Investigation of structures and properties of oxide-hydroxide systems after mechanical activation

It has been studied Al₂O₃ and ZrO₂ with Al(OH)₃mixtures after mechanical activation in a planetary ball mill.Measurement of the specific surface by the BET method has shown that an increase of mechanical treatment time leads to an increase in the specific surface in all studied powders. In the initial states a large agglomerate of the order of 50-150 μm and isolated particles of 0.05-0.1 μm were observed. Mechanical treatment leads to fracture of agglomerates into separate particles. It has been revealed that the amount of agglomerates decreased with the increasing of the mechanical activation time, and the number of isolated particles increased. The average size of the agglomerates of Al-based powders varies in the range of 50-15 μm. In the case of powders based on ZrO₂, it varies in the range of 10-14 μm. (paper)