Microstructure and mechanical properties of B₄C matrix composites sintered with (TiB₂+Al)

The B4C matrix composites were obtained with the addition of (24.5 % TiB2+2 % Al) using spark plasma sintering method at 1600 C with the pressure of 80 MPa for 5 min. Compared with the monolithic B4C ceramics, due to the (24.5 % TiB2+2 % Al) additive in B4C matrix composite, the densification temperature of B4C matrix composite was obviously decreased and the flexural strength was significantly improved. The B4C matrix composites exhibited the high flexural strength of 528 MPa, and a moderate Vickers hardness of 24.2 Gpa. The excellent flexural strength attributed to the second phases in the composites can prevent the cracks from extending and the energy disspation effect resulted from the intergranular fracture.