Planar shock compression of spark plasma sintered B4C and B4C–TiB2 ceramic composites

Abstract

Blending of ceramic constituent phases enhances sinterability and performance in high strength ceramics. Here, a near fully dense blended boron carbide (B4C)–titanium diboride (TiB2) composite produced through spark plasma sintering (SPS) is probed to understand the mechanical performance under dynamic uniaxial strain, or shock compression. This study on the shock performance of blended B4C–TiB2 measures the effect of initial TiB2 powder size on the dynamic response of the composite and compares results to those of monolithic SPS B4C. These shock experiments reveal a strengthening of the Hugoniot elastic limit (HEL) with an addition of TiB2 and mitigation of the adverse post-HEL response observed in many brittle ceramics, such as monolithic B4C. The TiB2 particle size in the composite does not noticeably influence these results. The tough nature of TiB2 along with compressive residual stresses in the B4C matrix resulting from high temperature processing and a mismatch of the thermal expansion coefficients of the constituent phases are postulated to strengthen the B4C.