YANG Hao, LI Xiangcheng, DING Jun, YU Chao, DENG Chengji, ZHU Hongxi

(The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology,

Wuhan 430081, Hubei, China)

Abstract: Boron carbide is difficult to sinter and has low toughness. To address this problem, rare earth compounds, SiC, transition metal borides, carbon nanotubes, graphene and metal phase have been employed to increase mechanical properties of boron carbide ceramics, thus widening its application range as structural materials. Among the various additives, SiC and TiB2 are effective reinforcement phases of boron carbide ceramics, with strengthening and toughening mechanisms including particle toughening, solid solution enhancement and crack deflection and bridging due to the thermal expansion mismatch. The strengthening and toughening mechanisms will be discussed from the viewpoint of the mismatches of reinforcement phases and boron carbide, as well as the introduction method. In addition, the main direction of multi-diverse and multi-structural system design will discussed.

Key words: SiC; TiB2; carbide/boride compound; toughening