Synthesis method of silicon nitride powder and sintered body
AssigneeZone Infinity Co., Ltd.
InventorIn Chul Cho
Life of this patent
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Abstract
A synthesis method of silicon nitride powder including 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 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; and performing pressure sintering on a silicon nitride sintered body by filling the mixed powder into a mold and then keeping the mixed powder at a temperature of 1,750 to 1,850° C. for 2 to 6 hours while pressure of 150 to 300 kg/cm2 is applied thereto in a nitrogen gas atmosphere of 0.85 to 1 atm.
Claims12
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.
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 1,800 to 1,900° C. for 5 to 20 hours;
- and
- cooling the heat-treated mixed powder at −100° C./hr 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.
Dependencies are inferred from the claim text.