High Temperature Construction Materials on the Basis of Nanodisperse Silicon Nitride

Si 3 N 4 ‐Al 2 O 3 ‐Y 2 O 3 , Si 3 N 4 ‐TiN and Si 3 N 4 ‐AIN‐Al 2 O 3 ‐Y 2 O 3 (β‐sialon) nanopowders with the specific surface area of 60–70 m 2 /g and average particle size of 30–50 nm have been prepared by plasmachemical synthesis. By means of the hot pressing method at 1850°C compact materials with fine‐grained structure were prepared from this powders as well as from mixture of Si 3 N 4 ‐Al 2 O 3 ‐Y 2 O 3 with the second phase (10 wt.% SiC‐Si 3 N 4 , ZrO 2 , TiN nanopowder). Addition of the second phase to silicon nitride improves material strength.