Effect of MoO3 on microstructure and mechanical properties of (Ti,Mo)Al/Al2O3 composites by in situ reactive hot pressing

(Ti,Mo)Al/Al2O3 composites were successfully synthesized by hot pressing based on the Ti–Al–TiO2–MoO3 system. Effect of MoO3 content on the microstructure and mechanical properties of (Ti,Mo)Al/Al2O3 composites was investigated in detail. It was found that the as-fabricated samples contain TiAl, Ti3Al, and Al2O3, together with a small amount of Ti2AlMo phase reinforcement phase. The fine Al2O3 particles dispersed on the TiAl matrix grain boundaries as a network structure and resulted in the improvement of room mechanical properties of the composites. With increasing of MoO3 contents, the flexural strength and fracture toughness of (Ti,Mo)Al/Al2O3 composites gradually increase, and with 1.0 at% MoO3, doped the products possess the maximum value of 702 MPa and 8.3 MPa m1/2 for the flexural strength and fracture toughness, respectively.