The Effect of High-Energy Ball Milling on Sintering and the Mechanical Properties of Al2O3

The effect of high-energy ball milling on the sintering, microstructure and mechanical properties of Al2O3 were investigated. The temperature at the beginning of consolidation decreased with high-energy ball milling because the driving force for sintering and the contact points of the powders for atomic diffusion increased. The mechanical properties (hardness and fracture toughness) and the relative density of Al2O3 sintered from high-energy ball milled powder were higher than those of Al2O3 sintered from unmilled powder. Nanocrystalline materials have received much attention as advanced engineering materials with improved physical and mechanical properties. As nanomaterials possess high strength, high hardness, excellent ductility and toughness, undoubtedly, more attention has been paid to the application of nanomaterials. A highly dense nanostructured Al2O3 was produced using high-energy ball milled powder with simultaneous application of 80 MPa pressure and a pulsed output current of 2800 A within 2 min.