Microstructure and properties of bilayered B4C-based ceramics

Bilayered B4C-based ceramics were obtained by hot-pressing. Microstructure, mechanical and ballistic properties of the bilayered ceramics were investigated. One layer was obtained upon addition of Ti and C to the hard B4C matrix, the newly formed TiB2 phase uniformly distributed in the matrix. The other layer included variable amounts of Ti3SiC2, equal to 10, 20, 30, 40 wt%, and the B4C-SiC matrix in a fixed weight ratio of 7:3. The amount of TiB2 and SiC phases, deriving from Ti3SiC2 decomposition upon sintering, increased with increasing the Ti3SiC2 content. The flexural strength and fracture toughness of bilayered ceramics both increased with increasing the Ti3SiC2 content from 10 to 40 wt%. Ballistic testing showed that the B4C-based ceramic target containing 30 wt% Ti3SiC2 broken into pieces upon being impacted by a 12.7 mm armor-piercing incendiary (API) projectile, and effectively consumed the bullet energy and protected the backing plate from serious damage.