High-thermal-conductivity nitride whisker reinforced nitride ceramic-based composite material and preparation method thereof

Abstract

The invention relates to a high-thermal-conductivity nitride whisker reinforced nitride ceramic-based composite material and a preparation method thereof, and the preparation method comprises the following steps: dissolving a carbon precursor and an aluminum salt in a solvent containing a supporting electrolyte to obtain a carbon precursor / aluminum salt electrolyte; placing a conductive substrate in a carbon precursor / aluminum salt electrolyte, performing electrochemical deposition to obtain an aluminum / carbon precursor substrate, cutting the aluminum / carbon precursor substrate into a frame-type aluminum / carbon precursor growth substrate, transferring the frame-type aluminum / carbon precursor growth substrate into a graphitization furnace, and performing gradient heating carbon thermal reduction nitridation reaction to obtain an aluminum nitride whisker / porous carbon composite frame after the reaction; mixing the nitride particle powder, a sintering aid and a dispersing agent to obtain mixed slurry; and filling the aluminum nitride whisker / porous carbon composite frame with the mixed slurry, carrying out dry-pressing molding to obtain a composite board, and carrying out hot-pressing calcination to obtain the nitride nanofiber toughened nitride ceramic substrate. Accurate regulation and control of the growth process of the aluminum nitride whiskers are achieved, and the problems that the length-diameter ratio of aluminum nitride nanofibers is low, and distribution is uneven are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of ceramic matrix composites, specifically to a high thermal conductivity nitride whisker-reinforced nitride ceramic matrix composite and its preparation method. Background Technology

[0002] With the rapid development of modern microelectronics technology, electronic devices and equipment are gradually moving towards miniaturization and high integration. While this trend brings functional diversity, it also leads to a significant increase in power consumption and heat. Prolonged operation in high-temperature environments can severely impact the stability and safety of electronic devices. Therefore, developing advanced heat dissipation materials has become an important way to promote the rapid development of electronic technology and is also key to solving this problem.

[0003] Aluminum nitride (AlN), as a high-performance advanced ceramic material, has attracted much attention due to its unique physical and chemical properties. Aluminum nitride possesses high thermal conductivity (typically exceeding 200 W / m·K), reliable electrical insulation, low dielectric constant and dielectric loss, and a coefficient of thermal expansion comparable to silicon, making it an ideal choice for next-generation highly integrated semiconductor substrates and electronic device packaging. Furthermore, aluminum nitride exhibits excellent corrosion resistance and thermal stability, maintaining its performance even in extreme environments. However, traditional aluminum nitride ceramic fabrication processes suffer from low thermal conductivity, insufficient densification, and relatively low structural strength, limiting its application in high-power electronic devices.

[0004] In existing technologies, researchers have developed various whisker reinforcement techniques to improve the performance of aluminum nitride ceramic substrates, but all have significant drawbacks. For example, introducing whisker growth sources (such as aluminum salts) and catalysts (such as transition metal compounds) into the latex system can lead to carbon impurities remaining in the organic components of the latex during subsequent sintering, resulting in a decrease in the interfacial bonding between the whiskers and the matrix. Furthermore, the catalyst is difficult to disperse uniformly, easily causing disordered whisker growth and large differences in aspect ratio, making it impossible to form an effective thermal conductivity pathway. Although freeze-drying can preserve the porous structure of the slurry, low-temperature sintering leads to incomplete nitriding reactions, resulting in a large number of unreacted aluminum oxide impurities on the whisker surface, significantly reducing thermal conductivity (<150 W / m·K). At the same time, the whisker growth motive force is insufficient at low temperatures, with aspect ratios generally <30, resulting in limited improvement in the toughness of the composite material (fracture toughness <3 MPa·m). 1 / 2Vacuum impregnation can improve the filling efficiency of whisker precursors, but ice crystal growth during freeze-drying disrupts the continuity of the precursors, leading to uneven whisker distribution. Furthermore, whiskers prepared by this method have low aspect ratios (typically <40), and the vacuum environment easily introduces air bubbles, resulting in high porosity (typically >8%) in the composite material. In-plane thermal conductivity is difficult to exceed 180 W / m·K, and normal thermal conductivity is even lower (<150 W / m·K). In existing mixing processes (such as ball milling and stirring), nanofibers tend to agglomerate and are randomly distributed in the matrix, failing to form a continuous network. During sintering, gaps easily form between fibers and particles, resulting in a density typically <90%, severely impacting mechanical properties (flexural strength <250 MPa). These problems make it difficult for existing aluminum nitride whisker-reinforced ceramic materials to simultaneously meet the requirements of high thermal conductivity, high toughness, and high density, necessitating the development of a novel preparation method to address these deficiencies. Summary of the Invention

[0005] The purpose of this invention is to overcome at least one of the defects in the prior art by providing a high thermal conductivity nitride whisker-reinforced nitride ceramic matrix composite material and its preparation method. This method solves problems such as low thermal conductivity and low fracture toughness caused by low aspect ratio after in-situ whisker growth with the addition of a growth source and catalyst to latex, combined growth of aluminum nitride whiskers via freeze-drying and low-temperature sintering, and combined growth of aluminum nitride whiskers via vacuum impregnation and freeze-drying, as well as low density caused by uneven distribution of aluminum nitride nanofibers in the substrate.

[0006] This invention achieves this through precise control of process parameters at each step. For example, the carbon precursor concentration range is 10-30 wt%. When the carbon precursor concentration is too low (<10 wt%), a continuous carbon framework cannot be formed, resulting in insufficient support for subsequent aluminum nitride whisker growth and a low aspect ratio. When the concentration is too high (>30 wt%), the carbon framework becomes excessively dense, hindering nitrogen atom diffusion, inhibiting whisker growth, increasing residual carbon impurities, and decreasing thermal conductivity. Verification through examples shows that 10-30 wt% is the optimal range. The aluminum salt concentration range is 0.1–2.0 M. When the aluminum salt concentration is <0.1 M, the aluminum source is insufficient, resulting in low whisker yield and uneven dispersion. When the aluminum salt concentration is >2.0 M, aluminum ions easily agglomerate, leading to whisker coarsening and a reduced aspect ratio. A concentration in the 0.1-2.0 M range ensures uniform whisker growth and a better aspect ratio. Simultaneously adjusting process parameters such as laser cutting power, speed, and pulse frequency, as well as the stage division and rate control of gradient heating, enabled precise control of the aluminum nitride whisker growth process, effectively solving problems such as low aspect ratio and uneven distribution of aluminum nitride nanofibers. The resulting high thermal conductivity nitride ceramic whisker-reinforced nitride ceramic matrix composite material exhibits excellent properties, with a flexural strength of 300-500 MPa and a fracture toughness of 4-12 MPa·m. 1 / 2With a porosity as low as 0.1-5%, an in-plane thermal conductivity of 200-260 W / (m·K), and a normal thermal conductivity of 180-280 W / (m·K), the material's overall performance is significantly improved, and it has broad application prospects in fields such as electronic packaging and aerospace.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] One objective of this invention is to provide a method for preparing a high thermal conductivity nitride ceramic whisker-reinforced nitride ceramic matrix composite material, comprising the following steps:

[0009] Step 1: Dissolve the carbon precursor and aluminum salt in a solvent containing a supporting electrolyte to prepare a carbon precursor / aluminum salt electrolyte with excellent conductivity.

[0010] Step 2: Place the conductive substrate in the carbon precursor / aluminum salt electrolyte obtained in Step 1 and perform electrochemical deposition to obtain the aluminum / carbon precursor substrate.

[0011] Step 3: Cut the aluminum / carbon precursor substrate obtained in Step 2 into a frame-type aluminum / carbon precursor growth substrate.

[0012] Step 4: Transfer the framework-type aluminum / carbon precursor growth substrate obtained in Step 3 to a graphitization furnace for gradient heating carbothermic reduction nitridation reaction. Inert gas is continuously introduced during the reaction. After the reaction, aluminum nitride whiskers / porous carbon composite frameworks with uniformly sized and distributed pores are obtained.

[0013] Step 5: Mix the nitride particle powder, sintering aid and dispersant to obtain a mixed slurry;

[0014] Step 6: Fill the mixed slurry obtained in Step 5 into the aluminum nitride whisker / porous carbon composite framework obtained in Step 4, and dry press to form a composite plate;

[0015] Step 7: Hot-press and calcinate the composite plate obtained in Step 6 to obtain a nitride nanofiber toughened nitride ceramic substrate.

[0016] Furthermore, in step one:

[0017] The carbon precursor includes one or more of phenolic resin, glucose, sucrose, acetonitrile, dimethylformamide, graphene oxide, and carbon nanotubes, and the concentration of the carbon precursor in the electrolyte ranges from 10 to 30 wt%.

[0018] The aluminum salt includes one or more of aluminum sulfate, aluminum chloride, aluminum nitrate, aluminum isopropoxide, aluminum silicate, and aluminum sulfide, and the concentration of the aluminum salt in the electrolyte ranges from 0.1 to 2.0 M.

[0019] The supporting electrolyte includes one or more of the following: sulfuric acid, potassium chloride, potassium nitrate, potassium dihydrogen phosphate, tetraethylammonium hexafluorophosphate, tetrabutylammonium hexafluorophosphate, tetramethylammonium chloride, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, sodium hydroxide, lithium chloride, and lithium perchlorate. The concentration of the supporting electrolyte in the electrolyte is in the range of 0.1-1.0 M.

[0020] The solvent includes one or more of deionized water, anhydrous ethanol, acetonitrile, dimethylformamide, dimethyl sulfoxide, acetone, and tetrahydrofuran.

[0021] Further, in step two, the electrochemical deposition specifically involves:

[0022] A three-electrode system is assembled by using a conductive substrate as the working electrode, a platinum sheet or graphite rod as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The three-electrode system is placed in an electrolytic cell, and a prepared aluminum salt / carbon precursor electrolyte is added. Electrochemical deposition is carried out under constant potential / constant current to obtain a tightly bonded aluminum / carbon precursor substrate.

[0023] Further, the conductive substrate includes one or more of copper foil, nickel foil, titanium foil, graphite sheet, carbon cloth, carbon paper, tin oxyfluoride glass, and indium tin oxide glass; the constant potential has a value of -1.0V to -2.0V (vs. Ag / AgCl); and the constant current has a current density of 1–10 mA / cm². 2 The electrochemical deposition time is 10–60 minutes.

[0024] Furthermore, in step three, the cutting is laser cutting.

[0025] The laser cutting process has a laser power of 10-100W, a cutting speed of 10-500mm / s, and a pulse frequency of 1-100kHz.

[0026] The auxiliary gas for the laser cutting process includes one or more of nitrogen and argon, with a pressure of 0.5-2 bar.

[0027] The shape of the frame-type aluminum / carbon precursor growth substrate includes one or more of the following: triangle, quadrilateral, hexagon, circle, quadrilateral with inner diameter triangle, quadrilateral with inner diameter hexagon, circle with inner diameter hexagon, circle with inner diameter quadrilateral, and circle with inner diameter triangle. When the shape of the frame-type aluminum / carbon precursor growth substrate has an inner diameter, the inner diameter ranges from 1 to 3 cm.

[0028] Furthermore, in step four:

[0029] The gradient-heating carbothermal reduction nitriding process consists of three stages. The first stage involves heating from room temperature to 400-600℃ at a rate of 5-10℃ / min, holding for 1-2 hours under an inert atmosphere to remove volatile components and carbonize the carbon precursor to form a carbon framework. The second stage involves heating to 800-1000℃ at a rate of 3-5℃ / min, holding for 1-1.5 hours to nitrid the aluminum source, forming aluminum nitride whiskers. The third stage involves heating to 1400-1600℃ at a rate of 2-3℃ / min, holding for 2-3 hours, and pyrolyzing the carbon framework to form a porous aluminum carbide framework. In other words, the gradient-heating carbothermal reduction nitriding reaction consists of four gradient stages, sequentially achieving the removal of volatile components, carbonization of the carbon precursor to form a carbon framework, nitridation of the aluminum source to form aluminum nitride whiskers, and pyrolysis of the carbon framework to form a porous carbon framework.

[0030] The inert gas includes one or more of nitrogen and argon;

[0031] The aluminum nitride whisker / porous carbon composite framework has a pore size range of 10-500 nm and a specific surface area of ​​100-1000 m². 2 / g, with an inner diameter of 1-3cm;

[0032] Furthermore, in step five:

[0033] The nitride particle powder includes one or more of aluminum nitride, boron nitride, silicon nitride, gallium nitride, and titanium nitride, and the particle size is 0.1μm-1μm;

[0034] The sintering aids include one or more of yttrium oxide, calcium oxide, dysprosium oxide, boron oxide, calcium fluoride, titanium oxide, aluminum oxide, and lithium oxide, accounting for 0.5 to 5 wt% of the nitride particles;

[0035] The dispersant includes one or more of anhydrous ethanol, acetone, dichloromethane, chloroform, xylene, and tetrahydrofuran;

[0036] The solid content of the nitride particles in the nitride whisker / particle mixed slurry is 50-80 wt%, and the viscosity is <300 mPa·s;

[0037] The nitride particulate powder, sintering aid and dispersant are homogenized by gas vortex centrifugation, wherein the gas in the gas vortex centrifugation is one or more of nitrogen and argon, the gas flow rate is 10-20 L / min, the centrifugation speed is 100-2000 rpm, and the homogenization time is 1-5 h.

[0038] Furthermore, in step six, the mixed slurry needs to be sieved before filling, and the sieved mixed slurry is filled by scraping.

[0039] The sieving process uses a 200-500 mesh sieve to remove larger particles and agglomerates from the mixed slurry.

[0040] The scraping speed is 5-15 cm / min, and the angle between the scraper and the surface of the aluminum nitride whisker / porous carbon composite framework is maintained at 30-60°.

[0041] The dry pressing process involves a pressure of 10-50 MPa and a holding time of 5-30 minutes to ensure that the mixed slurry fully fills the pores of the frame and forms the initial shape.

[0042] Furthermore, in step seven:

[0043] The hot-pressing calcination process consists of two stages: the first stage involves heating from room temperature to 400-600℃ at a rate of 5-8℃ / min and holding at that temperature for 1-2 hours in an oxygen atmosphere to remove residual carbon through oxidation; the second stage involves switching to an inert atmosphere and heating to 1600-1900℃ at a rate of 5-10℃ / min, with a hot-pressing pressure of 30-60MPa and a holding time of 1-3 hours. The hot-pressing calcination process is carried out under an inert gas protective atmosphere, with the inert gas being argon or nitrogen at a flow rate of 1-3L / min, to prevent oxidation of the composite board at high temperatures and ensure the final product is a high-performance nitride nanofiber-reinforced nitride ceramic substrate.

[0044] The second objective of this invention is to provide a high thermal conductivity nitride ceramic whisker-reinforced nitride ceramic matrix composite material, which is prepared by the method described above;

[0045] The nitride ceramic matrix composite material has a flexural strength of 300-500 MPa and a fracture toughness of 4-12 MPa·m. 1 / 2 The porosity is 0.1-5%, the in-plane thermal conductivity is 200-260 W / (m·K), and the normal thermal conductivity is 180-280 W / (m·K).

[0046] Compared with the prior art, the present invention has the following advantages:

[0047] (1) This invention achieves atomic-level uniform distribution and interface optimization of aluminum / carbon precursors on a conductive substrate through electrochemical deposition technology, and combined with laser cutting process, realizes high-precision morphology control at the micro-nano scale. The electrochemically deposited aluminum / carbon precursor substrate has excellent conductivity and interfacial bonding force, providing a high-strength growth platform for subsequent reactions.

[0048] (2) This invention employs a multi-stage gradient heating strategy, combining carbothermal reduction and nitriding reactions, to achieve in-situ growth of aluminum nitride whiskers and simultaneous construction of porous carbon frameworks under an inert atmosphere. The combination of aluminum nitride whiskers and porous carbon frameworks enhances the mechanical properties and thermal stability of the composite framework. Simultaneously, the aluminum nitride whiskers grown in situ under the constraint of the porous carbon framework overcome the problems of high randomness and high dispersion of toughening fibers grown in situ in traditional ceramic substrates, and overcome the inevitable fiber breakage and morphology damage during mixing. This achieves a perfect unity of nanoscale dispersion and interface optimization, constructing a ceramic reinforcing phase with highly continuous thermal conductivity pathways.

[0049] (3) This invention employs gas vortex centrifugal homogenization mixing technology to achieve molecular-level uniform dispersion of nitride particles and sintering aids, constructing a composite slurry system with high uniformity and high stability. Compared with traditional ball milling and dry mixing processes. Attached Figure Description

[0050] Figure 1 : Cross-sectional SEM image of the frame-type aluminum nitride whisker / porous carbon framework in Example 1;

[0051] Figure 2 SEM image of the front view of the frame-type aluminum nitride whisker / porous carbon framework in Example 1;

[0052] Figure 3 SEM image of the cross section of the aluminum nitride whisker-reinforced aluminum nitride ceramic matrix composite material in Example 1. Detailed Implementation

[0053] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0054] This invention provides a framework-type nitride ceramic whisker-reinforced nitride ceramic matrix composite material and its preparation method, comprising the following steps:

[0055] (1) The carbon precursor and aluminum salt are dissolved in a solvent containing a supporting electrolyte to prepare a carbon precursor / aluminum salt electrolyte with excellent conductivity.

[0056] (2) A three-electrode system is assembled using a conductive substrate as the working electrode, a platinum sheet or graphite rod as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The three-electrode system is placed in an electrolytic cell, and a prepared aluminum salt / carbon precursor electrolyte is added. Electrochemical deposition is performed under constant potential / constant current to obtain a tightly bonded aluminum / carbon precursor substrate.

[0057] (3) The dried aluminum / carbon precursor substrate is cut into a frame-type aluminum / carbon precursor growth substrate with a specific shape by laser cutting process and auxiliary gas is introduced to prevent the substrate from being oxidized.

[0058] (4) The framework aluminum / carbon precursor growth substrate is transferred to a graphitization furnace for gradient heating carbothermic reduction nitridation reaction. Inert gas is continuously introduced during the reaction. After the reaction, aluminum nitride whiskers / porous carbon composite framework with uniform size and distribution of pores is obtained.

[0059] (5) Mix nitride particle powder, sintering aid and dispersant, and obtain nitride whisker / particle mixed slurry by gas vortex centrifugal homogenization.

[0060] (6) The nitride whisker / particle mixture slurry is sieved and filled into the aluminum nitride whisker / porous carbon composite frame by scraping method, and then the composite plate is obtained by dry pressing.

[0061] (7) The composite plate is hot-pressed and calcined to obtain a nitride nanofiber toughened nitride ceramic substrate. In step (1), the carbon precursor includes one or more of the following: phenolic resin, glucose, sucrose, acetonitrile, dimethylformamide, graphene oxide, carbon nanotubes, etc., with a concentration range of 10-30 wt%; the aluminum salt includes one or more of the following: aluminum sulfate, aluminum chloride, aluminum nitrate, aluminum isopropoxide, aluminum silicate, aluminum sulfide, etc., with a concentration range of 0.1–2.0 M; the supporting electrolyte includes one or more of the following: sulfuric acid, potassium chloride, potassium nitrate, potassium dihydrogen phosphate, tetraethyl hexafluorophosphate, tetrabutyl hexafluorophosphate, tetramethylammonium chloride, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, sodium hydroxide, lithium chloride, lithium perchlorate, etc., with a concentration range of 0.1–1.0 M; the solvent includes one or more of the following: deionized water, anhydrous ethanol, acetonitrile, dimethylformamide, dimethyl sulfoxide, acetone, tetrahydrofuran, etc.

[0062] In step (2), the conductive substrate includes one or more of the following: copper foil, nickel foil, titanium foil, graphite sheet, carbon cloth, carbon paper, tin oxyfluoride glass, indium tin oxide glass, etc., with a surface area of ​​4-9 cm². 2 The surface area of ​​the counter electrode is 8-18 cm². 2 The constant potential has a value of -1.0V to -2.0V (vs. Ag / AgCl); the constant current has a current density of 1–10 mA / cm². 2 The electrochemical deposition time is 10–60 minutes.

[0063] In step (3), the drying temperature is 60-100℃ and the drying time is 1-12h.

[0064] The laser cutting process has a laser power of 10-100W, a cutting speed of 10-500mm / s, and a pulse frequency of 1-100kHz. The auxiliary gas in the laser cutting process includes one or more of nitrogen, argon, etc., with a pressure of 0.5-2bar. The specific shape includes one or more of the following: triangle, quadrilateral, hexagon, circle, quadrilateral with inner diameter triangle, quadrilateral with inner diameter hexagon, circle with inner diameter hexagon, circle with inner diameter quadrilateral, and circle with inner diameter triangle, etc., with a unit inner diameter range of 1-3cm.

[0065] In step (4), the gradient heating carbothermal reduction nitriding process is divided into three stages: a carbon framework formation stage (400-600℃), an in-situ growth stage of aluminum nitride whiskers (800-1000℃), and a composite porous carbon framework formation stage (1400-1600℃). These stages sequentially achieve the removal of volatiles, the carbonization of the carbon precursor to form a carbon framework, the nitridation of the aluminum source to form aluminum nitride whiskers, and the pyrolysis of the carbon framework to form a porous carbon framework. The first stage of the gradient heating carbothermal reduction nitriding process starts from room temperature at a rate of 5-10℃ / min. The process involves three stages: First, heating to 400-600℃ and holding for 1-2 hours in an inert atmosphere. Second, heating to 800-1000℃ at a rate of 3-5℃ / min and holding for 1-1.5 hours. Third, heating to 1400-1600℃ at a rate of 2-3℃ / min and holding for 2-3 hours. The inert gas includes one or more of nitrogen, argon, etc., with a flow rate of 50-500 mL / min. The aluminum nitride whisker / porous carbon composite framework has a pore size range of 10-500 nm and a specific surface area of ​​100-1000 m². 2 / g, with an inner diameter of 1-3cm.

[0066] In step (5), the nitride particle powder includes one or more of aluminum nitride, boron nitride, silicon nitride, gallium nitride, and titanium nitride, with a particle size of 100-500 nm; the sintering aid includes one or more of yttrium oxide, calcium oxide, dysprosium oxide, boron oxide, calcium fluoride, titanium oxide, aluminum oxide, and lithium oxide, accounting for 0.5-5 wt% of the nitride particles; the dispersant includes one or more of anhydrous ethanol, acetone, dichloromethane, chloroform, xylene, and tetrahydrofuran; the gas vortex centrifugal homogenization... The gas used is one or more of nitrogen, argon, etc., with a gas flow rate of 10-20 L / min, a centrifugation speed of 100-2000 rpm, and a homogenization time of 1-5 h. The solid content of the nitride whisker / particle mixed slurry nitride particles is 50-80 wt%, viscosity is <300 mPa·s, ball milling speed is 100-500 rad / min, ball milling time is 1-3 h, ball-to-particle ratio is (1-5):1, viscosity after ball milling is <300 mPa·s, absolute value of zeta potential of slurry is >20 and there is no sedimentation after 24 h.

[0067] In step (6), the sieving is performed using a 200-500 mesh sieve to remove larger particles and agglomerates from the mixed slurry; the viscosity of the nitride whisker / particle mixed slurry is controlled at 1000-5000 MPa·s to facilitate uniform filling. When using the scraping method, the scraping speed is 5-15 cm / min, and the angle between the scraper and the surface of the aluminum nitride whisker / porous carbon composite frame is maintained at 30-60°; when using the impregnation method, the impregnation time is 5-30 min, and the impregnation temperature is controlled at 20-50℃. The dry pressing molding is performed at a pressure of 10-50 MPa and a holding time of 5-30 min to ensure that the mixed slurry fully fills the frame pores and forms the initial shape.

[0068] In step (7), the hot pressing calcination is divided into two stages: the first stage is to raise the temperature from room temperature to 400-600℃ at a rate of 5-8℃ / min and hold it for 1-2 hours in an oxygen atmosphere to achieve the oxidation and removal of residual carbon; the second stage is to switch to an inert atmosphere and raise the temperature to 1600-1900℃ at a rate of 5-10℃ / min, with a hot pressing pressure of 30-60MPa and a holding time of 1-3 hours; the inert gas during the hot pressing calcination process is argon or nitrogen, with a gas flow rate of 100-300mL / min, to prevent the composite plate from oxidizing at high temperature and to ensure that a high-performance nitride nanofiber toughened nitride ceramic substrate is finally obtained.

[0069] The following examples were all prepared using the preparation method described above.

[0070] Example 1 (carbon precursor concentration 10 wt%)

[0071] In this embodiment, in step one, phenolic resin, 0.5M aluminum nitrate and 0.3M tetrabutylammonium hexafluorophosphate are dissolved in anhydrous ethanol and stirred evenly to prepare a carbon precursor / aluminum salt electrolyte, wherein the concentration of phenolic resin is 10wt%.

[0072] In this embodiment, in step two, the surface area is 6 cm². 2 The copper foil is used as the working electrode, with a surface area of ​​12 cm². 2 A platinum sheet was used as the counter electrode, and an Ag / AgCl electrode was used as the reference electrode to assemble a three-electrode system. This system was placed in an electrolytic cell, and the prepared electrolyte was added. Electrochemical deposition was performed at a constant potential of -1.5V (vs. Ag / AgCl) for 30 minutes to obtain a tightly bonded aluminum / carbon precursor substrate.

[0073] In this embodiment, in step three, the aluminum / carbon precursor substrate is dried at 80°C for 6 hours, and then a laser cutting process with a laser power of 50W, a cutting speed of 200mm / s, and a pulse frequency of 50kHz is used. Nitrogen gas with a pressure of 1 bar is introduced as an auxiliary gas to cut the substrate into a frame-type aluminum / carbon precursor growth substrate with a quadrilateral inner diameter of hexagonal and an inner diameter of 2cm.

[0074] In this embodiment, in step four, the growth substrate is transferred to a graphitization furnace. In the first stage, the temperature is increased from room temperature to 500°C at a rate of 8°C / min and held at this temperature for 1.5 hours under an argon atmosphere. In the second stage, the temperature is increased to 900°C at a rate of 4°C / min and held for 1.2 hours. In the third stage, the temperature is increased to 1500°C at a rate of 2.5°C / min and held for 2.5 hours. Argon gas is continuously introduced at a flow rate of 200 mL / min throughout the reaction, resulting in a pore size range of 10-300 nm and a specific surface area of ​​600 m². 2 / g, aluminum nitride whisker / porous carbon composite framework with an inner diameter of 2cm;

[0075] In this embodiment, in step five, aluminum nitride particles with a particle size of 300 nm are taken, and yttrium oxide accounting for 2 wt% of the aluminum nitride particles is added as a sintering aid. Anhydrous ethanol is used as a dispersant. Under a nitrogen atmosphere with a gas flow rate of 15 L / min, the mixture is centrifuged at 1500 rpm for 1.5 hours to obtain a nitride whisker / particle mixed slurry with a solid content of 65 wt% and a viscosity of <300 mPa·s. The ball milling speed is 200 rad / min, the ball milling time is 2 h, the ball-to-particle ratio is 3:1, the viscosity after ball milling is <300 mPa·s, the absolute value of the slurry's Zeta potential is >20 and there is no sedimentation after 24 h.

[0076] In this embodiment, in step six, the mixed slurry is sieved through a 300-mesh sieve to control its viscosity at 3000 MPa·s. The slurry is then coated at a scraping speed of 10 cm / min with the scraper at a 45° angle to the surface of the composite frame. Finally, it is dry-pressed under a pressure of 30 MPa for 15 minutes to obtain the composite board.

[0077] In this embodiment, in step seven, the composite plate is placed in a hot press furnace. In the first stage, the temperature is increased to 500°C at a rate of 5°C / min and held at that temperature for 1.5 hours in an oxygen atmosphere. In the second stage, the temperature is switched to an argon atmosphere and increased to 1700°C at a rate of 5°C / min. A hot pressing pressure of 30 MPa is applied and held for 2 hours. During the hot pressing process, argon gas with a flow rate of 1 L / min is introduced as a protective gas, and finally, a nitride nanofiber toughened nitride ceramic substrate is obtained.

[0078] Figure 1 The cross-sectional microstructure of an aluminum nitride whisker / porous carbon composite framework is shown. The aluminum nitride whiskers grow uniformly in the porous carbon framework, with a high aspect ratio and ordered orientation, and no obvious agglomeration. The resulting composite framework has a uniform pore structure with continuous and interconnected pore distribution, providing an efficient channel for subsequent filling of nitride particles. Figure 2 The frontal SEM microstructure of the aluminum nitride whisker / porous carbon composite framework is shown. The aluminum nitride whiskers and the porous carbon framework are tightly bonded at the interface. The framework exhibits a regular geometric structure with smooth and defect-free edges, demonstrating that laser cutting facilitates high-precision morphology control. Cross-sectional SEM images of the aluminum nitride whisker-reinforced aluminum nitride ceramic matrix composite are also shown. Figure 3 As shown, aluminum nitride particles are uniformly filled in the pores of aluminum nitride whiskers / porous carbon framework without obvious gaps or agglomerates. The composite material exhibits ductile fracture characteristics, which proves that there is a strong interaction between the interface between the nitride particles and the aluminum nitride whiskers / porous carbon composite framework, providing structural support for the high flexural strength and high fracture toughness of the composite material.

[0079] Compared with existing technologies, the prepared aluminum nitride whiskers / porous carbon framework exhibits an ordered whisker distribution. The aluminum nitride whiskers grow directionally under the constraint of the porous carbon framework, simultaneously improving the aspect ratio of the aluminum nitride whiskers and constructing a three-dimensional continuous thermally conductive network. This achieves a synergistic increase in in-plane thermal conductivity (200-260 W / (m·K)) and normal thermal conductivity (180-280 W / (m·K)). Furthermore, gas vortex centrifugal homogenization (nitrogen atmosphere, 1500 rpm centrifugation) ensures molecular-level dispersion of the aluminum nitride particles and sintering aids. Figure 3The uniformly packed particles, combined with 30MPa dry pressing and 1700℃ hot pressing and calcination, achieve a tight bond between the framework and the matrix (porosity as low as 0.1-5%), significantly reducing interface defects. Therefore, the flexural strength (300-500MPa) is more than 50% higher than that of traditional materials (typically <300MPa). The aluminum nitride whiskers, acting as a "reinforcing phase," dissipate energy during fracture through "pull-out effect" and "bridging effect." Figure 3 (Whisker pull-out marks are visible on the cross-section), combined with the flexible support of a porous framework with a high aspect ratio, which increases the fracture toughness to 4-12 MPa·m. 1 / 2 Meanwhile, the high-temperature stability of the composite material (hot-pressing temperature 1600-1900℃) ensures that the material maintains stable performance even in extreme environments, making it suitable for demanding scenarios such as high-power electronic packaging.

[0080] Example 2: (Carbon precursor concentration 20wt%)

[0081] In this embodiment, in step one, glucose, 1.2M aluminum chloride and 0.6M lithium perchlorate are dissolved in acetonitrile and stirred thoroughly to prepare a carbon precursor / aluminum salt electrolyte, wherein the concentration of glucose is 20wt%.

[0082] In this embodiment, in step two, the surface area is 5 cm². 2 Nickel foil is used as the working electrode, with a surface area of ​​10 cm². 2 A graphite rod was used as the counter electrode, and an Ag / AgCl electrode was used as the reference electrode to assemble a three-electrode system. This system was placed in an electrolytic cell, and the prepared electrolyte was added. The current density was 6 mA / cm². 2 Electrochemical deposition was performed under a constant current for 40 minutes to obtain an aluminum / carbon precursor substrate.

[0083] In this embodiment, in step three, the substrate is dried at 70°C for 8 hours, and a laser cutting process with a laser power of 30W, a cutting speed of 150mm / s, and a pulse frequency of 30kHz is used. Argon gas with a pressure of 0.8bar is introduced as an auxiliary gas to cut the substrate into a frame-type aluminum / carbon precursor growth substrate with a circular inner diameter quadrilateral and an inner diameter of 1.5cm.

[0084] In this embodiment, in step four, the growth substrate is placed in a graphitization furnace. In the first stage, the temperature is increased from room temperature to 450°C at a rate of 6°C / min and held at this temperature for 1.8 hours under a nitrogen atmosphere. In the second stage, the temperature is increased to 850°C at a rate of 3°C / min and held for 1.3 hours. In the third stage, the temperature is increased to 1450°C at a rate of 2°C / min and held for 2.2 hours. Nitrogen gas is continuously introduced at a flow rate of 150 mL / min during the reaction, resulting in a pore size range of 50-400 nm and a specific surface area of ​​700 m². 2 / g, aluminum nitride whisker / porous carbon composite framework with an inner diameter of 1.5cm;

[0085] In this embodiment, in step five, silicon nitride particle powder with a particle size of 200 nm is selected, and boron oxide accounting for 3 wt% of the silicon nitride particles is added as a sintering aid. Acetone is used as a dispersant, and the mixture is homogenized by gas vortex centrifugation at a speed of 1200 rpm for 2 hours under an argon atmosphere with a gas flow rate of 12 L / min to obtain a nitride whisker / particle mixed slurry with a solid content of 70 wt% and a viscosity of <300 mPa·s. The ball milling speed is 300 rad / min, the ball milling time is 1.5 h, the ball-to-particle ratio is 2:1, the viscosity after ball milling is <300 mPa·s, the absolute value of the slurry's Zeta potential is >20 and there is no sedimentation after 24 h.

[0086] In this embodiment, in step six, the mixed slurry is sieved through a 400-mesh sieve to make its viscosity reach 2500 mpa·s. It is then coated at a scraping speed of 8 cm / min with the scraper at a 50° angle to the surface of the composite frame. Subsequently, it is dry-pressed under a pressure of 25 MPa for 20 minutes to obtain the composite board.

[0087] In this embodiment, in step seven, the composite plate is placed in a hot press furnace. In the first stage, the temperature is raised to 450°C at a rate of 6°C / min and held at that temperature for 1.8 hours in an oxygen atmosphere. In the second stage, the temperature is switched to a nitrogen atmosphere and raised to 1800°C at a rate of 6°C / min. A hot pressing pressure of 45 MPa is applied and held for 1.8 hours. During the hot pressing process, nitrogen gas with a flow rate of 180 mL / min is introduced for protection, and finally, a nitride nanofiber toughened nitride ceramic substrate is obtained.

[0088] Example 3: (Carbon precursor concentration 30wt%)

[0089] In this embodiment, in step one, sucrose, 2.0M aluminum sulfate and 1.0M potassium chloride are dissolved in dimethylformamide and stirred until completely dissolved to prepare a carbon precursor / aluminum salt electrolyte, wherein the concentration of sucrose is 30wt%.

[0090] In this embodiment, in step two, the surface area is 7 cm². 2 Titanium foil is used as the working electrode, with a surface area of ​​15 cm². 2 A graphite rod was used as the counter electrode, and an Ag / AgCl electrode was used as the reference electrode to assemble a three-electrode system. The three-electrode system was placed in an electrolytic cell, and the prepared electrolyte was added. The electrolyte was then applied at 8 mA / cm². 2 Electrochemical deposition was performed under specific conditions for 50 minutes to obtain a tightly bonded aluminum / carbon precursor substrate.

[0091] In this embodiment, in step three, the aluminum / carbon precursor substrate is dried at 90°C for 4 hours, and then a laser cutting process with a laser power of 80W, a cutting speed of 300mm / s, and a pulse frequency of 70kHz is used. Nitrogen gas with a pressure of 1.5bar is introduced as an auxiliary gas to cut the substrate into a frame-type aluminum / carbon precursor growth substrate with a hexagonal inner diameter triangle and an inner diameter of 2.5cm.

[0092] In this embodiment, in step four, the growth substrate is transferred to a graphitization furnace. In the first stage, the temperature is increased from room temperature to 550°C at a rate of 9°C / min and held at this temperature for 1.2 hours under a nitrogen atmosphere. In the second stage, the temperature is increased to 950°C at a rate of 5°C / min and held for 1.4 hours. In the third stage, the temperature is increased to 1550°C at a rate of 3°C / min and held for 2.8 hours. Argon gas is continuously introduced at a flow rate of 300 mL / min throughout the reaction, resulting in a pore size range of 50-450 nm and a specific surface area of ​​800 m². 2 / g, aluminum nitride whisker / porous carbon composite framework with an inner diameter of 2.5cm.

[0093] In this embodiment, in step five, boron nitride particle powder with a particle size of 500 nm is taken, and dysprosium oxide accounting for 4 wt% of the boron nitride particles is added as a sintering aid. Chloroform is used as a dispersant. Under an argon atmosphere with a gas flow rate of 18 L / min, the mixture is centrifuged at 1800 rpm for 3 hours to obtain a nitride whisker / particle mixed slurry with a solid content of 75 wt% and a viscosity of <300 mPa·s. The ball milling speed is 400 rad / min, the ball milling time is 2.5 hours, the ball-to-particle ratio is 4:1, the viscosity after ball milling is <300 mPa·s, the absolute value of the slurry's Zeta potential is >20 and there is no sedimentation after 24 hours.

[0094] In this embodiment, in step six, the mixed slurry is sieved through a 200-mesh sieve to control its viscosity at 4000 MPa·s. The slurry is then coated at a scraping speed of 12 cm / min with the scraper at a 55° angle to the surface of the composite frame. Finally, it is dry-pressed under a pressure of 40 MPa for 25 min to obtain the composite board.

[0095] In this embodiment, in step seven, the composite plate is placed in a hot press furnace. In the first stage, the temperature is increased to 550°C at a rate of 7°C / min and held at that temperature for 1.2 hours in an oxygen atmosphere. In the second stage, the temperature is switched to a nitrogen atmosphere and increased to 1850°C at a rate of 7°C / min. A hot pressing pressure of 60 MPa is applied and held for 2.5 hours. During the hot pressing process, nitrogen gas with a flow rate of 250 mL / min is introduced for protection, and finally, a nitride nanofiber toughened nitride ceramic substrate is obtained.

[0096] Comparative Example 1 (carbon precursor concentration 5 wt%)

[0097] In this comparative example, in step one, phenolic resin, 0.5M aluminum nitrate and 0.3M tetrabutylammonium hexafluorophosphate were dissolved in anhydrous ethanol and stirred until homogeneous to prepare a carbon precursor / aluminum salt electrolyte; wherein, the concentration of phenolic resin was 5wt%.

[0098] In this comparative example, in step two, the surface area is 6 cm². 2 The copper foil is used as the working electrode, with a surface area of ​​12 cm². 2 A platinum sheet was used as the counter electrode, and an Ag / AgCl electrode was used as the reference electrode to assemble a three-electrode system. This system was placed in an electrolytic cell, and the prepared electrolyte was added. Electrochemical deposition was performed at a constant potential of -1.5V (vs. Ag / AgCl) for 30 minutes to obtain a tightly bonded aluminum / carbon precursor substrate.

[0099] In this comparative example, in step three, the aluminum / carbon precursor substrate was dried at 80°C for 6 hours, and then a laser cutting process with a laser power of 50W, a cutting speed of 200mm / s, and a pulse frequency of 50kHz was used. Nitrogen gas with a pressure of 1 bar was introduced as an auxiliary gas to cut the substrate into a frame-type aluminum / carbon precursor growth substrate with a quadrilateral inner diameter of hexagonal and an inner diameter of 2cm.

[0100] In this comparative example, in step four, the growth substrate was transferred to a graphitization furnace. In the first stage, the temperature was increased from room temperature to 500°C at a rate of 8°C / min and held at this temperature for 1.5 hours under an argon atmosphere. In the second stage, the temperature was increased to 900°C at a rate of 4°C / min and held for 1.2 hours. In the third stage, the temperature was increased to 1500°C at a rate of 2.5°C / min and held for 2.5 hours. Argon gas was continuously introduced at a flow rate of 200 mL / min throughout the reaction, resulting in a pore size range of 10-300 nm and a specific surface area of ​​600 m². 2 / g, aluminum nitride whisker / porous carbon composite framework with an inner diameter of 2cm;

[0101] In this comparative example, in step five, aluminum nitride particles with a particle size of 300 nm were taken, and yttrium oxide accounting for 2 wt% of the aluminum nitride particles was added as a sintering aid. Anhydrous ethanol was used as a dispersant. Under a nitrogen atmosphere with a gas flow rate of 15 L / min, the mixture was centrifuged at 1500 rpm for 1.5 hours to obtain a nitride whisker / particle mixture slurry with a solid content of 65 wt% and a viscosity of <300 mPa·s. The ball milling speed was 200 rad / min, the ball milling time was 2 h, the ball-to-particle ratio was 3:1, the viscosity after ball milling was <300 mPa·s, the absolute value of the zeta potential of the slurry was >20 and there was no sedimentation after 24 h.

[0102] In this comparative example, in step six, the mixed slurry is sieved through a 300-mesh sieve to control its viscosity at 3000 mpa·s. The slurry is then applied at a scraping speed of 10 cm / min with the scraper at a 45° angle to the surface of the composite frame. Finally, it is dry-pressed under a pressure of 30 MPa for 15 minutes to obtain the composite board.

[0103] In this comparative example, in step seven, the composite plate was placed in a hot press furnace. In the first stage, the temperature was increased to 500℃ at a rate of 5℃ / min and held for 1.5 hours in an oxygen atmosphere. In the second stage, the temperature was switched to an argon atmosphere and increased to 1700℃ at a rate of 5℃ / min. A hot pressing pressure of 50 MPa was applied and held for 2 hours. During the hot pressing process, argon gas was introduced at a flow rate of 200 mL / min for protection. The final product was a nitride nanofiber-reinforced nitride ceramic substrate. Due to the low concentration of the carbon precursor, the carbon framework could not form a continuous structure, resulting in insufficient support for the growth of aluminum nitride whiskers, with a whisker aspect ratio of only 35-40. The material had a flexural strength of 210 MPa and a fracture toughness of 2.8 MPa·m. 1 / 2 The porosity is as high as 9.5%, the in-plane thermal conductivity is only 150 W / (m·K), and the normal thermal conductivity is 120 W / (m·K), and the overall performance is significantly lower than that of the embodiment of the present invention.

[0104] Comparative Example 2 (carbon precursor concentration 35 wt%)

[0105] In this comparative example, in step one, phenolic resin, 0.5M aluminum nitrate and 0.3M tetrabutylammonium hexafluorophosphate were dissolved in anhydrous ethanol and stirred evenly to prepare a carbon precursor / aluminum salt electrolyte, wherein the concentration of phenolic resin was 35wt%.

[0106] In this comparative example, in step two, the surface area is 6 cm². 2 The copper foil is used as the working electrode, with a surface area of ​​12 cm². 2 A platinum sheet was used as the counter electrode, and an Ag / AgCl electrode was used as the reference electrode to assemble a three-electrode system. This system was placed in an electrolytic cell, and the prepared electrolyte was added. Electrochemical deposition was performed at a constant potential of -1.5V (vs. Ag / AgCl) for 30 minutes to obtain a tightly bonded aluminum / carbon precursor substrate.

[0107] In this comparative example, in step three, the aluminum / carbon precursor substrate was dried at 80°C for 6 hours, and then a laser cutting process with a laser power of 50W, a cutting speed of 200mm / s, and a pulse frequency of 50kHz was used. Nitrogen gas with a pressure of 1 bar was introduced as an auxiliary gas to cut the substrate into a frame-type aluminum / carbon precursor growth substrate with a quadrilateral inner diameter of hexagonal and an inner diameter of 2cm.

[0108] In this comparative example, in step four, the growth substrate was transferred to a graphitization furnace. In the first stage, the temperature was increased from room temperature to 500°C at a rate of 8°C / min and held at this temperature for 1.5 hours under an argon atmosphere. In the second stage, the temperature was increased to 900°C at a rate of 4°C / min and held for 1.2 hours. In the third stage, the temperature was increased to 1500°C at a rate of 2.5°C / min and held for 2.5 hours. Argon gas was continuously introduced at a flow rate of 200 mL / min throughout the reaction, resulting in a pore size range of 10-300 nm and a specific surface area of ​​600 m². 2 / g, aluminum nitride whisker / porous carbon composite framework with an inner diameter of 2cm;

[0109] In this comparative example, in step five, aluminum nitride particles with a particle size of 300 nm were taken, and yttrium oxide accounting for 2 wt% of the aluminum nitride particles was added as a sintering aid. Anhydrous ethanol was used as a dispersant. Under a nitrogen atmosphere with a gas flow rate of 15 L / min, the mixture was centrifuged at 1500 rpm for 1.5 hours to obtain a nitride whisker / particle mixture slurry with a solid content of 65 wt% and a viscosity of <300 mPa·s. The ball milling speed was 200 rad / min, the ball milling time was 2 h, the ball-to-particle ratio was 3:1, the viscosity after ball milling was <300 mPa·s, the absolute value of the zeta potential of the slurry was >20 and there was no sedimentation after 24 h.

[0110] In this comparative example, in step six, the mixed slurry is sieved through a 300-mesh sieve to control its viscosity at 3000 mpa·s. The slurry is then applied at a scraping speed of 10 cm / min with the scraper at a 45° angle to the surface of the composite frame. Finally, it is dry-pressed under a pressure of 30 MPa for 15 minutes to obtain the composite board.

[0111] In this comparative example, in step seven, the composite plate was placed in a hot press furnace. In the first stage, the temperature was increased to 500℃ at a rate of 5℃ / min and held for 1.5 hours in an oxygen atmosphere. In the second stage, the temperature was switched to an argon atmosphere and increased to 1700℃ at a rate of 5℃ / min. A hot pressing pressure of 50 MPa was applied and held for 2 hours. During the hot pressing process, argon gas was introduced at a flow rate of 200 mL / min for protection. The final product was a nitride nanofiber-reinforced nitride ceramic substrate. The resulting composite material had an excessively high carbon precursor concentration, leading to overly dense carbon framework that hindered nitrogen atom diffusion, incomplete nitriding reaction, and a large amount of carbon impurities remaining on the whisker surface. The material had a flexural strength of 250 MPa and a fracture toughness of 3.2 MPa·m. 1 / 2 The porosity is 8.2%, the in-plane thermal conductivity is 170 W / (m·K), and the normal thermal conductivity is 150 W / (m·K). All of these performance indicators are inferior to those of the embodiments of the present invention, which verifies the negative effects when the carbon precursor concentration exceeds the range of 10-30 wt%.

[0112] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing a high thermal conductivity nitride ceramic whisker-reinforced nitride ceramic matrix composite material, characterized in that, Includes the following steps: Step 1: Dissolve the carbon precursor and aluminum salt in a solvent containing a supporting electrolyte to prepare a carbon precursor / aluminum salt electrolyte. Step 2: Place the conductive substrate in the carbon precursor / aluminum salt electrolyte obtained in Step 1 and perform electrochemical deposition to obtain the aluminum / carbon precursor substrate. Step 3: Cut the aluminum / carbon precursor substrate obtained in Step 2 into a frame-type aluminum / carbon precursor growth substrate. Step 4: Transfer the framework aluminum / carbon precursor growth substrate obtained in Step 3 to a graphitization furnace for gradient heating carbothermic reduction nitridation reaction. Inert gas is continuously introduced during the reaction. After the reaction, aluminum nitride whiskers / porous carbon composite framework is obtained. Step 5: Mix the nitride particle powder, sintering aid and dispersant to obtain a mixed slurry; Step 6: Fill the mixed slurry obtained in Step 5 into the aluminum nitride whisker / porous carbon composite framework obtained in Step 4, and dry press to form a composite plate; Step 7: Hot-press and calcinate the composite plate obtained in Step 6 to obtain a nitride nanofiber toughened nitride ceramic substrate.

2. The method for preparing a high thermal conductivity nitride ceramic whisker-reinforced nitride ceramic matrix composite material according to claim 1, characterized in that, In step one: The carbon precursor includes one or more of phenolic resin, glucose, sucrose, acetonitrile, dimethylformamide, graphene oxide, and carbon nanotubes, and the concentration of the carbon precursor in the electrolyte ranges from 10 to 30 wt%. The aluminum salt includes one or more of aluminum sulfate, aluminum chloride, aluminum nitrate, aluminum isopropoxide, aluminum silicate, and aluminum sulfide, and the concentration of the aluminum salt in the electrolyte ranges from 0.1 to 2.0 M. The supporting electrolyte includes one or more of the following: sulfuric acid, potassium chloride, potassium nitrate, potassium dihydrogen phosphate, tetraethylammonium hexafluorophosphate, tetrabutylammonium hexafluorophosphate, tetramethylammonium chloride, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, sodium hydroxide, lithium chloride, and lithium perchlorate. The concentration of the supporting electrolyte in the electrolyte is in the range of 0.1-1.0 M. The solvent includes one or more of deionized water, anhydrous ethanol, acetonitrile, dimethylformamide, dimethyl sulfoxide, acetone, and tetrahydrofuran.

3. The method for preparing a high thermal conductivity nitride ceramic whisker-reinforced nitride ceramic matrix composite material according to claim 1, characterized in that, In step two, the electrochemical deposition specifically involves: A three-electrode system is assembled by using a conductive substrate as the working electrode, a platinum sheet or graphite rod as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The three-electrode system is placed in an electrolytic cell, and a prepared aluminum salt / carbon precursor electrolyte is added. Electrochemical deposition is carried out under constant potential / constant current to obtain a tightly bonded aluminum / carbon precursor substrate.

4. The method for preparing a high thermal conductivity nitride ceramic whisker-reinforced nitride ceramic matrix composite material according to claim 3, characterized in that, The conductive substrate includes one or more of the following: copper foil, nickel foil, titanium foil, graphite sheet, carbon cloth, carbon paper, tin oxide glass, and indium tin oxide glass. The constant potential has a value of -1.0V to -2.0V (vs. Ag / AgCl); The current density of the constant current is 1–10 mA / cm². 2 ; The electrochemical deposition time is 10–60 minutes.

5. The method for preparing a high thermal conductivity nitride ceramic whisker-reinforced nitride ceramic matrix composite material according to claim 1, characterized in that, In step three, the cutting is laser cutting. The laser cutting process has a laser power of 10-100W, a cutting speed of 10-500mm / s, and a pulse frequency of 1-100kHz. The auxiliary gas for the laser cutting process includes one or more of nitrogen and argon, with a pressure of 0.5-2 bar. The shape of the frame-type aluminum / carbon precursor growth substrate includes one or more of the following: triangle, quadrilateral, hexagon, circle, quadrilateral with inner diameter triangle, quadrilateral with inner diameter hexagon, circle with inner diameter hexagon, circle with inner diameter quadrilateral, and circle with inner diameter triangle. When the shape of the frame-type aluminum / carbon precursor growth substrate has an inner diameter, the inner diameter ranges from 1 to 3 cm.

6. The method for preparing a high thermal conductivity nitride ceramic whisker-reinforced nitride ceramic matrix composite material according to claim 1, characterized in that, In step four: The gradient heating carbothermic reduction nitriding process consists of three stages. The first stage involves heating from room temperature to 400-600℃ at a rate of 5-10℃ / min and holding for 1-2 hours under an inert atmosphere to remove volatile components and carbonize the carbon precursor to form a carbon framework. The second stage involves heating to 800-1000℃ at a rate of 3-5℃ / min and holding for 1-1.5 hours to nitrid the aluminum source and form aluminum nitride whiskers. The third stage involves heating to 1400-1600℃ at a rate of 2-3℃ / min and holding for 2-3 hours to pyrolyze the carbon framework and form a porous aluminum carbide framework. The inert gas includes one or more of nitrogen and argon; The aluminum nitride whisker / porous carbon composite framework has a pore size range of 10-500 nm and a specific surface area of ​​100-1000 m². 2 / g, with an inner diameter of 1-3cm.

7. The method for preparing a high thermal conductivity nitride ceramic whisker-reinforced nitride ceramic matrix composite material according to claim 1, characterized in that, In step five: The nitride particle powder includes one or more of aluminum nitride, boron nitride, silicon nitride, gallium nitride, and titanium nitride, and the particle size is 0.1μm-1μm; The sintering aids include one or more of yttrium oxide, calcium oxide, dysprosium oxide, boron oxide, calcium fluoride, titanium oxide, aluminum oxide, and lithium oxide, accounting for 0.5 to 5 wt% of the nitride particles; The dispersant includes one or more of anhydrous ethanol, acetone, dichloromethane, chloroform, xylene, and tetrahydrofuran; The solid content of the nitride particles in the nitride whisker / particle mixed slurry is 50-80 wt%, and the viscosity is <300 mPa·s; The nitride particulate powder, sintering aid and dispersant are homogenized by gas vortex centrifugation, wherein the gas in the gas vortex centrifugation is one or more of nitrogen and argon, the gas flow rate is 10-20 L / min, the centrifugation speed is 100-2000 rpm, and the homogenization time is 1-5 h.

8. The method for preparing a high thermal conductivity nitride ceramic whisker-reinforced nitride ceramic matrix composite material according to claim 1, characterized in that, In step six, the mixed slurry needs to be sieved before filling, and the sieved mixed slurry is filled by scraping. The sieving process uses a 200-500 mesh sieve to remove larger particles and agglomerates from the mixed slurry. The scraping speed is 5-15 cm / min, and the angle between the scraper and the surface of the aluminum nitride whisker / porous carbon composite framework is maintained at 30-60°. The dry pressing process involves a pressure of 10-50 MPa and a holding time of 5-30 minutes to ensure that the mixed slurry fully fills the pores of the frame and forms the initial shape.

9. The method for preparing a high thermal conductivity nitride ceramic whisker-reinforced nitride ceramic matrix composite material according to claim 1, characterized in that, In step seven: The hot-pressing calcination process consists of two stages: the first stage involves heating from room temperature to 400-600℃ at a rate of 5-8℃ / min and holding at that temperature for 1-2 hours in an oxygen atmosphere to remove residual carbon through oxidation; the second stage involves switching to an inert atmosphere and heating to 1600-1900℃ at a rate of 5-10℃ / min, with a hot-pressing pressure of 30-60MPa and a holding time of 1-3 hours. The hot-pressing calcination process is carried out under an inert gas protective atmosphere, with the inert gas being argon or nitrogen at a flow rate of 1-3L / min, to prevent oxidation of the composite board at high temperatures and ensure the final product is a high-performance nitride nanofiber-reinforced nitride ceramic substrate.

10. A high thermal conductivity nitride ceramic whisker-reinforced nitride ceramic matrix composite material, characterized in that, The material is prepared by the preparation method described in any one of claims 1-9; The nitride ceramic matrix composite material has a flexural strength of 300-500 MPa and a fracture toughness of 4-12 MPa·m. 1 / 2 The porosity is 0.1-5%, the in-plane thermal conductivity is 200-260 W / (m·K), and the normal thermal conductivity is 180-280 W / (m·K).

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