Enhanced mechanical properties of a nanostructured Mg2Al4Si5O18–MgAl2O4 composite

Single-step synthesis and consolidation of nanostructured Mg2Al4Si5O18–MgAl2O4 composite were achieved via pulsed-current-activated heating using a mixture of 3MgO, 3Al2O3 and 5SiO2 powders. Before sintering, the powder mixture was high-energy ball milled for 10 h. From the milled powder mixture, a highly dense nanostructured Mg2Al4Si5O18–MgAl2O4 composite could be obtained within one minute by simultaneously applying 80 MPa of pressure and a pulsed current. The advantage of this process is that it allows simultaneous synthesis and densification to near theoretical density while sustaining the nanosized microstructure of raw powders. The mechanical properties (hardness and fracture toughness) of Mg2Al4Si5O18 were improved by the addition of MgAl2O4.