Dynamic response of the TiB2–SiC/B4C composite ceramic under dynamic loading

Abstract

AbstractTiB2–SiC/B4C composite ceramics have application as lightweight armor ceramic material, and therefore, it is particularly important to research their dynamic mechanical properties and fracture behavior under high strain rates. In the present research, the dynamic compression strength and Hugoniot elastic limit (HEL) of these composite ceramics were determined by split Hopkinson pressure bar technology and plate impact equipment, respectively. The experimental investigation results illustrated that the composite ceramic exhibited outstanding dynamic compression strength (2750 MPa) and displayed a remarkable strain‐rate strengthening effect. The HEL was calculated as 18.49 GPa, and the commonly used P–μ form of the Hugoniot curve was derived from the calculated data of the shock velocity and particle velocity. The dynamic fracture morphologies of the TiB2–SiC/B4C composite ceramic and monolithic B4C ceramic (correlation data) at macro and micro scales were observed and analyzed in detail. The dynamic fracture mechanisms were summarized in‐depth into the following three points. First, the strengthening mechanism offered by the in situ second phases could significantly improve the comprehensive property. Second, the mixed‐inter/transgranular fracture mode was conducive to energy absorption. Third, the anchoring effect and thermal expansion coefficient mismatch contributed to the energy dissipation and fracture toughness improvement. This work provides the foundation for the application and development of lightweight armor ceramic materials.