Abstract: A wet chemical method was adopted to introduce alumina sol to surface-modification of alumina bubble and in-situ decomposition characteristics, distribution of
alumina sol, microstructure and mechanical properties of surface-modified alumina bubble were studied by SEM, XRD, Coulter LS Particle Size Analyzer and self-preparation
experimental device for measurement of compressive resistance. The results showed that the alumina sol formed film on the surface, filtered into and distributed
on the pore and crack of alumina bubble. After heat-treatment at 500～900℃, the alumina sol can in-situ decompose to high active γ-Al₂O₃ powder,
compressive resistance of surface-modified alumina bubble was heightened from 15.6N to 30.2N after sintering at 1550℃.

Key words: alumina sol, alumina bubble, surface-modification