Abstract:

The densification and reaction sequence of 90wt%R-α' +10wt%12H (R=Y, Sm, Y+Sm) dual-phase ceramics hot-pressed in the temperature range of 1450~1800℃ were studied. The results show that the dual elements Y+Sm promote densification more effectively than Y-and Sin-element. In Sm-composition, Si₃N₄ disappears quickly and α-Sialon appears simultaneously with 12H--AIN--polytypoides. In Y--composition, however, Si₃N₄ dissolves slowly and 12H- AlN-polytypoid inhibits the formation of α-Sialon.

Key words: α -AlN-polytypoids dual-phase ceramics, rare earth elements, reaction sequence