ULTRASOUND EFFECTS ON VARIOUS OXIDES AND CERAMICS - MACROSCOPIC AND MICROSCOPIC ANALYSES

The sonochemistry of a heterogeneous medium such as a liquid/ solid po wder has been studied for various oxides (lead, manganese, aluminum, r are earth elements, silicon, titanium, and chromium) and ceramics (sup erconductor and titanium-yttrium compounds). The chemical transformati ons that occur during ultrasound treatments appear to differ from one material to another. The most important results relate the leaching of Pb3O4 which forms the dioxide in dilute acetic acid; and the formatio n of alpha-Al2O3, and Al(OH)(3) from the eta-Al2O3 form. It has been e stablished that ultrasound treatments decrease the grain size and smoo th small particles. (C) 1995 Academic Press, Inc.