Sol-gel modification device and method for ceramic powder

Abstract

The invention discloses a sol-gel modification device and method for ceramic powder, the sol-gel modification device comprises a mixing drum and a base, the mixing drum is used for being placed on the base, and the mixing drum comprises a mixing drum upper section and a mixing drum lower section; a hollow closed cavity is formed in the upper section of the stirring barrel, a multi-channel condensation pipe is arranged in the hollow closed cavity, a plurality of condensation pipes of the multi-channel condensation pipe are communicated with one another, the end parts of at least two condensation pipes are communicated with the interior of the stirring barrel, at least one condensation pipe is communicated with the exterior of the upper section of the stirring barrel through an air outlet, and a plug is arranged on the air outlet; a water cooling chamber is defined between the multi-channel condensation pipe and the inner wall of the stirring barrel; an ultrasonic transmitter is arranged in the base and abuts against a top plate of the base through an ultrasonic transducer. And a heating disc is arranged above a top plate of the base. And when gel is formed through heating and stirring, the auxiliary effect of ultrasonic waves is applied, and the dispersion uniformity and the coating uniformity of the micro-nano ceramic powder in the gel are improved.

Description

Technical Field

[0001] This invention relates to the field of ceramic powder modification technology, specifically to a sol-gel modification device and method for ceramic powder. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] Sol-gel modification technology is an advanced method for preparing inorganic or organic-inorganic hybrid materials through solution chemical reactions. Its core involves forming a sol through the dissolution and hydrolysis of precursors, followed by gelation, drying, and heat treatment to obtain the target material. Sol-gel modification technology initially achieved significant results in the field of tool coatings. For example, coating cemented carbide surfaces with an alumina (Al2O3) ceramic layer can significantly improve the strength, wear resistance, and toughness of tools. In recent years, this technology has expanded to areas such as glass coatings, functional ceramic powders, antioxidant materials, and slurry rheological property optimization, and has shown potential application value in the surface modification of photopolymerizable 3D printing ceramic powders.

[0004] Non-oxide ceramics, such as silicon carbide (SiC) and silicon nitride (Si3N4), face challenges in photopolymerization 3D printing technologies, including stereolithography (SLA) and digital light processing (DLP). These challenges primarily stem from the physical properties of these materials, especially their high refractive index and absorbance, which affect the propagation of ultraviolet light and the curing efficiency during photopolymerization. To address these issues, surface modification of ceramic powders with high absorbance and refractive index is necessary. Sol-gel modification technology has multifaceted effects on ceramic particles. This modification technique can reduce the absorbance of ceramic powder, improve the compatibility between ceramic particles and the matrix material during photopolymerization, enhance their dispersibility and interfacial bonding strength, thereby improving the performance of the composite material.

[0005] However, traditional sol-gel modification technology typically uses static gelation or mechanical stirring to coat powders, which has the following technical drawbacks: due to the lack of effective dynamic dispersion methods, powders are prone to agglomeration in the sol, resulting in uneven coating; static or simple stirring can easily form coatings that are too thick or too thin in certain areas, or even produce defects such as pores and cracks; traditional methods are difficult to apply to the uniform coating of high solid content or nanoscale powders, limiting their widespread application in fields such as precision ceramics and composite materials. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a sol-gel modification device and method for ceramic powders. This device and method can apply ultrasonic waves to assist in the formation of a gel while heating and stirring, thereby increasing the dispersion and coating uniformity of micro- and nano-ceramic powders in the gel. This effectively reduces the absorbance and refractive index of non-oxide ceramic powders, enabling the sol-gel modification technology to be better applied in the field of photopolymerization 3D printing.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a sol-gel modification apparatus for ceramic powder, comprising a stirring cylinder and a base, wherein the stirring cylinder is placed on the base, and wherein... The mixing drum includes an upper section and a lower section, which are detachably connected by a connecting structure. The upper section of the stirring drum forms a hollow sealed chamber, in which a multi-channel condenser is installed. The multiple condensers of the multi-channel condenser are interconnected. The ends of at least two condensers are connected to the inside of the stirring drum, and at least one condenser is connected to the outside of the upper section of the stirring drum through an air outlet. A plug is installed on the air outlet. A water-cooled chamber is formed between the multi-channel condenser tube and the inner wall of the stirring drum. The water-cooled chamber is equipped with a water inlet and a water outlet. An ultrasonic transmitter is installed inside the base, and the ultrasonic transmitter abuts against the top plate of the base through an ultrasonic transducer. A heating plate is installed on the top plate of the base.

[0008] Secondly, the present invention provides a sol-gel modification method for ceramic powder, comprising the following steps: After mixing the prepared metal alkoxide with the solvent, place the mixture in a stirring tank, add a magnetic rotor, and assemble the device. Simultaneously activate ultrasound (50-150 kHz), magnetic stirring (0-600 rpm), and heating system (60-85 ℃) to promote the metal alkoxide to complete the transformation process from dissolution to hydrolysis. The formation of sol is determined by the Tyndall effect (usually takes 30-300 min). The gas outlet is opened to allow the reactant gas to pass through a multi-channel condenser, with most of the vapor being condensed and refluxed; excess gas is discharged in a directed manner; and the system pressure is stabilized at 0.1-0.3 MPa. After the sol stabilizes, ceramic powder (particle size 0.5-5 μm) is added through the gas outlet, and a three-dimensional gel network is constructed on the powder surface through continuous polycondensation reaction; Then, after stopping stirring and sonication, gradually increase the temperature to dry the gel.

[0009] After drying, the gel is removed from the mixing tank and the mixing tank is cleaned with ultrasonic waves. Finally, the densified ceramic material is obtained by sintering at 800-1200℃.

[0010] The beneficial effects achieved by one or more embodiments of the present invention described above are as follows: 1. This invention applies ultrasonic vibration to a sol-gel system using an ultrasonic transmitter and transducer, generating multiple synergistic effects: First, it significantly accelerates the hydrolysis reaction of metal alkoxides, forming a more stable colloidal system; second, it effectively inhibits ceramic powder agglomeration, promotes uniform mixing of components, eliminates phase separation caused by concentration gradients, and reduces surface defects in the coating layer; more importantly, it achieves a three-dimensional uniform distribution of ceramic powder in the gel matrix, simultaneously improving coating efficiency and uniformity; finally, it refines the gel network structure through ultrasonic cavitation, resulting in smaller average pore size and superior mechanical properties. This invention achieves comprehensive optimization from the molecular scale to macroscopic properties.

[0011] 2. This invention proposes an innovative solution to the key technical difficulties in the sol-gel preparation process. The method first dissolves and hydrolyzes metal alkoxides in acidic or alkaline solvents through heating to generate active monomers, which are then polymerized to form a sol system. Subsequently, under constant temperature conditions of 60-85℃, continuous heating and stirring promote the condensation of monomers on the surface of the coated powder to form a three-dimensional network gel. A multi-channel condenser is used during the process to achieve triple control: 1) By precisely controlling the solvent evaporation rate through condensation reflux, it can prevent gel formation failure caused by open operation and avoid the risk of pressure buildup in closed systems. 2) Combined with the water-cooled chamber, it achieves precise temperature control (±2℃) and eliminates local overheating; 3) Maintaining a stable reaction environment significantly reduces the defect rate of the coating layer (reduced cracks and decreased porosity).

[0012] This integrated system, through the synchronous operation of heating, stirring, and ultrasonic devices, can ultimately obtain a uniformly coated material with high cross-linking degree and excellent mechanical properties.

[0013] 3. This invention employs a closable plug structure for the stirring tank's vent, enabling staged control: the vent remains sealed during the sol formation stage; during the gel formation stage, the vent is opened to promptly release byproducts such as water, alcohols, and gases, accelerating the reaction rate while preventing pressure buildup and the risk of explosion. This invention innovatively combines the vent with a feeding channel; ceramic powder can be added by removing the plug, achieving a fully sealed operation and effectively preventing personnel injury caused by the volatilization of metal alkoxides and acid / alkali solvents, thus improving experimental safety. Resealing after feeding promotes gel drying, ultimately forming a metal oxide-coated powder. This integrated design significantly enhances experimental safety and operational convenience.

[0014] 4. During the experiment, the metal alkoxides and acid / base solvents used in gel preparation will leave acidic or alkaline residues on the walls of the stirring tank. Ultrasonic vibration cleaning technology offers two advantages: firstly, it reduces the risk of workers coming into contact with harmful substances through non-contact cleaning; secondly, it significantly improves cleaning efficiency by utilizing the cavitation effect of ultrasound. The waste liquid after cleaning can be directly discharged through a tap, achieving contactless operation. Attached Figure Description

[0015] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0016] Figure 1 This is a schematic diagram of the ultrasonic-assisted stirring sol-gel modification device proposed in this invention. Figure 2 This is an exploded view of the ultrasonic-assisted stirring sol-gel modification device proposed in this invention; Figure 3 This is a cross-sectional view of the upper end of the condenser tube of the ultrasonic-assisted stirring sol-gel modification device proposed in this invention. Figure 4 This is a schematic diagram of the connecting clip structure of the ultrasonic-assisted stirring sol-gel modification device proposed in this invention.

[0017] Figure 5 This is a cross-sectional view of the base structure of the ultrasonic-assisted stirring sol-gel modification device proposed in this invention.

[0018] In the diagram, 1-upper section of the mixing drum; 2-connecting clamp; 3-lower section of the mixing drum; 4-base; 5-heating plate; 6-ultrasonic transducer; 7-water tank; 8-water outlet pipe; 9-water pump; 10-multi-channel condenser pipe; 11-air outlet; 12-stopper; 13-faucet; 14-ultrasonic transmitter; 15-magnetic stirrer; 16-water inlet; 17-water outlet. Detailed Implementation

[0019] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] In a first aspect, the present invention provides a sol-gel modification apparatus for ceramic powder, comprising a stirring cylinder and a base, wherein the stirring cylinder is placed on the base, and wherein... The mixing drum includes an upper section and a lower section, which are detachably connected by a connecting structure. The upper section of the stirring drum forms a hollow sealed chamber, in which a multi-channel condenser is installed. The multiple condensers of the multi-channel condenser are interconnected. The ends of at least two condensers are connected to the inside of the stirring drum, and at least one condenser is connected to the outside of the upper section of the stirring drum through an air outlet. A plug is installed on the air outlet. A water-cooled chamber is formed between the multi-channel condenser tube and the inner wall of the stirring drum. The water-cooled chamber is equipped with a water inlet and a water outlet. An ultrasonic transmitter is installed inside the base, and the ultrasonic transmitter abuts against the top plate of the base through an ultrasonic transducer. A heating plate is installed on the top plate of the base.

[0021] A gas outlet is located on the upper right side of the stirring drum, connected to a gas discharge pipe, allowing some of the gas generated during stirring to escape. The upper right side of the stirring drum is also connected to a multi-pipe condenser reflux pipe. This pipe allows some of the gas generated during stirring to flow back into the stirring drum through internal pipes, promoting gel formation.

[0022] In some embodiments, a first annular flange is provided on the bottom outer wall of the upper section of the stirring drum, and a second annular flange is provided on the top outer wall of the lower section of the stirring drum. The first and second annular flanges are engaged and fixed by a snap-fit ​​structure. This method of connection is simple in structure and convenient in operation.

[0023] Preferably, the shapes of the first annular flange and the second annular flange are adapted to the shape of the stirring tank.

[0024] Preferably, a sealing strip is provided at the connection between the upper and lower sections of the mixing drum to prevent liquid from flowing out of the mixing drum.

[0025] In some embodiments, a magnetic stirrer is provided within the base. The magnetic stirrer facilitates the sol-gel process by agitating the particles.

[0026] In some embodiments, a water tap is provided on the bottom side wall of the lower section of the mixing tank. The water tap facilitates the drainage of liquids inside the mixing tank, including cleaning waste liquid.

[0027] In some embodiments, the system further includes a water tank, an outlet pipe, a return pipe, and a water pump. The water pump is installed on the water tank and connected to the inside of the water tank. The outlet of the water pump is connected to the inlet of the water-cooled chamber through the outlet pipe, and the outlet of the water-cooled chamber is connected to the inside of the water tank through the return pipe.

[0028] The water tank contains a large amount of water, which is circulated into the water-cooled chamber of the mixing drum by a circulating water pump to condense and reflux the gas.

[0029] To ensure the effective condensation and reflux of the gas, the temperature of the circulating water needs to be kept low. The circulating water can also be cooled using conventional methods, such as using a heat exchanger.

[0030] In some embodiments, the water inlet of the water-cooled chamber is located below the water outlet. This arrangement maintains a high water level in the water-cooled chamber, which is beneficial for cooling the gas.

[0031] In some embodiments, the heating plate is made of aluminum alloy and has a corrosion-resistant coating sprayed on its upper surface as a protective layer. The resistance wire is made of nickel-chromium alloy and has an aluminum oxide coating sprayed on its surface. A ceramic fiber board (heat resistant to about 1000℃) is provided at the bottom of the heating plate as a heat insulation layer.

[0032] Secondly, the present invention provides a sol-gel modification method for ceramic powder, comprising the following steps: 1) Raw material mixing stage: After mixing the prepared metal alkoxide with the solvent, place it into a stirring tank, add a magnetic rotor, and seal and assemble the reaction device.

[0033] 2) Sol formation stage: Simultaneously start ultrasound (50-150 kHz), magnetic stirring (0-600 rpm) and heating system (60-85 ℃) to promote the metal alkoxide to complete the transformation process of dissolution → hydrolysis. Sol formation is determined by Tyndall effect (usually takes 30-300 minutes).

[0034] 3) Gas regulation stage: Open the gas outlet to allow the reaction gas to pass through the multi-channel condenser, and most of the vapor is condensed and refluxed; excess gas is discharged in a directional manner; the system pressure is stabilized at 0.1-0.3 MPa.

[0035] 4) Powder coating stage: After the sol stabilizes, ceramic powder (particle size 0.5-5 μm) is added through the gas outlet, and a three-dimensional gel network is constructed on the powder surface through continuous polycondensation reaction.

[0036] 5) Post-processing stage: After stopping stirring and sonication, the temperature is gradually increased to 120 ℃ to dry the gel. After drying, the gel is removed from the stirring tank and the stirring tank is cleaned with ultrasonic waves. Finally, the densified ceramic material is obtained by sintering at 800-1200 ℃.

[0037] In some embodiments, the raw materials include aluminum isopropoxide, aluminum sec-butoxide, nitric acid, or sodium hydroxide.

[0038] In some embodiments, the heating temperature is 60-85°C.

[0039] In some embodiments, the temperature of the circulating condensate is 0-10°C.

[0040] In some embodiments, the ultrasonic transmitter operates at a frequency of 50-150 kHz and a power of 300-1200 W.

[0041] In some embodiments, the stirring speed of the magnetic stirrer is 0-600 r / min.

[0042] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0043] like Figure 1-4 As shown, an ultrasonic-assisted stirring sol-gel modification device includes an upper section 1 of a stirring drum, a connecting clamp 2, a lower section 3 of a stirring drum, a base 4, a heating plate 5, a water tank 7, a water pipe 8, a water pump 9, a multi-channel condenser tube 10, an air outlet 11, a plug 12, a faucet 13, an ultrasonic transmitter 14, a magnetic stirrer 15, a water inlet 16, a water outlet 17, and an ultrasonic transducer 6. The upper section 1 of the stirring drum is equipped with a multi-channel condenser tube 10, which is connected to the air outlet 11. A plug 12 is fitted at the air outlet, allowing the air outlet to be opened and closed as needed.

[0044] The stirring drum is placed on the base. The stirring drum includes an upper section 1 and a lower section 3, which are detachably connected by a connecting clamp 2. The upper section 1 forms a hollow sealed chamber. A multi-channel condenser tube 10 is arranged in the hollow sealed chamber. The multiple condenser tubes of the multi-channel condenser tube 10 are interconnected. The ends of at least two condenser tubes are connected to the inside of the stirring drum, and at least one condenser tube is connected to the outside of the upper section 1 through an air outlet 11. A plug is provided on the air outlet 11. The multi-channel condenser tube 10 and the inner wall of the stirring drum form a water-cooled chamber. The water-cooled chamber is provided with a water inlet 16 and a water outlet 17. The water inlet 16 is located below the water outlet 17.

[0045] To ensure the stable placement of the mixing drum, the bottom of the mixing drum is designed as a flat structure.

[0046] An ultrasonic transmitter 14 is installed inside the base 4, and the ultrasonic transmitter 14 abuts against the top plate of the base through an ultrasonic transducer 6. A heating plate 5 is installed above the top plate of the base. The heating plate is made of aluminum alloy and has a corrosion-resistant coating sprayed on its upper surface as a protective layer. The resistance wire is made of nickel-chromium alloy and has an aluminum oxide coating sprayed on its surface. A ceramic fiber board (heat resistant to about 1000℃) is installed at the bottom of the heating plate as a heat insulation layer. Figure 5 As shown.

[0047] A first annular flange is provided on the bottom outer wall of the upper section of the mixing drum, and a second annular flange is provided on the top outer wall of the lower section of the mixing drum. The first annular flange and the second annular flange are connected by a connecting clip 2. A sealing strip is provided at the connection between the upper section 1 and the lower section 3 of the mixing drum, and a faucet 13 is provided on the right side of the lower section of the mixing drum.

[0048] The connecting clip 2 can be a clip of various structures, as long as it can perform a clamping function. Alternatively, multiple clips can be distributed around the perimeter of the mixing cylinder for clamping. As one implementation method, for example... Figure 1 and Figure 4 As shown, the connecting clip is made of interlaced iron wires, and the clamping force generated by the iron wires provides the clamping effect.

[0049] It also includes a water tank 7, an outlet pipe 8, a return pipe and a water pump 9. The water tank 7 is placed on one side of the mixing drum. The water pump 9 is installed on the water tank 7 and connected to the inside of the water tank 7. The outlet of the water pump 9 is connected to the inlet of the water cooling chamber through the outlet pipe 8. The outlet of the water cooling chamber is connected to the inside of the water tank through the return pipe.

[0050] After the reaction, when cleaning the stirring tank, the liquid in the stirring tank can be directly drained by the water tap 13. The lower section 3 of the stirring tank is placed on the base 4, and a heating plate 5 is installed on the upper end of the base 4. An ultrasonic transmitter 14, an ultrasonic transducer 6, and a magnetic stirring motor 15 are placed at the bottom of the heating plate 5. The ultrasonic system operates at a frequency of 50-150 kHz, and its output power is adjustable in three levels: 300 W, 600 W, and 1200 W. The magnetic stirring motor is controlled by a switch, and its speed is adjustable within the range of 0-600 r / min. The heating temperature of the heating plate is adjustable within the range of 0-120 ℃.

[0051] The upper section 1 of the mixing drum is provided with an inlet 16 and an outlet 17. Both the inlet 16 and the outlet 17 are connected to the water pump 9 through water pipes 8. The water pump 9 is placed in the water tank 7. During the reaction, the water tank 7 should be filled with water first before the water pump is started.

[0052] A sol-gel modification method for ceramic powder specifically includes the following steps: 1) Raw material mixing stage: After mixing the proportioned metal alkoxide with the solvent, place it into a stirring tank, add a magnetic rotor, and seal and assemble the reaction device. The metal alkoxide can be aluminum isopropoxide, aluminum sec-butoxide, nitric acid, or sodium hydroxide, etc. 2) Sol formation stage: Simultaneously start ultrasound (50-150 kHz), magnetic stirring (0-600 rpm) and heating system (60-85℃) to promote the metal alkoxide to complete the transformation process of dissolution → hydrolysis. Sol formation is determined by Tyndall effect (usually takes 30-300 min).

[0053] 3) Gas regulation stage: Open the gas outlet to allow the reaction gas to pass through the multi-channel condenser, and most of the vapor is condensed and refluxed; excess gas is discharged in a directional manner; the system pressure is stabilized at 0.1-0.3 MPa.

[0054] 4) Powder coating stage: After the sol stabilizes, ceramic powder (particle size 0.5-5 μm) is added through the gas outlet, and a three-dimensional gel network is constructed on the powder surface through continuous polycondensation reaction.

[0055] 5) Post-processing stage: After stopping stirring and sonication, the temperature is gradually increased to 120℃ to dry the gel. After drying, the gel is removed from the stirring tank and the stirring tank is cleaned with ultrasonic waves. Finally, the densified ceramic material is obtained by sintering at 800-1200℃.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A sol-gel modification device for ceramic powder, characterized in that: Includes a mixing bowl and a base, wherein the mixing bowl is placed on the base, The mixing drum includes an upper section and a lower section, which are detachably connected by a connecting structure. The upper section of the stirring drum forms a hollow sealed chamber, in which a multi-channel condenser is installed. The multiple condensers of the multi-channel condenser are interconnected. The ends of at least two condensers are connected to the inside of the stirring drum, and at least one condenser is connected to the outside of the upper section of the stirring drum through an air outlet. A plug is installed on the air outlet. A water-cooled chamber is formed between the multi-channel condenser tube and the inner wall of the stirring drum. The water-cooled chamber is equipped with a water inlet and a water outlet. An ultrasonic transmitter is installed inside the base, and the ultrasonic transmitter abuts against the top plate of the base through an ultrasonic transducer. A heating plate is installed on the top plate of the base.

2. The sol-gel modification apparatus for ceramic powder according to claim 1, characterized in that: A first annular flange is provided on the bottom outer wall of the upper section of the stirring drum, and a second annular flange is provided on the top outer wall of the lower section of the stirring drum. The first annular flange and the second annular flange are engaged and fixed by a locking structure. Preferably, the shapes of the first annular flange and the second annular flange are adapted to the shape of the stirring cylinder; Preferably, a sealing strip is provided at the connection between the upper section and the lower section of the mixing drum.

3. The sol-gel modification apparatus for ceramic powder according to claim 1, characterized in that: A magnetic stirrer is installed inside the base.

4. The sol-gel modification apparatus for ceramic powder according to claim 1, characterized in that: A water tap is installed on the bottom side wall of the lower section of the mixing drum.

5. The sol-gel modification apparatus for ceramic powder according to claim 1, characterized in that: It also includes a water tank, an outlet pipe, a return pipe, and a water pump. The water pump is installed on the water tank and connected to the inside of the water tank. The water pump outlet is connected to the water inlet of the water-cooled chamber through the outlet pipe. The water outlet of the water-cooled chamber is connected to the inside of the water tank through the return pipe.

6. The sol-gel modification apparatus for ceramic powder according to claim 1, characterized in that: The water inlet of the water-cooled chamber is located below the water outlet.

7. The sol-gel modification apparatus for ceramic powder according to claim 1, characterized in that: The heating plate is made of aluminum alloy and has a corrosion-resistant coating sprayed on its upper surface as a protective layer. The resistance wire is made of nickel-chromium alloy and has an aluminum oxide coating sprayed on its surface. A ceramic fiber board is installed at the bottom of the heating plate as a heat insulation layer.

8. A sol-gel modification method for ceramic powder, characterized in that: Includes the following steps: After mixing the prepared metal alkoxide with the solvent, place the mixture in a stirring tank, add a magnetic rotor, and assemble the device. Simultaneous activation of ultrasonic and magnetic stirring and heating promotes the transformation of metal alkoxides from dissolution to hydrolysis, and the formation of sol is determined by the Tyndall effect; The gas outlet is opened to allow the reactant gas to pass through a multi-channel condenser, with most of the vapor being condensed and refluxed; excess gas is discharged in a directed manner; and the system pressure is stabilized at 0.1-0.3 MPa. After the sol stabilizes, ceramic powder is added through the gas outlet, and a three-dimensional gel network is constructed on the powder surface through continuous polycondensation reaction; Then, after stopping stirring and sonication, gradually increase the temperature to dry the gel.

9. The sol-gel modification method for ceramic powder according to claim 8, characterized in that: The raw materials include aluminum isopropoxide, aluminum sec-butoxide, nitric acid, or sodium hydroxide; the heating temperature is 60-85℃, and the temperature of the circulating condensate is 0-10℃.

10. The sol-gel modification method for ceramic powder according to claim 8, characterized in that: The ultrasonic transmitter operates at a frequency of 50-150 kHz and has a power of 300-1200 W. Preferably, the stirring speed of the magnetic stirrer is 0-600 r / min.

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