Quantitative analysis of de-aggregation behavior in alumina suspension by beads milling

The de-aggregation behavior of alumina powders with milling process was analyzed by precisely measuring the aggregates in dried suspension. This analysis was conducted under the condition that primary particles constituting aggregates were unbroken by milling operations. The measured distribution for the number of particles in each aggregate was compared with the simulated distribution based on the de-aggregation theory modified for this study. The change in measured distribution with milling times agreed well to the simulated one for relatively short milling times. The fractions of single particles measured experimentally were less than those in simulated results after prolonged milling. This is caused by the presence of strongly bonded twin or triplet particles which were difficult to separate into single ones. The present study clarified that it was important to remove the strongly bonded aggregates for preparation of mono-dispersed suspension by a conventional milling technique.