alumina screw 74 and are arranged on both the upper and lower sides of the upper fixture 7. An alumina nut 76 is provided at the upper end of the alumina screw 74. The fixture fixing rod and the upper fixture are connected by combined placement. When dealing with piezoelectric samples of different thicknesses, the height of the upper fixture can be adjusted by replacing different insulators, which is flexible and convenient to use.

[0025] The working principle of the present invention: Place the sample to be tested in the lower fixture on the upper part of the alumina ceramic upper cover. The end of the upper fixture presses on the sample. The clamping force of the upper fixture on the sample can be adjusted through the clamping force adjusting assembly. Turn on the signal generator, and after passing through the high-voltage amplifier, transmit voltage to the upper fixture 7 and the lower fixture 8, and transfer it to the upper and lower surfaces of the piezoelectric sample 9. Use a laser vibrometer to monitor the vibration change of the piezoelectric sample 9 through the silica wafer 3; The stage has a heating wire inside, and heating is realized by the heating of the heating wire. The sample stage is arranged on the partition board. The lower part of the partition board allows the cooling liquid to enter and exit through the water inlets and outlets on both sides of the metal cavity, so as to realize the cooling of the cavity and quickly change the temperature environment in the cavity, improving the detection efficiency; The air extraction port measured through the metal cavity can evacuate the metal cavity into a vacuum environment. At high temperatures, oxidation is likely to occur between the metal cavity and the fixture. To eliminate the interference of this factor, the metal cavity is evacuated into a vacuum environment; The present invention can change the clamping force on the sample, the temperature around the sample, and the air pressure environment in the cavity, realizing the need for testing the electrical properties of piezoelectric ceramics under various simulated test environments, and facilitating a better judgment of the stability and applicable range of piezoelectric ceramics.

Claims

1. A multifunctional piezoelectric ceramic electrical property test cavity, comprising a metal upper cover (1) and a metal cavity (2), characterized in that: Inside the bottom of the metal cavity (2), there is a sample stage composed of an upper cover (5) and a carrier stage (6); a heating wire is built in the carrier stage (6); a mechanical clamping assembly (30) for fixing the sample is provided at the inner bottom of the metal cavity (2); an air extraction port (24), a water inlet (22), a water outlet (23) and a wiring port are provided on the circumferential side surface of the metal cavity (2); a silica wafer (3) is provided at the top end of the metal upper cover (1); the wiring ports are electrically connected to the mechanical clamping assembly (30) and the heating wire respectively.

2. The multifunctional piezoelectric ceramic electrical property testing cavity according to claim 1, wherein: The upper end of the metal cavity (2) is connected to the metal upper cover (1) through a threaded structure, and a rubber gasket (4) is provided at the upper end of the metal cavity (2).

3. The multifunctional piezoelectric ceramic electrical property test cavity according to claim 1, characterized in that: The mechanical clamping assembly (30) includes a clamp fixing rod (73) arranged on a partition board (25), an upper clamp (7) is connected to the clamp fixing rod (73) through a bolt assembly, and a lower clamp (8) for placing the sample is provided on the upper cover (5); a clamping force adjusting assembly (31) is provided on the upper clamp (7), and the upper clamp (7) and the lower clamp (8) are connected to the wiring port through wires.

4. The multifunctional piezoelectric ceramic electrical property testing cavity according to claim 3, wherein: An alumina screw (74) is provided at the upper end of the clamp fixing rod (73), insulators (75) arranged on the upper and lower sides of the upper clamp (7) are sleeved on the alumina screw (74), and an alumina nut (76) is provided at the upper end of the alumina screw (74).

5. The multifunctional piezoelectric ceramic electrical property testing cavity according to claim 3, wherein: The clamping force adjusting assembly (31) includes a fixing column (70) passing through the upper clamp (7), an adjusting nut (72) is provided at the upper end of the fixing column (70), and a spring (71) is provided between the upper clamp (7) and the lower part of the fixing column (70).

6. The multifunctional piezoelectric ceramic electrical property testing cavity according to claim 1, characterized in that: The metal upper cover (1) is a metal upper cover (1) with an attached annular handle.

7. The multi-functional piezoelectric ceramic electrical property test cavity according to claim 3, wherein: The wiring port includes a wire passing port (21) arranged on the side of the metal cavity (2), a wiring terminal (20) arranged in the wire passing port (21), and the wiring terminal (20) is electrically connected to the upper clamp (7), the lower clamp (8) and the heating wire respectively.

8. The multifunctional piezoelectric ceramic electrical property test cavity according to claim 1, characterized in that: A partition board (25) is provided inside the metal cavity (2), the air extraction port (24) is arranged above the partition board (25), and the water inlet (22) and the water outlet (23) are located below the partition board (25).

9. The multifunctional piezoelectric ceramic electrical property test cavity according to claim 1, characterized in that: Both the upper cover (5) and the carrier stage (6) are made of alumina ceramic material.

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