Rapid Sintering of Nanostractured (Mo,W)Si_2 and its Mechanical Properties

摘要

Nanocrystalline materials have received much attention as advanced engineering materials due to improved physical and mechanical properties. As nanomaterials undoubtedly possess high strength and hardness, as well as excellent ductility and toughness, more attention has been paid to the application of nanomaterials. Nanopowders of Mo, W and Si were made by high-energy ball milling. A dense nanos-tructured (W,Mo)Si_2 compound was sintered by the pulsed current activated combustion method within 2 minutes from mechanically activated powders of Mo, W and Si. A highly dense (Mo,W)Si_2 compound was produced under simultaneous application of a 80 MPa pressure and the pulsed current. Mechanical properties and microstructure were investigated. The hardness and fracture toughness of (Mo,W)Si_2 were 1242 kg/mm~2 and 4.3 MPa.m~(1/2), respectively. The mechanical properties were better than monolithic MoSi_2 or WSi_2.