Preparation of MoSi₂ Based Composite and Its Strengthening and Toughening Mechanism

Several MoSi2 based composites were prepared by the vaccum hot pressure sintering technique. The influence of the strengthening and toughening phase on the microstructure and mechanical properties of the composites was studied, and the strengthening and toughening mechanisms were investigated. The results show that strengthening and toughening of the MoSi2 could be impoved inordinately by the strengthening and toughening phase addition. The effect depended on its amaunt, type and content, while two phases were appropriate. The micro-hardness, fracture toughness and flexural strength of the 5%/SiC+5%Nb/MoSi2 composites were 12.86 GPa, 1142 MPa·m1/2 and 470 MPa, compared with hot pressure sintering MoSi2 monomer composites increased by 3122%, 223.5% and 70.9% respectively. The strengthening and toughening mechanism of the multi-MoSi2 based composites was the synergy of the phases. The effects depended on the matching between the phases.