CN117431496A - A device and method for preparing aluminum nitride film on the surface of aluminum powder - Google Patents

Abstract

The invention discloses a device and method for preparing aluminum nitride thin films on the surface of aluminum powder, and belongs to the technical field of aluminum nitride thin film preparation. There is a vertical suspended air duct as a reaction chamber in the middle of the reactor lining; the reaction chamber spray gun is installed at the lower end of the suspended air duct to spray reaction gas for suspending reaction substances into the suspended air duct; the preheating tank is connected to the reaction chamber The spray gun is used to deliver heated reaction gas to the reaction chamber spray gun; the lift tank is connected to the preheating tank, used to increase the flow rate of the reaction gas flowing into the preheating tank; the gas source is connected to the lift tank, used to transport the reaction gas to the lift tank reaction gas. The present invention combines direct nitriding method and suspension method to achieve the preparation of aluminum nitride film on the surface of aluminum powder, which avoids the problem of melting agglomeration or agglomeration, does not require further ball milling and crushing, reduces the process flow, reduces production costs, and avoids The aluminum nitride film is damaged during the secondary processing ball milling process, which improves product quality.

Description

A device and method for preparing aluminum nitride film on the surface of aluminum powder

Technical field

The present invention relates to the technical field of preparation of aluminum nitride films, and in particular to a device and method for preparing aluminum nitride films on the surface of aluminum powder by direct nitridation.

Background technique

Aluminum nitride has good electrical insulation, wear resistance and corrosion resistance. The aluminum nitride film on the surface of aluminum powder can serve as a good protective film. Vapor deposition and magnetron sputtering are common methods for preparing aluminum nitride thin films. These methods are suitable for preparing high-precision thin films, but the production cost is high. Therefore, direct nitridation method is commonly used in industry to prepare aluminum nitride powder. This method uses aluminum powder and nitrogen or ammonia through a chemical reaction at high temperature.

When the existing direct nitriding method is used to prepare aluminum nitride powder, the reaction temperature needs to be between 800-1000°C, and the melting point of aluminum is about 650°C, so melt agglomeration and agglomeration will inevitably occur during the preparation process. , causing the nitrogen source atmosphere to be difficult to diffuse and the degree of nitridation to be low. Moreover, further crushing and ball milling are often required in the later stage. During the ball milling process, it will easily cause damage to the aluminum nitride film and introduce impurities into the system, reducing the quality of the aluminum nitride film.

Contents of the invention

The object of the present invention is to provide a device and method for preparing aluminum nitride thin films on the surface of aluminum powder to solve the problem of melt agglomeration or agglomeration that occurs when the existing direct nitridation method is used to prepare aluminum nitride thin films.

The present invention adopts the following technical solution: a device for preparing aluminum nitride thin films on the surface of aluminum powder, including:

The reactor lining has a vertical suspended air duct as a reaction chamber in the middle of the reactor lining;

Reaction chamber spray gun. The reaction chamber spray gun is installed at the lower end of the suspension air duct. The reaction chamber spray gun is used to spray reaction gas for suspending reaction substances into the suspension air duct;

The preheating tank is connected to the reaction chamber spray gun, and the preheating tank is used to deliver heated reaction gas to the reaction chamber spray gun;

The lifting tank is connected to the preheating tank, and the lifting tank is used to increase the flow rate of the reaction gas flowing into the preheating tank;

Gas source, the gas source is connected to the lifting tank, and the gas source is used to transport reaction gas to the lifting tank.

Preferably: the suspended air duct is cylindrical, has an outlet at the upper end of the suspended air duct, and an inlet at the lower end of the suspended air duct; the reaction chamber spray gun is installed at the inlet at the lower end of the suspended air duct; and a furnace door is installed at the outlet at the upper end of the suspended air duct. ; The furnace door is equipped with a feeding channel and an exhaust valve.

Preferably: the upper end of the suspended air duct has an enlarged section with a diameter larger than the diameter of the suspended air duct.

Preferably: the furnace door is connected to the flushing tank through a return pipe, a fifth valve is installed on one end of the return pipe close to the furnace door, and a sixth valve is installed on one end of the return pipe close to the lifting tank.

Preferably: the lifting tank is connected to the preheating tank through a first air inlet pipe, a first valve is installed on one end of the first air inlet pipe close to the lifting tank, and the first air inlet pipe is close to the preheating tank. A second valve is installed at one end;

The preheating tank is connected to the reaction chamber spray gun through a second air inlet pipe. A third valve is installed on one end of the second air inlet pipe close to the preheating tank. The second air inlet pipe is installed on one end close to the reaction chamber spray gun. There is a fourth valve.

Preferably: the reaction chamber spray gun has a tapered structure with a wide top and a narrow bottom. The upper surface of the reaction chamber spray gun has annular and evenly distributed air outlets. The upper surface of the reaction chamber spray gun is vertically opposite to the lower end inlet of the suspended air duct.

Preferably: a flow meter is installed at the air inlet of the reaction chamber spray gun; the reaction furnace lining 1 is connected to a thermometer for detecting the internal temperature of the reaction furnace lining 1 .

A method for preparing an aluminum nitride film on the surface of aluminum powder, including the following steps:

Step S1: Open the gas source, open the reactor lining, and adjust the flow rate of the reaction gas; add the powdery reaction material to the suspended air duct in the reactor lining, and the reaction material is suspended in the suspended air duct;

Step S2: Close the reactor lining and discharge the air in the reactor lining;

Step S3: Open the preheating tank and the reaction furnace; set the temperature of the preheating tank to 750-850°C, and set the temperature inside the reactor lining to 700-800°C; the reactant substances and reactant gases start to react, and the reaction time is set to 1- 2h;

Step S4: After the reaction is completed, close the preheating tank and the reaction furnace; when the temperature inside the reactor lining drops to room temperature, take out the product.

Preferably: the reaction material is aluminum powder, and the reaction gas is nitrogen.

Preferably: the suspended air duct in the reactor lining has a diameter of 0.1m and a length of 1.5m;

The diameter of the aluminum powder is 10±2 μm, the density of nitrogen at 2MPa is 15-16g/L, and the air outlet ratio of the reaction chamber spray gun is 3%.

The beneficial effects of the present invention are that the direct nitriding method and the suspension method are combined to achieve the preparation of aluminum nitride films on the surface of aluminum powder, thereby avoiding the problems of melting agglomeration or agglomeration that would occur with the conventional direct nitriding method. There are no agglomerates in the film, and there is no need for further ball milling, which reduces the process flow and production costs. It also avoids the damage of the aluminum nitride film during the secondary processing and ball milling process, and improves product quality.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a structural principle diagram of Embodiment 1 of the present invention.

Figure 2 is a front view of the reaction chamber spray gun in Embodiment 1 of the present invention.

Figure 3 is a side view of the reaction chamber spray gun in Embodiment 1 of the present invention.

Figure 4 is a top view of the reaction chamber spray gun in Embodiment 1 of the present invention.

Figure 5 is a flow chart of Embodiment 2 of the present invention.

In the picture: 1. Reaction furnace lining; 2. Suspended air duct; 3. Reaction chamber spray gun; 4. Return pipe; 5. Gas source; 6. Lifting tank; 7. Preheating tank; 8. Furnace door; 9. The first valve; 10, the second valve; 11, the third valve; 12, the fourth valve; 13, the exhaust valve; 14, the fifth valve; 15, the sixth valve.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "surroundings", etc. The indication of orientation or positional relationship is only to facilitate the description of the present invention and simplify the description. It does not indicate or imply that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. .

Embodiment 1

As shown in Figure 1, a device for preparing an aluminum nitride film on the surface of aluminum powder. A vertical suspended air duct 2 is provided in the middle of the reactor lining 1. The suspended air duct 2 is used for heating and heat preservation, and serves as a reaction chamber for reaction materials. and reaction gases provide space and temperature conditions. The reactor lining 1 is connected with a thermometer for detecting the internal temperature of the reactor lining 1 . The suspended air duct 2 is cylindrical, and the upper end of the suspended air duct 2 has an enlarged section with a diameter larger than the diameter of the suspended air duct 2 . The enlarged section is used to prevent the powdery reaction material from upwardly detaching from the suspended air duct 2 . The upper end of the suspended air duct 2 has an outlet, and the lower end of the suspended air duct 2 has an inlet. A furnace door 8 is installed at the upper outlet of the suspended air duct 2, and a feeding channel, an exhaust valve 13, and a return pipe 4 are installed on the furnace door 8.

The return pipeline 4 is connected to the flushing tank 6 , and the incompletely reacted gas in the suspended air duct 2 re-enters the flushing tank 6 through the return pipeline 4 . A fifth valve 14 is installed on one end of the return pipe 4 close to the furnace door 8 , and a sixth valve 15 is installed on one end of the return pipe 4 close to the flushing tank 6 . The gas source 5 is connected to the flushing tank 6 for transporting reaction gas to the flushing tank 6 . The gas source 5 may include multiple gas tanks such as gas A and gas B, and different reaction gases may be selected or reaction gases may be mixed.

The lifting tank 6 is connected to the preheating tank 7 through a first air inlet pipe. A first valve 9 is installed on one end of the first air inlet pipe close to the lifting tank 6. An end of the first air inlet pipe close to the preheating tank 7 is installed. A second valve 10 is installed. The flushing tank 6 is used to increase the flow rate of the reaction gas flowing into the preheating tank 7 and adjust the flow rate.

The preheating tank 7 is connected to the reaction chamber spray gun 3 through a second air inlet pipe. A third valve 11 is installed on the end of the second air inlet pipe close to the preheating tank 7. The second air inlet pipe has an end close to the reaction chamber spray gun 3. A fourth valve 12 is installed. The preheating tank 7 is used to heat the reaction gas, and then deliver the heated reaction gas to the reaction chamber spray gun 3 to make up for the heat loss in the gas path.

As shown in Figures 2 to 4, the reaction chamber spray gun 3 is installed at the lower inlet of the suspended air duct 2, and a flow meter is installed at the air inlet of the reaction chamber spray gun 3. The reaction chamber spray gun 3 has a tapered cylinder structure with a wide top and a narrow bottom. The sealing plate on the upper surface of the reaction chamber spray gun 3 has annular and evenly distributed air outlets. The upper surface of the reaction chamber spray gun 3 is vertically opposite to the lower end inlet of the suspended air duct 2 . The reaction chamber spray gun 3 is used to spray high-speed reaction gas into the suspension air duct 2. The air flow formed by the reaction gas in the suspension air duct 2 can suspend the powdery reaction material.

working principle:

This embodiment provides a device for preparing an aluminum nitride film on the surface of aluminum powder. By releasing gas at a certain flow rate, the aluminum powder and the melted aluminum powder are suspended in the reaction chamber, and complete the process in the suspended state. The nitrogen reaction generates aluminum nitride, which avoids adhesion and agglomeration between powders. It can not only increase the nitrogen content, but also avoid sintering and agglomeration.

Embodiment 2

On the basis of the above-mentioned Embodiment 1, combined with what is shown in Figure 5,

A method for preparing an aluminum nitride film on the surface of aluminum powder, including the following steps:

Step S1: Open the gas source 5, open the furnace door 8 of the reactor lining 1, open the first valve 9, the second valve 10, the third valve 11, and the fourth valve 12, adjust the flow meter, and control the flow rate of nitrogen to 3- 5L/min; add 100g of aluminum powder into the suspended air duct 2 in the reactor lining 1, and use nitrogen gas flow to suspend the aluminum powder in the suspended air duct 2 to avoid blocking the pores in the reaction chamber spray gun 3;

In this embodiment, the diameter of the suspended air duct 2 in the reactor lining 1 is 0.1m and the length is 1.5m; the diameter of the aluminum powder is 10±2μm (giving a reasonable range value), and the density of nitrogen at 2MPa is about 15-16g/L, (gives a reasonable range value), the diameter of the air outlet of the reaction chamber spray gun 3 is 2mm, evenly distributed at the spray gun mouth, the overall proportion is 3%, the specific distribution is shown in Figure 4 (small The hole can reduce the required flow rate as much as possible at a certain speed. If the proportion is too large, the demand for gas will be too large); the flow rate of nitrogen is calculated theoretically through an estimation formula and adjusted based on actual experimental phenomena;

Step S2: After the powder filling is completed, close the furnace door 8, open the exhaust valve 13, and discharge the air in the reactor lining 1; after 3 minutes, close the exhaust valve 13, open the fifth valve 14, and open the sixth valve 15, so that The unreacted gas flows back into the buffer tank;

Step S3: Open the preheating tank 7 and start the reaction furnace; the temperature of the preheating tank 7 is set to 750-850°C, and the temperature inside the reactor lining 1 is set to 700-800°C; the aluminum powder and nitrogen start to react, and the reaction time is set to 1-2h;

Step S4: After the reaction is completed, close the preheating tank 7 and close the reaction furnace; when the temperature inside the reactor lining 1 drops to room temperature, disassemble the reaction chamber spray gun 3 and take out the product to obtain aluminum powder coated with aluminum nitride film.

The invention provides a method for preparing aluminum nitride thin films on the surface of aluminum powder. The direct nitridation method and the suspension method are used to prepare the aluminum nitride thin film on the surface of the aluminum powder, which can well solve the sintering agglomeration caused by conventional preparation methods. The problem. In specific implementation, this method is not limited to the preparation of aluminum nitride films on the surface of aluminum powder. This method can be extended to cover other powders with aluminum films as a transition, and further realize the preparation of aluminum nitride on the surfaces of other powders through the aluminum nitride film. , and so on, without departing from the spirit of the present invention, structural methods and embodiments similar to the technical solution can be designed without creativity, and they shall all fall within the protection scope of the present invention.

The preferred embodiments of the invention disclosed above are only intended to help illustrate the invention. The preferred embodiments do not describe all details, nor do they limit the invention to the specific implementations described. Obviously, many modifications and variations are possible in light of the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can better understand and utilize the present invention. The invention is limited only by the claims and their full scope and equivalents.

Claims (10)

1. A device for preparing aluminum nitride thin films on the surface of aluminum powder, Its characteristics are: include, The reactor lining (1) has a vertical suspended air duct (2) serving as a reaction chamber in the middle; Reaction chamber spray gun (3), the reaction chamber spray gun (3) is installed at the lower end of the suspension air duct (2), and the reaction chamber spray gun (3) is used to spray reaction gas for suspending reaction substances into the suspension air duct (2); The preheating tank (7) is connected to the reaction chamber spray gun (3), and the preheating tank (7) is used to transport heated reaction gas to the reaction chamber spray gun (3); The lifting tank (6) is connected to the preheating tank (7), and the lifting tank (6) is used to increase the flow rate of the reaction gas flowing into the preheating tank (7); The gas source (5) is connected to the flushing tank (6), and the gas source (5) is used to transport reaction gas to the flushing tank (6). 2. A device for preparing aluminum nitride films on the surface of aluminum powder according to claim 1, characterized in that: the suspended air duct (2) is cylindrical, and the upper end of the suspended air duct (2) has an outlet, and the suspended air duct (2) has an outlet. The lower end of the duct (2) has an inlet; the reaction chamber spray gun (3) is installed at the lower inlet of the suspended air duct (2); the upper end outlet of the suspended air duct (2) is equipped with a furnace door (8); the furnace door ( 8) A feeding channel and an exhaust valve (13) are installed on it. 3. A device for preparing an aluminum nitride film on the surface of aluminum powder according to claim 2, characterized in that: the upper end of the suspended air duct (2) has an enlarged section with a diameter larger than the diameter of the suspended air duct (2). . 4. A device for preparing aluminum nitride film on the surface of aluminum powder according to claim 2, characterized in that: the furnace door (8) is connected to the flushing tank (6) through a return pipe (4), A fifth valve (14) is installed on one end of the return pipe (4) close to the furnace door (8), and a sixth valve (15) is installed on one end of the return pipe (4) close to the lifting tank (6). 5. A device for preparing aluminum nitride film on the surface of aluminum powder according to claim 1, characterized in that: the flushing tank (6) is connected to the preheating tank (7) through a first air inlet pipe , a first valve (9) is installed on one end of the first air inlet pipe close to the lifting tank (6), and a second valve (10) is installed on one end of the first air inlet pipe close to the preheating tank (7); The preheating tank (7) is connected to the reaction chamber spray gun (3) through a second air inlet pipe. A third valve (11) is installed on one end of the second air inlet pipe close to the preheating tank (7). A fourth valve (12) is installed at one end of the second air inlet pipe close to the reaction chamber spray gun (3). 6. A device for preparing aluminum nitride films on the surface of aluminum powder according to claim 1, characterized in that: the reaction chamber spray gun (3) has a tapered structure with a wide top and a narrow bottom. The upper surface has annular and evenly distributed air outlets, and the upper surface of the reaction chamber spray gun (3) is vertically opposite to the lower end inlet of the suspended air duct (2). 7. A device for preparing aluminum nitride films on the surface of aluminum powder according to claim 1, characterized in that: a flow meter is installed at the air inlet of the reaction chamber spray gun (3); the reaction furnace lining ( 1) A thermometer for detecting the internal temperature of the reactor lining (1) is connected. 8. A method for preparing an aluminum nitride film on the surface of aluminum powder, using a device for preparing an aluminum nitride film on the surface of aluminum powder according to any one of claims 1 to 7, characterized in that it includes the following steps: Step S1: Open the gas source (5), open the reaction furnace lining (1), and adjust the flow rate of the reaction gas; add powdery reaction material into the suspended air duct (2) in the reaction furnace lining (1). Suspended in the suspended air duct (2); Step S2: Close the reactor lining (1) and discharge the air in the reactor lining (1); Step S3: Open the preheating tank (7) and open the reaction furnace; the temperature of the preheating tank (7) is set to 750-850°C, and the temperature inside the reactor lining (1) is set to 700-800°C; the reaction materials and reaction gases Start the reaction and set the reaction time to 1-2h; Step S4: After the reaction is completed, close the preheating tank (7) and close the reaction furnace; when the temperature inside the reactor lining (1) drops to room temperature, take out the product. 9. A method for preparing an aluminum nitride film on the surface of aluminum powder according to claim 8, characterized in that: the reaction material is aluminum powder, and the reaction gas is nitrogen. 10. A method for preparing an aluminum nitride film on the surface of aluminum powder according to claim 9, characterized in that: the suspended air duct (2) in the reactor lining (1) has a diameter of 0.1m and a length of 1.5m; The diameter of the aluminum powder is 10±2 μm, the density of nitrogen at 2MPa is 15-16g/L, and the air outlet ratio of the reaction chamber spray gun (3) is 3%.