Sintering of Si_3N_4 Ceramics in Air Atmosphere Furnace

摘要

Si_3N_4 ceramics with Y_2O_3 and Al_2O_3 additives set in an Al_2O_3 sagger with a Si_3N_4 powder bed were successfully sintered in air atmosphere furnace at 1600-1700 deg C.. Bulk densities of the sintered Si_3N_4 ceramics were 3.10-3.16 g/cm~3 which were similar to the densities of those sintered in a nitrogen gas furnace of 0.1 MPa. No heterogeneous surface layer was observed. When the sagger and powder bed are structured so that SiO gas continuously generated during the sintering, Si_3N_4 ceramics can be sintered in air without serious oxidation.