Hot-pressing of MoSi2 reinforced B4C composites

This paper reports on the effect of molybdenum disilicide (MoSi2) addition on the densification and mechanical properties of boron carbide (B4C). Molybdenum disilicide powder (10 and 30 wt%) was added to boron carbide powder and consolidated by hot pressing at various temperatures (1700–1900 °C) and pressures (30–50 MPa) in 0.001 Pa vacuum. MoSi2 was found to react with B4C and form reaction products SiC, MoB2 and Mo2B5. Slight improvement in density was observed with respect to MoSi2 addition. High density compact has been obtained with 30 wt% MoSi2 at 1900 °C under a pressure of 50 MPa. The hardness, elastic modulus and fracture toughness of high dense B4C+30 wt% MoSi2 compact was found to be 35.1 GPa, 555 GPa and 4.8 MPa m1/2 respectively.