Si₃N₄-BN非晶質複合粉体の相分離結晶化挙動に及ぼす加圧および焼結助剤の効果

抄録

Si₃N₄-BN nanocomposites are formed via phase separation and crystallization of amorphous Si₃N₄-BN composite powder during sintering. Amorphous Si₃N₄-BN composite powders were prepared by a vapor phase reaction method. To clarify the effect of applied pressure and sintering aid on the phase separation and crystallization behavior, the composite powders were hot-pressed and pressurelessly sintered with and without Y₂O₃-Al₂O₃ sintering aid. Si₃N₄ crystallized into α-phase at 1600°C without sintering aid, and into β-phase at 1400°C with sintering aid. It was found that the crystallization of Si₃N₄ and BN was promoted by applied pressure and sintering aid. On the other hand, the phase separation of BN from Si₃N₄ occurred around 1400°C regardless of applied pressure and sintering aid.