CN-116675189-B - Method for synthesizing aluminum nitride by utilizing microgravity combustion

Abstract

The invention discloses a method for synthesizing aluminum nitride by utilizing microgravity combustion, which uses Mg 4 Al 3 or Mg 17 Al 12 powder as a raw material, burns in a microgravity and nitrogen atmosphere, and purifies combustion products by using hydrochloric acid to obtain AlN powder. The method is suitable for small-particle (particle size 1 μm) raw materials and large-particle (particle size 500 μm) raw materials, and has the advantages of short synthesis time consumption, high purity of the obtained aluminum nitride, and capability of maintaining the temperature of a synthesis chamber and reducing energy consumption by using heat generated by combustion.

Inventors

• XIE XIAO
• ZHANG YAN
• CHEN CHAO
• LI HAIJIAN
• XU YI
• QIN ZHAO
• SUN ZHIHUA
• YI JIANHUA
• ZHAO FENGQI

Assignees

• 西安近代化学研究所

Dates

Publication Date

20260505

Application Date

20230619

Claims (9)

1. 1. A method for synthesizing aluminum nitride by utilizing microgravity combustion, which is characterized by comprising the following steps: step 1, raising the temperature of a synthesis chamber to above 900 ℃ and maintaining; Step 2, introducing nitrogen into the synthesis chamber to purge so as to discharge original air in the synthesis chamber; step 3, regulating the pressure in the synthesis chamber; Step 4, feeding Mg 17 Al 12 powder or Mg 4 Al 3 powder into the synthesis chamber from the upper part of the synthesis chamber, igniting the powder and falling through free falling; step 5, regulating the mass flow rate of nitrogen; step 6, cooling after the reaction is completed, and taking out a synthesized product after the temperature reaches the room temperature; Step 7, pouring the synthetic product obtained in the step 6 into dilute hydrochloric acid for dissolution; Step 8, filtering after no bubbles are generated in the dissolving process of the step 7, and cleaning the filtered matter with distilled water for 2-3 times; and 9, drying the product obtained in the step 8 in a drying oven, and obtaining high-purity aluminum nitride powder after drying.
2. 2. The method for synthesizing aluminum nitride by microgravity combustion according to claim 1 wherein the synthesis chamber has a height of not less than 1m and a diameter of not less than 50cm.
3. 3. The method for synthesizing aluminum nitride by microgravity combustion according to claim 1 wherein the particles of Mg 17 Al 12 powder and Mg 4 Al 3 powder are nearly spherical and have a particle size of 1 to 500 μm.
4. 4. The method for synthesizing aluminum nitride by micro gravity combustion according to claim 1, wherein in the step 3, the pressure in the synthesizing chamber is adjusted to 1-1.2 atm.
5. 5. The method for synthesizing aluminum nitride by micro gravity combustion according to claim 1, wherein in the step 5, the nitrogen mass flow rate is 0.6-2 times of the powder mass flow rate.
6. 6. The method for synthesizing aluminum nitride by micro gravity combustion according to claim 1, wherein in the step 7, not less than 1.67g of hydrochloric acid is required for dissolution per gram of Mg 4 Al 3 .
7. 7. The method for synthesizing aluminum nitride by micro gravity combustion according to claim 1, wherein in the step 7, not less than 1.71g of hydrochloric acid is required for dissolution per gram of Mg 17 Al 12 .
8. 8. The method for synthesizing aluminum nitride by micro gravity combustion according to claim 1, wherein in the step 9, the temperature of the drying oven is 50-100 ℃.
9. 9. The method for synthesizing aluminum nitride by micro gravity combustion according to claim 1, wherein in the step 9, the drying time is 1-3 hours.

Description

Method for synthesizing aluminum nitride by utilizing microgravity combustion Technical Field The invention belongs to the technical field of material science, and relates to a method for synthesizing aluminum nitride by utilizing microgravity combustion. Background In recent years, synthesis and utilization of AlN have attracted increasing attention due to its superior properties, for example, alN has been used as a packaging material for electronic devices due to its characteristics of high thermal conductivity, low dielectric constant and high resistivity, and AlN has been used for radio frequency filters and has been widely used for mobile phones due to its piezoelectric characteristics. At present, two different modes are mainly adopted for AlN synthesis, namely a carbothermal reduction method and an aluminum direct nitriding method, in the two methods, the nitriding experiment is carried out at high temperature due to the fact that the melting point and the boiling point of Al are high, and high pressure and long reaction time are needed for obtaining high-purity AlN due to the fact that the generated AlN is easy to agglomerate. Therefore, there is increasing interest in developing a simple and economical method for preparing AlN. In recent years, combustion synthesis has been one of the most efficient and promising methods for producing aluminum nitride. Compared with the carbothermic method and the direct nitriding method, the combustion synthesis method can produce high-purity AlN in a short time by utilizing the heat released by self-diffusion combustion of the sample. However, in the current combustion synthesis method, simple substance aluminum, aluminum salt and the like are still used as raw materials, and precipitation and agglomeration of AlN in the synthesis process prevent N 2 from penetrating into Al particles, so that sample nitridation is incomplete. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a method for synthesizing aluminum nitride by utilizing microgravity combustion, which is a simple, economical and efficient aluminum nitride synthesis method, can reduce the temperature required by aluminum nitride synthesis, shorten the synthesis time, reduce the emission of pollutant gas and is easy to realize industrialization. In order to solve the technical problems, the invention adopts the following technical scheme: a method for synthesizing aluminum nitride by utilizing microgravity combustion, comprising the following steps: step 1, raising the temperature of a synthesis chamber to above 900 ℃ and maintaining; Step 2, introducing nitrogen into the synthesis chamber to purge so as to discharge original air in the synthesis chamber; step 3, regulating the pressure in the synthesis chamber; Step 4, feeding Mg 17Al12 powder or Mg 4Al3 powder into the synthesis chamber from the upper part of the synthesis chamber, igniting the powder and falling through free falling; step 5, regulating the mass flow rate of nitrogen; step 6, cooling after the reaction is completed, and taking out a synthesized product after the temperature reaches the room temperature; Step 7, pouring the synthetic product obtained in the step 6 into dilute hydrochloric acid for dissolution; Step 8, filtering after no bubbles are generated in the dissolving process of the step 7, and cleaning the filtered matter with distilled water for 2-3 times; and 9, drying the product obtained in the step 8 in a drying oven, and obtaining high-purity aluminum nitride powder after drying. The invention also comprises the following technical characteristics: specifically, the height of the synthesis chamber is not less than 1m, and the diameter is not less than 50cm. Specifically, the particles of the Mg 17Al12 powder and the Mg 4Al3 powder are nearly spherical, and the particle size is 1-500 mu m. Specifically, in the step 3, the pressure in the synthesis chamber is adjusted to be 1-1.2 atmospheres. Specifically, in the step 5, the nitrogen mass flow rate is 0.6-2 times of the powder mass flow rate. Specifically, in the step 7, not less than 1.67g of hydrochloric acid is required to be dissolved per gram of Mg 4Al3. Specifically, in the step 7, not less than 1.71g of hydrochloric acid is required to be dissolved per gram of Mg 17Al12. Specifically, in the step 9, the temperature of the drying oven is 50-100 ℃. Specifically, in the step 9, the drying time is 1-3 hours. Compared with the prior art, the invention has the following technical effects: according to the invention, on one hand, the shell layer of aluminum nitride is broken by utilizing the vapor diffusion of magnesium in the raw material, the nitriding rate of aluminum is improved, the time required by nitriding synthesis is reduced, and on the other hand, the temperature required by synthesis is maintained by utilizing the energy generated by raw material combustion, so that the energy consumption is reduced. In additio