Fabrication and Mechanical Properties of Nanostructured Al2O3-MgSiO3-SiO2 Composites Synthesized by Pulsed Current Activated Combustion of Mechanically Activated Powder

Abstract

Nanopowders of MgO, Al2O3 and SiO2 were made by high-energy ball milling. The fast sintering of nanostructured Al2O3-MgSiO3-SiO2 composites was investigated from mechanically activated powders of MgO, Al2O3 and SiO2 by a pulsed-current activated sintering process. Nanocrystalline materials have received much attention as advanced engineering materials with improved physical and mechanical properties; in particular greater strength, hardness, excellent ductility and toughness. Highly dense nanostructured Al2O3-MgSiO3-SiO2 composites were produced with simultaneous application of 80 MPa and pulsed output current of 2800A within 2 minutes. The sintering behavior, grain size and mechanical properties of Al2O3-MgSiO3-SiO2 composites were investigated.