Method for synthesizing aluminum nitride and aluminum nitride-based composite material

Patent metadata

Field	Value
Publication number	US-10626017-B2
Application number	US-201616065131-A
Country	US
Kind code	B2
Filing date	Nov 29, 2016
Priority date	Dec 24, 2015
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

A method of synthesizing aluminum nitride, the method includes: preparing mixed powder containing 0.5 to 8 wt % of zinc powder, 0.01 to 2 wt % of magnesium powder, 0.01 to 1 wt % of silicon powder, 0.01 to 1 wt % of copper powder, and a balanced amount of aluminum powder; preparing a feedstock of the mixed powder blended and filled with thermoplastic organic binder, by pressured kneading the mixed powder and the thermoplastic organic binder; forming granules of the feedstock by crushing the feedstock or forming a molded body of the feedstock via a powder molding method; and debinding the granules or the molded body by heating under a nitrogen gas atmosphere, and then performing direct nitridation between aluminum and a nitrogen gas at a temperature higher than a debinding temperature.

First claim

The invention claimed is:

1. A method of synthesizing aluminum nitride, the method comprising:
preparing mixed powder containing 0.5 to 8 wt % of zinc powder, 0.01 to 2 wt % of magnesium powder, 0.01 to 1 wt % of silicon powder, 0.01 to 1 wt % of copper powder, and a balanced amount of aluminum powder;
preparing a feedstock of the mixed powder blended and filled with thermoplastic organic binder, by pressured kneading the mixed powder and the thermoplastic organic binder;
forming granules of the feedstock by crushing the feedstock or forming a molded body of the feedstock via a powder molding method; and
debinding the granules or the molded body by heating under a nitrogen gas atmosphere, and then performing direct nitridation between aluminum and a nitrogen gas at a temperature higher than a debinding temperature,
wherein the thermoplastic organic binder contains 80 to 95 wt % of a wax mixture and 20 to 5 wt % of polyolefin or modified polyolefin-based polymer,
wherein the feedstock contains the mixed powder and the thermoplastic organic binder at a volume ratio of 7:3 to 5:5.

2. The method of claim 1 , wherein an average diameter of the aluminum powder is 0.01 to 50 μm.

3. The method of claim 2 , wherein an average diameter of the aluminum powder is 0.1 to 20 μm.

4. The method of claim 1 , wherein an average diameter of the zinc powder, the magnesium powder, the silicon powder, and the copper powder is 0.1 to 50 μm.

5. The method of claim 4 , wherein an average diameter of the zinc powder, the magnesium powder, the silicon powder, and the copper powder is 0.5 to 30 μm.

6. The method of claim 1 , wherein the debinding is performed at a temperature of 420 to 540° C., and
the direct nitridation is performed at a temperature of 550 to 800° C.

7. The method of claim 1 , wherein the debinding and the direct nitridation are performed in one furnace using a single heating schedule.

8. The method of claim 1 , wherein a dew point of the nitrogen gas is −55° C. or lower, or a moisture content of the nitrogen gas is 0.002 vol % or less.

Assignees

• Univ Yeungnam Res Cooperation Foundation

Inventors

• Han Kwan Hee
• Kim Ju Hyun

Classifications

• C01B21/072 Primary

  with aluminium · CPC title

• B22F2201/02

  Nitrogen · CPC title

• C01P2004/03

  obtained by SEM · CPC title

• C01P2004/62

  Submicrometer sized, i.e. from 0.1-1 micrometer · CPC title

• B22F2304/058

  Particle size above 300 nm up to 1 micrometer · CPC title