The Formation of Alumina Ceramic Microspheres by Internal Gelation Process

Abstract

Alumina ceramic microspheres were prepared via internal gelation process. By dropping sol from a cold broth into hot silicone oil gelled microspheres would solidify within a few seconds by decomposition of hexamethylenetetramine (HMTA). The effect of the broth component on the performance of the broth and gelled microspheres obtained has been investigated. The Al2O3 ceramic microspheres can be obtained after aging, washing, drying and sintering. The Al2O3 microspheres prepared with optimized formulation have uniform size and good sphericity, with an average diameter of 690μm and crush strength of greater than 12N/sphere.