In situ reactive spark plasma sintering of WSi2/MoSi2 composites

MoSi2 based materials have the potential for use in high temperature structural parts. In this work, WSi2 reinforced MoSi2 composites were successfully prepared by mechanical activation followed by in situ reactive spark plasma sintering of Mo, Si, and W elemental powders. Benefiting from the high energy raw materials prepared through ball milling, these mechanically activated reactants started to transform into MoSi2 at 1000 °C. Full density composites were obtained at a low sintering temperature (1200 °C) within 5 min. The addition of W to the reactants led to a finer microstructure than that obtained using pure MoSi2, resulting in a significant improvement of mechanical properties. The Vicker's hardness of 20 vol% WSi2/MoSi2 was as high as 16.47 GPa.