SiC semiconductor ignition material and method for manufacturing the same

Abstract

The application relates to the technical field of aviation engine ignition material preparation, in particular to a SiC semiconductor ignition material and a preparation method thereof, which comprises the following raw material components in percentage by mass: 60-80% of SiC semiconductor composite powder, 0.05-0.35% of isobutylene maleic anhydride copolymer, 0.5-2.5% of dispersant, 0.1-0.5% of defoaming agent, 15.65-39.25% of water and 0.1-1% of pH value regulator; the SiC semiconductor composite powder comprises the following components: 4-8% of Re2Si2O7 powder, 3-6% of SiO2 powder, 1-5% of Y2O3 powder, 1-3% of SrO powder, 40-70% of SiC powder, 15-35% of Al2O3 powder and 5-20% of ZrO2 powder, and the Re is a rare earth element. The ignition material uses rare earth silicate compounds as corrosion-resistant phases and is used in cooperation with other powders, so that the SiC semiconductor ignition material can resist a temperature of 1300 DEG C or above, has excellent high-temperature stability, high-temperature resistance and thermal shock resistance. The problems that the SiC semiconductor ignition material has poor temperature resistance and cannot meet the requirements of an aviation engine ignition system are solved.

Description

Technical Field

[0001] This invention relates to the field of aero-engine ignition material preparation technology, specifically to a SiC semiconductor ignition material and its preparation method. Background Technology

[0002] The engine spark plug is the ignition element of an aero-engine ignition system. It generates an electric spark by breaking down the spark gap with a pulse voltage, which ignites the combustible mixture in the combustion chamber. Electric ignition systems can be classified into inductive discharge and capacitive discharge according to the form of discharge, and into high-voltage inductive / capacitive and low-voltage inductive / capacitive systems according to the output voltage. Systems exceeding 5kV are high-voltage systems, and those below 5kV are low-voltage systems. Capacitive spark discharge has high-frequency oscillation characteristics, producing a very bright spark with a very short duration, and the spark energy is concentrated in a relatively small gas volume. Inductive spark discharge has a wider duration but lower energy; moreover, high-voltage capacitive systems require higher insulation performance from the circuitry, increasing the unreliability of the ignition system. Therefore, to reliably ignite the air-fuel mixture, a low-pressure, high-energy ignition system, namely a semiconductor surface discharge ignition system, is generally used.

[0003] The electrical nozzles used in aero engines mainly include spark nozzles, electro-erosion nozzles, surface nozzles, and semiconductor nozzles. Semiconductor nozzles operating inside engines need to have the following properties: light weight and small size; performance unaffected by air pressure and environmental media; resistance to thermal shock and spark corrosion; good mechanical properties; and stable ignition under applied voltage, with an initial ignition voltage of less than 1000V.

[0004] SiC material itself has stable properties, is resistant to thermal shock and spark corrosion, and has good mechanical properties. It also has a negative temperature coefficient and good thermal conductivity. SiC semiconductor composite ceramics prepared with SiC as the main component have excellent properties such as stable high-temperature performance, low ignition voltage, high spark energy, thermal shock resistance, and thermal corrosion resistance. They can be used as ignition nozzles for aero engines.

[0005] However, with the development of aero engines, combustion chamber temperatures have risen to 1500℃, which places higher demands on the temperature resistance of materials used in engines. The discharge end temperature tolerance of ignition nozzles has also increased from the original 900℃ to the current 1300℃. Under high-temperature conditions, traditional ignition nozzle materials will suffer severe thermal corrosion, oxidation, and deformation, seriously limiting the performance and lifespan of the ignition nozzles.

[0006] Therefore, there is an urgent need for an ignition material that is resistant to high temperatures, electrical corrosion, thermal shock, and has high reliability to meet the demands of increasingly harsh high-temperature working environments. This is not only a key research area in the field of aero-engine ignition system manufacturing technology, but also an important frontier direction in the field of electric ignition systems and related research. Summary of the Invention

[0007] To address the problem that existing SiC semiconductor ignition materials have poor temperature resistance and cannot meet the requirements of aero-engine ignition systems, this invention provides a SiC semiconductor ignition material and its preparation method.

[0008] To achieve the above objectives, the present invention employs the following technical solution:

[0009] This invention provides a SiC semiconductor ignition material, comprising the following raw material components by mass fraction: 60%–80% SiC semiconductor composite powder, 0.05%–0.35% isobutylene-maleic anhydride copolymer, 0.5%–2.5% dispersant, 0.1%–0.5% defoamer, 15.65%–39.25% water, and 0.1%–1% pH adjuster;

[0010] The SiC semiconductor composite powder comprises, by mass fraction: 4%–8% Re2Si2O7 powder, 3%–6% SiO2 powder, 1%–5% Y2O3 powder, 1%–3% SrO powder, 40%–70% SiC powder, 15%–35% Al2O3 powder, and 5%–20% ZrO2 powder, wherein Re is a rare earth element.

[0011] Preferably, the dispersant is an ammonium polyacrylate solution, and the concentration of the ammonium polyacrylate solution is 30 wt% to 50 wt%.

[0012] Preferably, the defoamer is n-octanol.

[0013] Preferably, the pH adjuster is a tetramethylammonium hydroxide solution, and the concentration of the tetramethylammonium hydroxide solution is 8wt% to 12wt%.

[0014] The present invention also provides a method for preparing the SiC semiconductor ignition material as described above, comprising the following steps:

[0015] Preparation of SiC semiconductor composite powder;

[0016] SiC semiconductor composite powder is mixed with isobutylene maleic anhydride copolymer, dispersant, defoamer, water and pH adjuster in a certain proportion and then defoamed under vacuum to obtain a mixed slurry.

[0017] The mixed slurry is poured into a mold, solidified, demolded, and dried to obtain a green body;

[0018] Remove the glue from the green body;

[0019] The debinding green blank is sintered at high temperature to obtain SiC semiconductor ignition material.

[0020] Furthermore, the method for preparing SiC semiconductor composite powder is as follows:

[0021] Re2Si2O7 powder, SiO2 powder, Y2O3 powder, SrO powder, SiC powder, Al2O3 powder and ZrO2 powder are mixed in a certain proportion to obtain a mixed powder.

[0022] The mixed powder was uniformly mixed by wet ball milling to obtain SiC semiconductor composite powder; wherein the grinding ball was agate ball, the medium was anhydrous ethanol, and the volume ratio of agate ball, mixed powder and anhydrous ethanol was 2:1:1.

[0023] Preferably, the vacuum degassing is performed using a vacuum pump, and the degassing time is 30 to 60 minutes.

[0024] Furthermore, after curing and molding, the product is demolded and dried at room temperature for 24–48 hours, and then dried at 60–80°C for another 24–48 hours.

[0025] Furthermore, the method for removing glue from the green body is as follows:

[0026] The green body is heated to 650℃~750℃ at a heating rate of 1℃ / min~2℃ / min and held at that temperature for 2~4 hours to complete the glue removal process.

[0027] Furthermore, the method for obtaining SiC semiconductor ignition material by high-temperature sintering of the debinding green blank is as follows:

[0028] The debonded green preform was embedded in a 1:1 volume ratio of SiC semiconductor composite powder and BN powder, under a vacuum of 3.6 × 10⁻⁶. -3 Under conditions of nitrogen filling pressure of 0.2-0.8 MPa, the temperature is increased to 1600-1800℃ at a heating rate of ≤5℃ / min and held for 1-3 hours to obtain SiC semiconductor ignition material.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] This invention discloses a SiC semiconductor ignition material. The ignition material uses Re2Si2O7 rare earth silicate compound as a corrosion-resistant phase, combined with SiC powder, Al2O3 powder, and ZrO2 powder. SiO2 powder and Y2O3 powder serve as sintering aids, and the addition of SrO improves the material's electrical properties. The rare earth silicate compound exhibits excellent high-temperature stability, and its addition significantly improves the material's high-temperature resistance and thermal shock resistance, enabling the SiC semiconductor ignition material to withstand temperatures exceeding 1300℃. The material also possesses a certain number of spherical closed pores, which greatly enhances its thermal shock resistance, preventing cracking, deformation, or failure after repeated ignitions and extending its service life.

[0031] This invention also provides a method for preparing the SiC semiconductor ignition material as described above. This method involves preparing SiC semiconductor composite powder; mixing the SiC semiconductor composite powder with isobutylene maleic anhydride copolymer, dispersant, defoamer, water, and pH adjuster in a specific ratio; defoaming under vacuum to obtain a mixed slurry; injecting the mixed slurry into a mold, curing, demolding, and drying to obtain a green blank; and removing the binder from the green blank and sintering at high temperature to achieve the preparation of the SiC semiconductor ignition material. The preparation method is simple, the process is simple and controllable, the production cost is low, and continuous production is possible. Furthermore, various complex shapes can be prepared using gel casting molding, providing assurance for handling different working environments. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a method for preparing a SiC semiconductor ignition material according to the present invention.

[0033] Figure 2 This is a macroscopic morphology diagram of a SiC semiconductor ignition material according to the present invention.

[0034] Figure 3 This is a microstructure diagram of a SiC semiconductor ignition material according to the present invention.

[0035] Figure 4 This is an XRD pattern of a SiC semiconductor ignition material according to the present invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0038] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0039] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0040] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0041] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0042] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0043] This invention discloses a SiC semiconductor ignition material, comprising the following raw material components by mass fraction: 60%–80% SiC semiconductor composite powder, 0.05%–0.35% isobutylene-maleic anhydride copolymer, 0.5%–2.5% dispersant, 0.1%–0.5% defoamer, 15.65%–39.25% water, and 0.1%–1% pH adjuster; wherein the dispersant is ammonium polyacrylate solution with a concentration of 30 wt%–50 wt%; the defoamer is n-octanol; and the pH adjuster is tetramethylammonium hydroxide solution with a concentration of 8 wt%–12 wt%.

[0044] The SiC semiconductor composite powder comprises, by mass fraction: 4%–8% Re2Si2O7 powder, 3%–6% SiO2 powder, 1%–5% Y2O3 powder, 1%–3% SrO powder, 40%–70% SiC powder, 15%–35% Al2O3 powder, and 5%–20% ZrO2 powder, wherein Re is a rare earth element, preferably La, Lu, Y, or Yb.

[0045] See Figure 1 The present invention also provides a method for preparing the SiC semiconductor ignition material as described above, comprising the following steps:

[0046] S1: Preparation of SiC semiconductor composite powder, specifically:

[0047] Re2Si2O7 powder, SiO2 powder, Y2O3 powder, SrO powder, SiC powder, Al2O3 powder and ZrO2 powder are mixed in a certain proportion to obtain a mixed powder.

[0048] The mixed powder was uniformly mixed by wet ball milling to obtain SiC semiconductor composite powder; wherein the grinding ball was agate ball, and the medium was anhydrous ethanol, and the volume ratio of agate ball, mixed powder and anhydrous ethanol was 2:1:1.

[0049] S2: SiC semiconductor composite powder is mixed evenly with isobutylene maleic anhydride copolymer, dispersant, defoamer, water and pH adjuster in a certain proportion, and then vacuum defoamed to obtain a mixed slurry, specifically as follows:

[0050] SiC semiconductor composite powder is mixed with isobutylene maleic anhydride copolymer, dispersant, defoamer and water. Then a pH adjuster is added to adjust the pH of the mixture to 9-10. After mixing evenly, the mixture is defoamed by vacuum pump for 30-60 minutes to obtain a mixed slurry.

[0051] S3: Inject the mixed slurry into the mold, allow it to solidify and mold, demold, and dry to obtain the green body, specifically:

[0052] The mixed slurry is injected into a mold, cured and shaped at room temperature, demolded, dried at room temperature for 24–48 hours, and then dried at 60–80°C for 24–48 hours to obtain a green body.

[0053] S4: Remove the glue from the green body, specifically:

[0054] The green body is heated to 650℃~750℃ at a heating rate of 1℃ / min~2℃ / min and held at that temperature for 2~4 hours to complete the glue removal process.

[0055] S5: The green blank after debinding is subjected to high-temperature sintering to obtain SiC semiconductor ignition material, specifically:

[0056] The debonded green preform was embedded in a 1:1 volume ratio of SiC semiconductor composite powder and BN powder, under a vacuum of 3.6 × 10⁻⁶. -3 Under conditions of nitrogen filling pressure of 0.2-0.8 MPa, the temperature is increased to 1600-1800℃ at a heating rate of ≤5℃ / min and held for 1-3 hours to obtain SiC semiconductor ignition material.

[0057] To further illustrate the SiC semiconductor ignition material and its preparation method provided by the present invention, Examples 1-10 are provided, and the preparation process is as follows:

[0058] SiC semiconductor composite powder, isobutylene maleic anhydride copolymer, 0.5%–2.5% dispersant, defoamer, and water were mixed uniformly according to the specified proportions. The concentration of the dispersant, ammonium polyacrylate solution, was 40 wt%. Then, a pH adjuster was added to adjust the pH of the mixture to 10. The concentration of the pH adjuster, tetramethylammonium hydroxide solution, was 10 wt%. The system was mixed uniformly using wet ball milling, stirred, and defoamed under vacuum to obtain a mixed slurry. The mixed slurry was poured into a mold, cured at room temperature, demolded, dried at room temperature, and then dried in a drying oven to obtain a green body. The green body was heated to 700℃ at a rate of 2℃ / min and held for 4 hours to complete the debinding process. The debinded green body was placed in a graphite crucible, embedded in a 1:1 volume ratio of SiC semiconductor composite powder and BN powder, and placed in a vacuum sintering furnace. The vacuum was then reduced to 3.6 × 10⁻⁶. -3 Pa, filled with argon gas, heated, and sintered to obtain SiC semiconductor ignition material. The composition of each material and reaction conditions by mass percentage in Examples 1-10 are shown in the table below:

[0059]

[0060]

[0061]

[0062]

[0063] The properties of the SiC semiconductor ignition materials prepared in Examples 1-10 are shown in the table below:

[0064]

[0065]

[0066] It can be seen that the open porosity of this ignition nozzle is 0.001–0.015, the closed porosity is 0.058–0.105, the flexural strength is 190–320 MPa, and the bulk density is 3.012–3.178 g·cm³. -1 The insulation resistance at room temperature is 31-60kΩ, the ignition voltage is 530-700V, and the insulation resistance at 1300℃ is 25-63kΩ.

[0067] See Figure 2 The image shows the macroscopic morphology of the SiC ignition material prepared in Example 1 after being remelted at 1300℃. It has a diameter of 12.5 mm, a height of 3.0 mm, and a density of 3.08 g / cm³. 3 This SiC ignition material exhibits excellent high-temperature resistance; after being remelted at 1300℃, the material retains its shape and has no surface defects.

[0068] See Figure 3 The image shows a SEM image of the SiC semiconductor ignition material prepared in Example 4. The black irregular particles are SiC grains, the white particles are ZrO2, and the grayish-white particles are rare-earth silicate sintering aids, which effectively bind the SiC grains together to form a dense sintered body. Furthermore, fine Al2O3 grains are embedded in the glassy phase formed by the sintering aids. In addition, the material contains 8%–10% closed pores, which effectively improves the thermal shock resistance of the SiC semiconductor ignition material.

[0069] See Figure 4 The image shows the XRD pattern of the SiC semiconductor ignition material prepared in Example 6. The XRD pattern indicates that the main phases of the SiC semiconductor ignition material prepared by the method of this invention are 6H-SiC, α-Al₂O₃, and ZrO₂, with no other impurity peaks.

[0070] In summary, this invention provides a SiC semiconductor ignition material and its preparation method. This SiC semiconductor ignition material has excellent corrosion resistance, can operate normally at 1300℃ without material shedding, is unaffected by the use of performance materials, and has high thermal shock resistance. It can meet the research needs in the current field of aero-engine ignition system preparation technology and is an advanced technology in the current field of aero-engine ignition system preparation technology.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A SiC semiconductor ignition material, characterized in that, The raw material components, by mass fraction, include: 60%–80% SiC semiconductor composite powder, 0.05%–0.35% isobutylene-maleic anhydride copolymer, 0.5%–2.5% dispersant, 0.1%–0.5% defoamer, 15.65%–39.25% water, and 0.1%–1% pH adjuster; wherein the dispersant is ammonium polyacrylate solution with a concentration of 30 wt%–50 wt%; the defoamer is n-octanol; and the pH adjuster is tetramethylammonium hydroxide solution with a concentration of 8 wt%–12 wt%. The SiC semiconductor composite powder comprises, by mass fraction: 4%–8% Re2Si2O7 powder, 3%–6% SiO2 powder, 1%–5% Y2O3 powder, 1%–3% SrO powder, 40%–70% SiC powder, 15%–35% Al2O3 powder, and 5%–20% ZrO2 powder, wherein Re is a rare earth element.

2. The method for preparing the SiC semiconductor ignition material as described in claim 1, characterized in that, Includes the following steps: Preparation of SiC semiconductor composite powder; SiC semiconductor composite powder is mixed with isobutylene maleic anhydride copolymer, dispersant, defoamer, water and pH adjuster in a certain proportion and then defoamed under vacuum to obtain a mixed slurry. The mixed slurry is poured into a mold, cured and shaped, demolded, and dried to obtain a green body; Remove the glue from the green body; The debinding green blank is sintered at high temperature to obtain SiC semiconductor ignition material.

3. The method for preparing SiC semiconductor ignition material according to claim 2, characterized in that, The method for preparing SiC semiconductor composite powder is as follows: Re2Si2O7 powder, SiO2 powder, Y2O3 powder, SrO powder, SiC powder, Al2O3 powder and ZrO2 powder are mixed in a certain proportion to obtain a mixed powder. The mixed powder was uniformly mixed by wet ball milling to obtain SiC semiconductor composite powder; wherein the grinding ball was agate ball, the medium was anhydrous ethanol, and the volume ratio of agate ball, mixed powder and anhydrous ethanol was 2:1:

1.

4. The method for preparing SiC semiconductor ignition material according to claim 2, characterized in that, The vacuum degassing process uses a vacuum pump for degassing, and the degassing time is 30 to 60 minutes.

5. The method for preparing SiC semiconductor ignition material according to claim 2, characterized in that, After curing and molding, demold and dry at room temperature for 24–48 hours, then dry at 60–80℃ for another 24–48 hours.

6. The method for preparing SiC semiconductor ignition material according to claim 2, characterized in that, The method for removing glue from the green body is as follows: The green body is heated to 650℃~750℃ at a heating rate of 1℃ / min~2℃ / min and held at that temperature for 2~4 hours to complete the glue removal process.

7. The method for preparing SiC semiconductor ignition material according to claim 2, characterized in that, The method for obtaining SiC semiconductor ignition material by high-temperature sintering of the debinding green blank is as follows: The debonded green preform was embedded in a 1:1 volume ratio of SiC semiconductor composite powder and BN powder, under a vacuum of 3.6 × 10⁻⁶. -3 Under conditions of nitrogen filling pressure of 0.2-0.8 MPa, the temperature is increased to 1600-1800℃ at a heating rate of ≤5℃ / min and held for 1-3 hours to obtain SiC semiconductor ignition material.

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