Abstract:To optimize the brittleness of transition metal silicides at low and medium temperature, the Co ₃Mo ₂Si reinforced and Co-based solid solution (Co _ss) toughened Co _ss/Co ₃Mo ₂Si composites were in-situsynthetised by hot pressing sintering, using metal powders as raw materials, and the microstructure and mechanical properties of Co _ss/Co ₃Mo ₂Si composites were studied. The results show that the Co _ss/Co ₃Mo ₂Si composites mainly consist of Co ₃Mo ₂Si ternary metal silicide phase and Coss phase in uniform distribution. With the increase of Co ₃Mo ₂Si ternary metal silicide phase weight fraction, the hardness increases but the bending strength decreases; with the increase of Coss phase weight fraction, the relative density and bending strength increase. The maximum bending strength can be increased from 335.7 MPa of Co ₃Mo ₂Si single phase to 756.2 MPa of Co _ss/Co ₃Mo ₂Si dual phases.