Effects of high energy ball milling on ceramic oxides

High energy milling using a planetary apparatus was applied to various ceramic materials. Mechanical alloying allows in particular to obtain nanocrystalline and amorphous oxides. For instance, the room temperature synthesis of stabilized zirconia and the preparation of amorphous phases in the Al2O3-ZrO2-SiO2 system were recently reported. Nanocrytalline metastable phases (High pressure and/or High temperature phases) induced by phase transitions are also obtained. The structure of these various nanocrystalline and amorphous oxides prepared by high energy ball-milling is compared to that of the crystalline oxides. Studies by transmission electron microscopy and EXAFS reveal disorder effects induced by the mechanical process.