论文部分内容阅读
研究了超声场下湿法制备纳米Al2 O3粉体的工艺 ,探讨了超声对颗粒的形成和团聚的影响 ,讨论了不同超声频率对粉体团聚的影响。研究表明 ,超声能量能加速前驱体的成核 ,超声分散可控制晶核的长大和团聚 ;超声振动还能影响陈化过程中的沉淀向凝胶的转变 ,并可适当增大凝胶孔径从而减小毛细管力 ,获得颗粒充分分散 ,而且不包含较多包藏水和牢固吸附水的疏松三维网络状结构。这样的凝胶结构有利于最后得到疏松、少 (无 )团聚的纳米粉体
The preparation process of nanosized Al 2 O 3 powders by ultrasonic method was studied. The effects of ultrasound on the formation and agglomeration of particles were discussed. The effects of different ultrasonic frequencies on the agglomeration of powders were discussed. The results show that the ultrasonic energy can accelerate the nucleation of the precursors, and the ultrasonic dispersion can control the growth and agglomeration of the nuclei. The ultrasonic vibration can also affect the transformation of the precipitates to gels during the aging process, and thus the gel pore size can be appropriately increased Reduce the capillary force and get the particles dispersed well, and does not contain more loose three-dimensional network structure that contains water and firmly adsorb water. This gel structure is conducive to finally get loose, less (no) agglomeration of nano-powder