Atmospheric pressure air plasma treated alumina powder for ceramic sintering

We report on plasma surface treatment of sub-micron alumina powder by the Diffuse Coplanar Surface Barrier Discharge (DCSBD) in ambient air. Even though the isoelectric point did not change after plasma treatment, the results indicated an enhanced colloidal stability of treated powder, especially when ultrasonication was used as homogenization method. Suspensions prepared from plasma treated powder also exhibit lower pH values compared to those of original powder. FTIR analysis confirmed enhanced sorption ability of treated powder. Polycrystalline alumina ceramics prepared from the treated powder possess significantly finer microstructure compared to those prepared from untreated powders. These findings may have a significant impact on ceramic engineering.