Magnesium oxide-based ceramic wafer dielectric strength measuring system, measuring clamp and application

Abstract

The invention discloses a magnesium oxide-based ceramic chip dielectric strength measuring system, a measuring clamp and application, a base and an end disc in the clamp are respectively connected through a fixed rod, and a sliding assembly sleeves the fixed rod; the first electrode contact and the second electrode contact are fixed on the end face of one side of the base away from the end disc; the first conductive needle is fixed on the end disc and penetrates through the end disc; one end of the first hollow lead tube penetrates through the base and is matched with the first electrode contact, and the other end penetrates through the end disc and is matched with the first conductive needle; the first conductive needle penetrates through the first hollow lead tube through a conductive wire and is connected with the first electrode contact; the second conductive needle is fixed at one end of the sliding assembly away from the base; one end of the second hollow lead tube penetrates through the base and is matched with the second electrode contact, and the other end penetrates through the sliding assembly and is matched with the second conductive needle; the second conductive needle penetrates through the second hollow lead pipe through a conductive wire and is connected with the second electrode connector. The system can measure the electric strength of ceramic chips at different ambient temperatures at normal temperature and high temperature.

Description

Technical Field

[0001] The invention relates to the technical field of measuring the electrical strength of ceramic sheets under high temperature and high pressure, and in particular to a system, a measuring fixture and an application of the electrical strength of magnesium oxide-based ceramic sheets. Background Art

[0002] Magnesium oxide ceramics have good conductivity, mechanical strength and high temperature resistance, with cubic crystal system and NaCl type structure. The melting point of pure magnesium oxide ceramics is 2800℃±13℃, its Mohs hardness is 6, its tensile strength, compressive strength and flexural strength are much lower than those of sintered Al2O3, and its high temperature strength is also low. MgO is a good insulator, with a resistivity of >1014Ω·cm at room temperature, and the resistivity decreases sharply with increasing temperature. Magnesium oxide ceramics are typical alkaline refractory materials, which can work stably up to 2400℃ in an oxidizing atmosphere or under nitrogen protection; MgO will decompose in a reducing atmosphere and volatilize in the form of metallic magnesium, and begin to volatilize in large quantities at 1600℃ in a vacuum; Fe, Zn, Pb, Cu, M and other metals have no reducing effect on it. MgO ceramics can be used as crucibles for smelting metals, and are also suitable for smelting high-purity uranium and thorium in the atomic energy industry. They can also be used as thermocouple protection sleeves, and their ability to allow electromagnetic waves to pass through can be used as radar covers and infrared radiation transmission window materials.

[0003] At present, most magnesium oxide ceramic products are products with low purity or density, and are used in refractory materials, ceramic crucibles, and thermocouple protection tubes. High-purity magnesium oxide ceramics either have high requirements for raw materials, relatively complex processes, and require the use of more organic matter. High-purity magnesium oxide ceramics have the advantages of high temperature resistance and corrosion resistance, but high-purity magnesium oxide ceramics are difficult to sinter densely. Using high-purity lightweight magnesium oxide as raw material, due to its low bulk density and strong reactivity, it is difficult to make powder and shape, especially the preparation of high-density large-size magnesium oxide tubes and crucibles is prone to deformation and cracking.

[0004] The pursuit of electronic materials and devices with high dielectric breakdown strength (DBS) and the elucidation of the high dielectric breakdown mechanism are of great significance for scientific research and industrial applications. Among the numerous material systems, MgO ceramics have great potential due to their simple crystal structure, wide band gap and good physical properties, but their sintering behavior at high temperatures becomes an obstacle to achieving high DBS, and their breakdown mechanism needs to be studied. Summary of the invention

[0005] In view of the above problems, the present invention is proposed to provide a magnesium oxide-based ceramic sheet dielectric strength measurement system, a measurement fixture and an application thereof that overcome the above problems or at least partially solve the above problems.

[0006] In a first aspect, an embodiment of the present invention provides a system for measuring the electrical strength of a magnesium oxide-based ceramic sheet, which may include: a measuring fixture, a high-voltage device, and a tube furnace; wherein the measuring fixture may include: a base, a fixing rod, a sliding assembly, a first electrode connector, a second electrode connector, a first conductive needle, a second conductive needle, a first hollow lead tube, a second hollow lead tube, and an end plate;

[0007] The base and the end plate are connected by the fixing rod, respectively, and the sliding assembly is sleeved on the fixing rod and can slide on the fixing rod; the first electrode connector and the second electrode connector are respectively fixed on the end surface of the base away from the end plate;

[0008] The first conductive needle is fixed on the end plate and passes through the end plate; one end of the first hollow lead tube passes through the base and matches the first electrode connector, and the other end passes through the end plate and matches the first conductive needle; the first conductive needle passes through the first hollow lead tube and is connected to the first electrode connector through a conductive wire;

[0009] The second conductive needle is fixed to one end of the sliding component away from the base; one end of the second hollow lead tube passes through the base to match the second electrode connector, and the other end passes through the sliding component to match the second conductive needle; the second conductive needle passes through the second hollow lead tube through a conductive wire to connect to the second electrode connector;

[0010] The magnesium oxide-based ceramic piece to be measured is clamped between the end plate and the sliding assembly, and is respectively abutted against the first conductive needle and the second conductive needle; the first electrode connector and the second electrode connector are respectively electrically connected to the high-voltage equipment to form a measurement circuit for measuring the magnesium oxide-based ceramic piece to be measured; the measuring fixture clamps the magnesium oxide-based ceramic piece to be measured and places it in the tubular furnace to heat the magnesium oxide-based ceramic piece to be measured through the tubular furnace.

[0011] In one embodiment, the sliding assembly may include: a sliding plate, a support rod and a supporting plate;

[0012] Among them, the sliding plate and the supporting plate are mounted on the fixed rod, and the sliding plate can slide on the fixed rod; one end of the support rod is fixed on the sliding plate, and the other end passes through the supporting plate, and the second conductive needle is fixed on the end of the support rod away from the sliding plate.

[0013] In another embodiment, the support plate is slidable on the fixing rod.

[0014] In another embodiment, the first hollow guide tube and the second hollow guide tube penetrate the sliding plate and the supporting plate respectively.

[0015] In another embodiment, surfaces of the fixing rod, the support rod, the support plate, the first hollow lead tube, the second hollow lead tube and the end plate are coated with a high temperature resistant ceramic coating.

[0016] In another embodiment, the base and the sliding plate are made of metal.

[0017] In another embodiment, the first electrode connector and the second electrode connector are respectively wrapped with insulating ceramics on the outside.

[0018] In another embodiment, the system may further include: a vacuum device, on which are provided two leads connected inside and outside, the tested magnesium oxide-based ceramic sheet is located in the vacuum device and is respectively connected to the first conductive needle and the second conductive needle through the two leads.

[0019] In a second aspect, an embodiment of the present invention provides a measuring fixture, which may include: a base, a fixing rod, a sliding assembly, a first electrode connector, a second electrode connector, a first conductive needle, a second conductive needle, a first hollow lead tube, a second hollow lead tube, and an end plate;

[0020] The base and the end plate are connected by the fixing rods respectively, and the sliding assembly is sleeved on the fixing rods and can slide on the fixing rods; the first electrode connector and the second electrode connector are fixed on the end surface of the base away from the end plate;

[0021] The first conductive needle is fixed on the end plate and passes through the end plate; one end of the first hollow lead tube passes through the base and matches the first electrode connector, and the other end passes through the end plate and matches the first conductive needle; the first conductive needle passes through the first hollow lead tube and is connected to the first electrode connector through a conductive wire;

[0022] The second conductive needle is fixed to one end of the sliding component away from the base; one end of the second hollow lead tube passes through the base to match the second electrode connector, and the other end passes through the sliding component to match the second conductive needle; the second conductive needle passes through the second hollow lead tube through a conductive wire to connect to the second electrode connector;

[0023] The magnesium oxide-based ceramic piece to be measured is clamped between the end plate and the sliding assembly, and is respectively abutted against the first conductive needle and the second conductive needle; the first electrode connector and the second electrode connector are respectively externally connected to high-voltage equipment to form a measurement circuit for measuring the magnesium oxide-based ceramic piece to be measured; the measuring fixture clamps the magnesium oxide-based ceramic piece to be measured for placement in a tubular furnace to heat the magnesium oxide-based ceramic piece to be measured through the tubular furnace.

[0024] In one embodiment, the sliding assembly may include: a sliding plate, a support rod and a supporting plate;

[0025] Among them, the sliding plate and the supporting plate are mounted on the fixed rod, and the sliding plate can slide on the fixed rod; one end of the support rod is fixed on the sliding plate, and the other end passes through the supporting plate, and the second conductive needle is fixed on the end of the support rod away from the sliding plate.

[0026] In another embodiment, the support plate is slidable on the fixing rod.

[0027] In another embodiment, the first hollow guide tube and the second hollow guide tube penetrate the sliding plate and the supporting plate respectively.

[0028] In another embodiment, surfaces of the fixing rod, the support rod, the support plate, the first hollow lead tube, the second hollow lead tube and the end plate are coated with a high temperature resistant ceramic coating.

[0029] In another embodiment, the base and the sliding plate are made of metal.

[0030] In another embodiment, the first electrode connector and the second electrode connector are respectively wrapped with insulating ceramics on their outer sides.

[0031] In a third aspect, an embodiment of the present invention provides an application of the measuring fixture described in the second aspect in a system for measuring the electrical strength of a magnesium oxide-based ceramic sheet.

[0032] The beneficial effects of the above technical solution provided in the embodiments of the present invention include at least:

[0033] The embodiment of the present invention provides a system, a measuring fixture and an application for measuring the dielectric strength of a magnesium oxide-based ceramic sheet. In the system, the ceramic sheet is fixed by a measuring fixture, and the electrode connector (positive and negative electrode interface) at one end of the measuring fixture is connected to a high-voltage device. The measuring fixture clamps the magnesium oxide-based ceramic sheet to be tested and puts it into a tubular furnace, and then manually adjusts the high-voltage device to change the voltage at both ends of the ceramic sheet and the current passing through the ceramic sheet. At the same time, by adjusting the temperature of the tubular furnace, the ambient temperature of the measuring fixture placed therein can be regulated to measure the dielectric strength of the ceramic sheet under high temperature and high pressure. The system provided in the embodiment of the present invention does not have high requirements on the specifications of the ceramic sheet, has a large scale range, and can measure the dielectric strength of the ceramic sheet at different ambient temperatures at normal temperature and high temperature through regulation. The system is easy to operate and safe to operate.

[0034] The above-mentioned magnesium oxide-based ceramic sheet electrical strength measurement system provided in the embodiment of the present invention can measure the breakdown voltage of pure magnesium oxide-based ceramic sheets at different temperatures, especially at high temperatures. The test results can provide key test process parameters such as high-voltage cables for reference, which is more in line with the actual needs of ceramic applications. The test device has a simple structure and convenient testing. In addition, during the test, by adjusting the jaws of the measuring fixture, it can adapt to ceramic sheets of different sizes. On the one hand, it is convenient to place and remove samples such as ceramic sheets before and after the test, and the operation is convenient; on the other hand, it can maintain the relative stability of the positions of the first conductive needle and the second conductive needle during the test, thereby improving the stability and safety of the test.

[0035] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0036] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0038] Figure 1 A framework diagram of a system for measuring the electrical strength of a magnesium oxide-based ceramic sheet provided in an embodiment of the present invention;

[0039] Figure 2 This is one of the structural diagrams of the measuring fixture provided in an embodiment of the present invention;

[0040] Figure 3 This is a second structural diagram of the measuring fixture provided in an embodiment of the present invention;

[0041] Figure 4 A diagram of measurement results provided in an embodiment of the present invention;

[0042] 1- measuring fixture; 2- high-voltage equipment; 3- tube furnace; 4- vacuum equipment; 5- magnesium oxide-based ceramic piece to be measured;

[0043] 101-base; 102-fixing rod; 103-sliding assembly; 104-first electrode connector; 105-second electrode connector; 106-first conductive needle; 107-second conductive needle; 108-first hollow lead tube; 109-second hollow lead tube; 110-end plate; 111-insulating ceramic;

[0044] 1031-sliding plate; 1032-support rod; 1033-support plate. DETAILED DESCRIPTION

[0045] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0046] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", "far", "near", "front", "back" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Embodiment 1

[0049] The present invention provides a magnesium oxide-based ceramic sheet dielectric strength measurement system, referring to Figure 1 to Figure 3As shown, the system may include: a measuring fixture 1, a high-voltage device 2 and a tube furnace 3; wherein the measuring fixture 1 may include: a base 101, a fixed rod 102, a sliding assembly 103, a first electrode connector 104, a second electrode connector 105, a first conductive needle 106, a second conductive needle 107, a first hollow lead tube 108, a second hollow lead tube 109 and an end plate 110; the base 101 and the end plate 110 are respectively connected by the fixed rod 102, and the sliding assembly 103 is sleeved on the fixed rod 102 and can slide on the fixed rod 102; the first electrode connector 104 and the second electrode connector 105 are respectively fixed on the end surface of the base 101 away from the end plate 110; the first conductive needle 106 is fixed on the end plate 110 and penetrates the end plate 110; one end of the first hollow lead tube 108 penetrates the base 101 and matches the first electrode connector 104, and the other end penetrates the end plate 110 and matches the first conductive needle 106; the first conductive The needle 106 passes through the first hollow lead tube 108 through a conductive wire and is connected to the first electrode connector 104; the second conductive needle 107 is fixed to the end of the sliding component 103 away from the base 101; one end of the second hollow lead tube 109 passes through the base 101 and matches the second electrode connector 105, and the other end passes through the sliding component 103 and matches the second conductive needle 107; the second conductive needle 107 passes through the second hollow lead tube 109 through a conductive wire and is connected to the second electrode connector 105; the measured magnesium oxide-based ceramic sheet 5 is clamped between the end plate 110 and the sliding component 103, and is respectively abutted against the first conductive needle 106 and the second conductive needle 107; the first electrode connector 104 and the second electrode connector 105 are respectively electrically connected to the high-voltage equipment 2 to form a measurement circuit for measuring the measured magnesium oxide-based ceramic sheet 5; the measuring fixture 1 clamps the measured magnesium oxide-based ceramic sheet 5 and places it in the tubular furnace 3 to heat the measured magnesium oxide-based ceramic sheet 5 through the tubular furnace 3.

[0050] It should be noted that the measured magnesium oxide-based ceramic sheet in the embodiment of the present invention is a ceramic sheet of a certain size obtained by ball milling, drying, granulation, tableting, sintering and other processes. The diameter of the above-mentioned ceramic sheet in the embodiment of the present invention is 6mm to 60mm, and the thickness is not higher than 40mm, so that the tested ceramic sheet can be adapted to the measuring fixture in this embodiment. Silver paste is applied to the above-mentioned ceramic sheet during measurement so that the current can pass smoothly. It should also be noted that the adjustment temperature of the above-mentioned tube furnace in this embodiment is 25℃~800℃, the furnace mouth diameter of the tube furnace is 150mm, and the base size in this embodiment matches the above-mentioned furnace mouth. It should be further noted that when the tube furnace in this embodiment is in use, the furnace mouth section is open, and the other end is closed by an insulation pad to maintain the internal temperature. The real-time monitoring of the tube furnace thermocouple can directly test the display temperature, and the tester can record the test temperature conditions. The above-mentioned high-voltage equipment in this embodiment is composed of an indicating instrument, a main control circuit, a time control circuit, a high-voltage transformer, etc.

[0051] In the above-mentioned magnesium oxide-based ceramic sheet dielectric strength measurement system provided in the embodiment of the present invention, the ceramic sheet is fixed by a measuring fixture, and the electrode connector (positive and negative electrode interface) at one end of the measuring fixture is connected to the high-voltage equipment. The measuring fixture clamps the magnesium oxide-based ceramic sheet to be tested and puts it into a tubular furnace, and then manually adjusts the high-voltage equipment to change the voltage at both ends of the ceramic sheet and the current passing through the ceramic sheet. At the same time, by adjusting the temperature of the tubular furnace, the ambient temperature of the measuring fixture placed therein can be regulated to measure the dielectric strength of the ceramic sheet under high temperature and high pressure. The system provided in the embodiment of the present invention does not have high requirements on the specifications of the ceramic sheet, has a large scale range, and through regulation, it can measure the dielectric strength of ceramic sheets at different ambient temperatures at normal temperature and high temperature. The system is easy to operate and safe to operate.

[0052] The measurement process of the above system in the embodiment of the present invention is as follows: slide the vertical support rod to a suitable position, and then fix the ceramic sheet coated with silver electrodes at the mouth of the fixture. Then fix the fixture to the mouth of the tube furnace, adjust the ambient temperature, turn on the special high-voltage equipment to adjust the voltage across the sample to be tested, and record the voltage across the ceramic sample in real time. The test results are as follows: Figure 4 And Table 1 is as follows:

[0053] Table 1 Sample voltage test results at different temperatures

[0054]

[0055] from Figure 4 As can be seen from Table 1, the breakdown voltage of the ceramic sheet decreases to a certain extent as the test temperature increases. The higher the temperature, the lower the breakdown voltage test result. However, the breakdown voltage test result has a good linear relationship with the temperature. At the same time, the process type and thickness of the ceramic sheet will also greatly affect the breakdown voltage test value. It is necessary to monitor different breakdown voltage test results according to the temperature parameters actually used in the production line. The system can effectively test the breakdown voltage of different types of ceramic sheets at different temperatures, and can guide the reasonable setting of process parameters in actual production-related processes. Figure 4 Sample 3 was broken down at 600°C and the voltage value could not be measured.

[0056] In this system, the fixture uses an insulating voltage-resistant joint to ensure that there is no external current connection during the breakdown voltage test. It can also ensure that the wires connected to the test ceramic piece during the breakdown voltage test can be effectively insulated and looped back to the high-voltage insulation test equipment. There is no current shunt. A controllable voltage is added to both ends of the ceramic piece. The tubular furnace adjusts the temperature in the furnace to place the ceramic piece to be tested at different ambient temperatures. The electrical breakdown resistance of the pure magnesium oxide-based ceramic piece under high temperature and high pressure has been tested. At the same time, the flatness of the pure magnesium oxide-based ceramic piece to be tested is ensured to ensure the accuracy of the test results. The display temperature can be directly tested through real-time monitoring of the tubular furnace thermocouple, and the tester can record the test temperature conditions.

[0057] Furthermore, the above-mentioned magnesium oxide-based ceramic sheet electrical strength measurement system provided in the embodiment of the present invention can measure the breakdown voltage of pure magnesium oxide-based ceramic sheets at different temperatures, especially at high temperatures. The test results can provide key test process parameters such as high-voltage cables for reference, which is more in line with the actual needs of ceramic applications. The test device has a simple structure and convenient testing. In addition, during the test, by adjusting the jaws of the measuring fixture, it can adapt to ceramic sheets of different sizes. On the one hand, it is convenient to place and remove samples such as ceramic sheets before and after the test, and the operation is convenient; on the other hand, it can maintain the relative stability of the positions of the first conductive needle and the second conductive needle during the test, thereby improving the stability and safety of the test.

[0058] In one embodiment, referring to Figure 2 and Figure 3 As shown, the sliding assembly 103 may include: a sliding plate 1031, a support rod 1032 and a support plate 1033; wherein the sliding plate 1031 and the support plate 1033 are sleeved on the fixed rod 102, and the sliding plate 1031 can slide on the fixed rod 102; one end of the support rod 1032 is fixed on the sliding plate 1031, and the other end passes through the support plate 1033, and the second conductive needle 107 is fixed on the end of the support rod 1032 away from the sliding plate 1031. The above sliding assembly in this embodiment can facilitate the operator to adjust the distance of the clamp jaws, and can adapt to the measured magnesium oxide-based ceramic sheets of multiple sizes.

[0059] In another embodiment, referring to Figure 2 and Figure 3 As shown, the support plate 1033 can slide on the fixing rod 102. In this embodiment, the support plate can also adjust its position, so that it is convenient to clamp a larger size of the magnesium oxide-based ceramic piece to be measured.

[0060] In another embodiment, referring to Figure 2 and Figure 3As shown, the first hollow lead tube 108 and the second hollow lead tube 109 respectively penetrate the slide plate 1031 and the support plate 1033. In this embodiment, the first hollow lead tube and the second hollow lead tube penetrate the slide plate and the support plate, which saves the space of the entire measuring fixture and is easy to put into the tube furnace.

[0061] In another embodiment, referring to Figure 2 and Figure 3 As shown, the surfaces of the fixing rod 102, the support rod 1032, the support plate 1033, the first hollow lead tube 108, the second hollow lead tube 109 and the end plate 110 are coated with a high temperature resistant ceramic coating. In this embodiment, the high temperature resistant ceramic coating is coated on the above components to protect the above components from high temperatures, thereby improving the service life of the entire measuring fixture.

[0062] In another embodiment, referring to Figure 2 and Figure 3 As shown, the base 101 and the sliding plate 1031 are made of metal. In this embodiment, the base and the sliding plate are made of metal to facilitate heat dissipation, so as to increase the service life of the entire measuring fixture.

[0063] In another embodiment, referring to Figure 2 and Figure 3 As shown, the first electrode connector 104 and the second electrode connector 105 are respectively wrapped with insulating ceramics 111. In this embodiment, the insulating ceramics can protect the power supply device and prevent operators from getting electric shock.

[0064] In another embodiment, referring to Figure 1 As shown, the system may further include: a vacuum device 4, on which two leads are provided for connecting the inside and the outside, and the magnesium oxide-based ceramic sheet 5 to be tested is located in the vacuum device 4, and is connected to the first conductive needle 106 and the second conductive needle 107 respectively through the two leads. In this embodiment, the vacuum device can prevent the magnesium oxide-based ceramic sheet to be tested from breaking through the air to form an ionosphere during measurement, thereby causing an adverse effect on the measurement process.

[0065] Embodiment 2

[0066] In the second embodiment of the present invention, a measuring fixture is provided. Figure 2 and Figure 3As shown, the measuring fixture 1 may include: a base 101, a fixed rod 102, a sliding component 103, a first electrode connector 104, a second electrode connector 105, a first conductive needle 106, a second conductive needle 107, a first hollow lead tube 108, a second hollow lead tube 109 and an end plate 110; the base 101 and the end plate 110 are respectively connected through the fixed rod 102, the sliding component 103 is sleeved on the fixed rod 102, and can slide on the fixed rod 102; the first electrode connector 104 and the second electrode connector 105 are respectively fixed on the end surface of the base 101 away from the end plate 110; the first conductive needle 106 is fixed on the end plate 110 and penetrates the end plate 110; one end of the first hollow lead tube 108 penetrates the base 101 and matches the first electrode connector 104, and the other end penetrates the end plate 110 and matches the first conductive needle 106; the first conductive needle 106 penetrates the first hollow lead tube 108 through a conductive wire The hollow lead tube 108 is connected to the first electrode connector 104; the second conductive needle 107 is fixed to one end of the sliding component 103 away from the base 101; one end of the second hollow lead tube 109 passes through the base 101 and matches the second electrode connector 105, and the other end passes through the sliding component 103 and matches the second conductive needle 107; the second conductive needle 107 passes through the second hollow lead tube 109 through a conductive wire and is connected to the second electrode connector 105; the measured magnesium oxide-based ceramic sheet 5 is clamped between the end plate 110 and the sliding component 103, and is respectively abutted against the first conductive needle 106 and the second conductive needle 107; the first electrode connector 104 and the second electrode connector 105 are respectively connected to the high-voltage device 2 to form a measurement circuit for measuring the measured magnesium oxide-based ceramic sheet 5; the measuring fixture 1 clamps the measured magnesium oxide-based ceramic sheet 5 for being placed in the tubular furnace 3 to heat the measured magnesium oxide-based ceramic sheet 5 through the tubular furnace 3.

[0067] The above-mentioned measuring fixture provided in the embodiment of the present invention can measure the breakdown voltage of pure magnesium oxide-based ceramic sheets at different temperatures, especially at high temperatures. The test results can provide key test process parameters such as high-voltage cables for reference, which is more in line with the actual needs of ceramic applications. The test device has a simple structure and convenient testing. In addition, during the test, by adjusting the jaws of the measuring fixture, it can adapt to ceramic sheets of different sizes. On the one hand, it is convenient to place and remove samples such as ceramic sheets before and after the test, and the operation is convenient; on the other hand, it can maintain the relative stability of the positions of the first conductive needle and the second conductive needle during the test, thereby improving the stability and safety of the test.

[0068] In one embodiment, referring to Figure 2 and Figure 3As shown, the sliding assembly 103 may include: a sliding plate 1031, a support rod 1032 and a support plate 1033; wherein the sliding plate 1031 and the support plate 1033 are sleeved on the fixed rod 102, and the sliding plate 1031 can slide on the fixed rod 102; one end of the support rod 1032 is fixed on the sliding plate 1031, and the other end passes through the support plate 1033, and the second conductive needle 107 is fixed on the end of the support rod 1032 away from the sliding plate 1031. The above sliding assembly in this embodiment can facilitate the operator to adjust the distance of the clamp jaws, and can adapt to the measured magnesium oxide-based ceramic sheets of multiple sizes.

[0069] In another embodiment, referring to Figure 2 and Figure 3 As shown, the support plate 1033 can slide on the fixing rod 102. In this embodiment, the support plate can also adjust its position, so that it is convenient to clamp a larger size of the magnesium oxide-based ceramic piece to be measured.

[0070] In another embodiment, referring to Figure 2 and Figure 3 As shown, the first hollow lead tube 108 and the second hollow lead tube 109 respectively penetrate the slide plate 1031 and the support plate 1033. In this embodiment, the first hollow lead tube and the second hollow lead tube penetrate the slide plate and the support plate, which saves the space of the entire measuring fixture and is easy to put into the tube furnace.

[0071] In another embodiment, referring to Figure 2 and Figure 3 As shown, the surfaces of the fixing rod 102, the support rod 1032, the support plate 1033, the first hollow lead tube 108, the second hollow lead tube 109 and the end plate 110 are coated with a high temperature resistant ceramic coating. In this embodiment, the high temperature resistant ceramic coating is coated on the above components to protect the above components from high temperatures, thereby improving the service life of the entire measuring fixture.

[0072] In another embodiment, referring to Figure 2 and Figure 3 As shown, the base 101 and the sliding plate 1031 are made of metal. In this embodiment, the base and the sliding plate are made of metal to facilitate heat dissipation, so as to increase the service life of the entire measuring fixture.

[0073] In another embodiment, referring to Figure 2 and Figure 3 As shown, the first electrode connector 104 and the second electrode connector 105 are respectively wrapped with insulating ceramics 111. In this embodiment, the insulating ceramics can protect the power supply device and prevent operators from getting electric shock.

[0074] In another embodiment, referring to Figure 1As shown, the system may further include: a vacuum device 4, on which two leads are provided for connecting the inside and the outside, and the magnesium oxide-based ceramic sheet 5 to be tested is located in the vacuum device 4, and is connected to the first conductive needle 106 and the second conductive needle 107 respectively through the two leads. In this embodiment, the vacuum device can prevent the magnesium oxide-based ceramic sheet to be tested from breaking through the air to form an ionosphere during measurement, thereby causing an adverse effect on the measurement process.

[0075] Based on the same inventive concept, an embodiment of the present invention further provides an application of the above-mentioned measuring fixture in a system for measuring the electrical strength of a magnesium oxide-based ceramic sheet.

[0076] The specific implementation and beneficial effects of the above-mentioned measuring fixture and the application of the measuring fixture provided in the embodiments of the present invention can refer to the relevant description of the above-mentioned magnesium oxide-based ceramic sheet electrical strength measurement system, and the embodiments of the present invention will not be repeated here.

[0077] Obviously, various changes and modifications may be made to the present invention by those skilled in the art without departing from the spirit and scope of the present invention. The present disclosure is not limited to the precise structure described above and shown in the accompanying drawings, and various changes and modifications may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims. Thus, if these changes and modifications of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes and modifications.

Claims

1. A magnesium oxide-based ceramic sheet dielectric strength measurement system, characterized in that: include: A measuring fixture, a high-voltage device and a tube furnace; wherein the measuring fixture comprises: a base, a fixing rod, a sliding assembly, a first electrode joint, a second electrode joint, a first conductive needle, a second conductive needle, a first hollow lead tube, a second hollow lead tube and an end plate; The base and the end plate are connected by the fixing rod, respectively, and the sliding assembly is sleeved on the fixing rod and can slide on the fixing rod; the first electrode connector and the second electrode connector are respectively fixed on the end surface of the base away from the end plate; The first conductive needle is fixed on the end plate and passes through the end plate; one end of the first hollow lead tube passes through the base and matches the first electrode connector, and the other end passes through the end plate and matches the first conductive needle; the first conductive needle passes through the first hollow lead tube and is connected to the first electrode connector through a conductive wire; The second conductive needle is fixed to one end of the sliding component away from the base; one end of the second hollow lead tube passes through the base to match the second electrode connector, and the other end passes through the sliding component to match the second conductive needle; the second conductive needle passes through the second hollow lead tube through a conductive wire to connect to the second electrode connector; The magnesium oxide-based ceramic piece to be measured is clamped between the end plate and the sliding assembly, and is respectively abutted against the first conductive needle and the second conductive needle; the first electrode connector and the second electrode connector are respectively electrically connected to the high-voltage equipment to form a measurement circuit for measuring the magnesium oxide-based ceramic piece to be measured; the measuring fixture clamps the magnesium oxide-based ceramic piece to be measured and places it in the tubular furnace to heat the magnesium oxide-based ceramic piece to be measured through the tubular furnace.

2. The system according to claim 1, characterized in that The sliding assembly comprises: a sliding plate, a support rod and a supporting plate; Among them, the sliding plate and the supporting plate are mounted on the fixed rod, and the sliding plate can slide on the fixed rod; one end of the support rod is fixed on the sliding plate, and the other end passes through the supporting plate, and the second conductive needle is fixed on the end of the support rod away from the sliding plate.

3. The system according to claim 2, characterized in that The support plate can slide on the fixing rod.

4. The system according to claim 2, characterized in that The first hollow guide tube and the second hollow guide tube penetrate the sliding plate and the supporting plate respectively.

5. The system according to any one of claims 2 to 4, characterized in that: The surfaces of the fixing rod, the support rod, the supporting plate, the first hollow lead tube, the second hollow lead tube and the end plate are coated with a high temperature resistant ceramic coating.

6. The system according to any one of claims 2 to 4, characterized in that: The base and the sliding plate are made of metal.

7. The system according to any one of claims 1 to 4, characterized in that: The first electrode connector and the second electrode connector are respectively wrapped with insulating ceramics on the outside.

8. The system according to any one of claims 1 to 4, characterized in that: The system further includes: a vacuum device, on which two leads for internal and external communication are arranged, the tested magnesium oxide-based ceramic sheet is located in the vacuum device and is connected to the first conductive needle and the second conductive needle respectively through the two leads.

9. A measuring fixture, characterized in that: include: A base, a fixing rod, a sliding assembly, a first electrode connector, a second electrode connector, a first conductive needle, a second conductive needle, a first hollow lead tube, a second hollow lead tube and an end plate; The base and the end plate are connected via the fixing rods respectively, and the sliding assembly is sleeved on the fixing rods and can slide on the fixing rods; The first electrode connector and the second electrode connector are fixed on an end surface of the base away from the end plate; The first conductive needle is fixed on the end plate and passes through the end plate; one end of the first hollow lead tube passes through the base and matches the first electrode connector, and the other end passes through the end plate and matches the first conductive needle; the first conductive needle passes through the first hollow lead tube and is connected to the first electrode connector through a conductive wire; The second conductive needle is fixed to one end of the sliding component away from the base; one end of the second hollow lead tube passes through the base to match the second electrode connector, and the other end passes through the sliding component to match the second conductive needle; the second conductive needle passes through the second hollow lead tube through a conductive wire to connect to the second electrode connector; The magnesium oxide-based ceramic piece to be measured is clamped between the end plate and the sliding assembly, and is respectively abutted against the first conductive needle and the second conductive needle; the first electrode connector and the second electrode connector are respectively externally connected to high-voltage equipment to form a measurement circuit for measuring the magnesium oxide-based ceramic piece to be measured; the measuring fixture clamps the magnesium oxide-based ceramic piece to be measured for placement in a tubular furnace to heat the magnesium oxide-based ceramic piece to be measured through the tubular furnace.

10. The measuring fixture according to claim 9, characterized in that: The sliding assembly comprises: a sliding plate, a support rod and a supporting plate; Among them, the sliding plate and the supporting plate are mounted on the fixed rod, and the sliding plate can slide on the fixed rod; one end of the support rod is fixed on the sliding plate, and the other end passes through the supporting plate, and the second conductive needle is fixed on the end of the support rod away from the sliding plate.

11. The system according to claim 2, characterized in that The support plate can slide on the fixed rod; the first hollow lead tube and the second hollow lead tube pass through the sliding plate and the support plate respectively; the surfaces of the fixed rod, the support rod, the support plate, the first hollow lead tube, the second hollow lead tube and the end plate are coated with a high-temperature resistant ceramic coating; the base and the sliding plate are made of metal; the outer sides of the first electrode connector and the second electrode connector are respectively wrapped with insulating ceramics.

12. Use of the measuring fixture according to any one of claims 9 to 11 in a system for measuring the electrical strength of magnesium oxide-based ceramic sheets.

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