Dispersion of mechanochemically activated SiC and Al2O3 powders

Abstract

The mechanochemical milling is widely used as a top-down powder synthesis and preparation route. Coarse SiC and Al2O3 powders were ground with new high-energy mills running at 28 G for 30 min and 50 G for 5 min, respectively. The median particle size of SiC and Al2O3 was decreased from 500 to 1.46 mu m and from 6.4 to 1.81 mu m, respectively. Mechanochemically activated and agglomerated SiC and Al2O3 powders were dispersed using NH4 salt of polyacrylic acid in water. The median particle size of activated (or milled) Al2O3 and SiC powders was successfully reduced down to 0.72 and 0.48 mu m, respectively, by colloidal dispersion. The activated and dispersed Al2O3 powders also exhibited enhanced densification. (C) 2007 Elsevier B.V. All rights reserved.