Microstructure and properties of Al203-TiO2 nanocomposite using high energy milling

This study has been conducted in order to improve several drawbacks in Al203 matrix composite such as lack in toughness, ductility and unstable to make useful for high temperature application. TiO2 is known to have excellent in chemical, mechanical stability and has good compatibility with Al203. The Al203- TiO2 nanocomposite was prepared using simple and inexpensive method, powder metallurgy. Elemental powders of alumina (Al203) and titania (TiO2) was milled in a planetary ball mill using 5 mm zirconia ball at 200, 250 and 300 rpm and 2, 4, 8, 10 h. Then, the composites powders were compacted using uniaxial single action hydraulic press in a cylindrical die at 400 MPa. The characterization involves are X-ray diffraction (XRD), scanning electron microscopy and density. The compressibility of as-milled composite powder was determined using Panelli-Ambrizio Filho equation. The XRD results showed that there is new phase exist at 300 rpm milling speed which later identified as AI2TiO5. Al2TiO5 exist during 2 and 4 h milling time and disappeared after 8 h milling time. Increasing milling time produced finer and flaky Al2O3-TiO2 as internal strain increase. The green density also increases as milling time and milling speed increase in which it enhances the plastic deformation.