High-energy ball milling of Al2O3-TiO2 powders

High-energy ball milling of Al2O3-13 wt% TiO2, and Al2O3-44 wt% TiO2 powders have been studied and more precisely the effect of the addition of a milling agent and the relative speed of the vials. The evolution of the microstructure of the milled powders has been studied by X-ray diffraction and the evolution of the specific surface areas has been determined. The pressure and the temperature inside the vials have been recorded. The milling of the powders induces the transformation of the anatase TiO2 phase into the high-pressure TiO2(II) phase and partly into the rutile TiO2 phase. A decrease in the corundum crystallite size is also evidenced. The addition of PVA as a milling agent in order to avoid severe agglomeration appears to be efficient to enhance the milling effect. The formation of the TiO2(II) phase can be controlled thanks to the vials speed and the milling time in order to obtain quite exclusively this high pressure TiO2 phase that could be interesting to manufacture nanostructured deposits. (C) 2006 Elsevier B.V. All rights reserved.