抄録
Silicon carbide (SiC) powders with total 11 mass% of Y2O3 and SiO2 additives were sintered by hot-pressing at 1950oC for 1h under a pressure of 40 MPa in Ar flow or 1MPa Ar atmosphere. Bending strength, microstructure, oxygen content of the sintered specimens were evaluated. The sintered bodies achieved nearly full density in the wide range of additive composition in both cases. The dispersion of bending strength was remarkable in the case of Ar flow sintering.SEM micrographs revealed the difference in microstructure between inside and outside of sintered bodies. Oxygen content was also different between inside and outside of sintered bodies. These results suggest that volatilization of additives. After sintering under 1MPa atmospheric pressure, microstructural difference between outside and inside bodies was greatly reduced, and bending strength of sintered bodies showed constant values.
