Simultaneous Synthesis and Sintering of Nanostructured MgAl2O4-Mg3Al2Si3O12 Composite and its Mechanical Properties

Abstract

Nanopowders of MgO, Al2O3 and SiO2 were made by high energy ball milling. The simultaneous synthesis and consolidation of nanostuctured MgAl2O4-Mg3Al2Si3O12 composites from milled 4MgO, 2Al(2)O(3) and 3SiO(2) powders was investigated by a high-frequency induction heating process. The advantage of this process is that it allows very quick densification to near theoretical density and inhibition of grain growth. Highly dense nanostructured MgAl2O4-Mg3Al2Si3O12 composites were produced with a simultaneous application of 80 MPa pressure and an induced current within 1 min. The relative density and fracture toughness of the composite were 98% and 3.2 MPam(1/2), respectively. The fracture toughness of the MgAl2O4-Mg3Al2Si3O12 composite was higher than that of monolithic MgAl2O4.