热处理工艺对纳米γ-氧化铝粉体性能的影响及优化

以异丙醇铝水解得到的水合氧化铝为原料,利用正交实验考察了焙烧条件(焙烧终点温度、升温速率、终点温度保温时间、277℃保温时间和590℃保温时间)对γ-氧化铝粉体性能的影响。结果表明:焙烧终点温度和升温速率对γ-氧化铝粉体性能的影响显著,终点温度主要影响氧化铝的结晶度、晶粒大小以及比表面积;升温速率则主要影响晶粒大小和粉体的团聚粒径。终点温度越高、升温速率越慢,晶体的晶粒越大,晶体发育趋于完整,比表面积下降,粉体的团聚现象得到明显改善。最佳工艺条件:焙烧终点温度为850℃,终点温度保温时间为30 min,升温速率为3℃/min,277℃和590℃均不保温。

Effect and optimization of heat treatment technology on properties of nano-sized y - Al2O3 powder

Hydrous alumina(Al2O3)was obtained from aluminum isopropoxide as raw material.Influences of factors including end point temperature,heating rate,and holding times at end point temperature,277 ℃ and 590 ℃ on the properties of γ-Al2O3 powder were investigated through orthogonal experiment.Results showed that the end point temperature and heating rate had a clear effect on properties of γ-Al2O3.Degree of crystallinity,grain size,and BET were mainly influenced by the end point temperature,and the heating rate had an effect on grain size,and agglomerated size.Higher the end point temperature and the slower the heating rate,the bigger particle size of crystal,the crystal would tend to be more integrity,BET decreasing,and the agglomeration of powders could be improved clearly.Optimum conditions was obtained as follows:the end point temperature was 850 ℃ and its holding time was 30 min,the heating rate was 3 ℃/min,and the holding times at 277 ℃ and 590 ℃ were both 0 min.