Effect of Rare Earth Elements on Formation Kinetics of α'-AlN-Polytypoids Dual-Phase Ceramics

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.