| 摘要 |
PURPOSE:To produce a silicon nitride sintered compact having a sufficient strength and durability as a structural material used at about 1500 deg.C at the maximum, on the other hand, a relatively high strength even at ambient temperature. CONSTITUTION:This silicon nitride sintered compact comprises silicon nitride grains and a grain boundary containing R (R is a rare earth element), Si, O and N. In the sintered compact, a melilite phase (R2Si3N4O3) is present only in the surface layer part. |
