US 12,486,170 B2
Synthesis method of silicon nitride powder and sintered body
In Chul Cho, Gyeonggi-do (KR)
Assigned to ZONE INFINITY CO., LTD., Gyeonggi-do (KR)
Filed by ZONE INFINITY CO., LTD., Gyeonggi-do (KR)
Filed on Dec. 13, 2022, as Appl. No. 18/080,016.
Claims priority of application No. 10-2021-0189291 (KR), filed on Dec. 28, 2021.
Prior Publication US 2023/0339755 A1, Oct. 26, 2023
Int. Cl. C01B 21/068 (2006.01); C04B 35/593 (2006.01)
CPC C01B 21/0682 (2013.01) [C01P 2004/03 (2013.01); C01P 2004/61 (2013.01); C04B 35/593 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A synthesis method of silicon nitride powder, comprising:
preparing mixed powder having a particle size of 8 to 10 μm which includes 69 to 98 wt % of silicon powder, 1 to 30 wt % of α-phase silicon nitride powder, and 1 to 10 wt % of silicon dioxide powder;
performing heat treatment on the mixed powder in a synthesis electric furnace under a nitrogen gas atmosphere of 0.85 to 1 atm at a temperature of 1,450 to 1,750° C. for 5 to 20 hours; and
cooling the mixed powder gradually to obtain silicon nitride powder,
wherein, before the performing of heat treatment, first mixed gas obtained by mixing nitrogen gas and hydrogen gas is fed into the synthesis electric furnace at a temperature of 600° C., and second mixed gas obtained by mixing moisture, nitrogen gas, hydrogen gas, and hydrogen fluoride gas is fed into the synthesis electric furnace at a temperature of 1,000° C., and
wherein, after the performing of heat treatment, feeding of the first mixed gas and the second mixed gas is stopped.