α-Al_2O_3纳米粉烧结初期的恒温实验研究

STUDY OF INITIAL STAGE SINTERING OF NANOCRYSTALLINE α-Al_2O_3 POWDER BY ISOTHERMAL METHOD

采用恒温烧结方式在900—1200℃范围内研究了粒径为10nm、团聚体强度分别为76和234MPa的α－Al2O3纳米粉初期烧结致密化过程．结果表明，两种粉体在烧结初期阶段均受品界扩散控制，其晶界扩散激活能分别为354和481kJ／mol，并对α－Al2O3纳米粉在实验温度范围内的晶界扩散系数进行了估算．

Isothermal sintering method was used to study the initial stage sintering of a soft and a hard agglomerated α-Al2O3 powder with a diameter of 10 nm. For both powders the initial stage sintering was found to be controlled by grain boundary diffusion. Activation energies of grain boundary diffusion of the soft and the hard agglomerated powders were determined to be 354 and 481 kJ/mol respectively and the diffusion coefficient of the soft agglomerated α-Al2O3powder from 900 to 1200 ℃ was estimated.