Patent ID: 6162386
Filing Date: 2000-12-19
Classification: C04B

Abstract:
A method for manufacturing a polycrystallline sintered body of between about 95-97 percent by volume .beta.-Si.sub.3 N.sub.4 with an oxygen content of about 1.2 to 1.5 percent by weight, said method comprising the steps of:adding an organic binder to a composition containing silicon nitride as an essential component and exhibiting a theoretical oxygen content of 2.0-2.3 wt. %;heating to remove the organic binder;introducing an oxygen-containing gas with an air flow rate of 3 to 60 L/min in a cooling step after removal of the organic binder so as to control the carbon content to 0.1-0.6 wt. %; andsintering the resultant compact in a nitrogen atmosphere to control the oxygen content to 1.2-1.5 wt. %.