| 摘要 |
Sintered composite material, which is resistant to high temps., is based on the compsn. [SiC]x[Si3N4]1-x (I); in which x = 0.02-1.0; and also contains Y2O3 and/or lanthanide oxide(s), except CeO2 and La2O3, as sintering additive (II). The molar ratio of (II) to the oxygen content of (I), calculated as SiO2, is 0.5-1 and the vol. of sec. phase formed from (I) and (II) is 5-15 vol.%. Also claimed is the preparation of the composite in which a mixt. of the required amts. of SiC, Si3N4 and (II) is wet milled to particles sizes > 3 mu m, dried, moulded under pressure, sintered to >= 98.5% of the theoretical density under N2 and/or Ar and opt. CO and then cooled to 1500[deg]C at a rate of >= 10 K/min. |
