Dynamic failure behaviour analysis of TiB₂-B₄C ceramic composites by split Hopkinson pressure bar testing

As a novel composite ceramic, TiB₂-B₄C has been widely used in the lightweight protective armour due to its excellent physical properties such as high hardness, high fracture toughness, and low density. The failure behaviour of TiB₂-B₄C composite ceramics under impact loading is particularly important in the protective armour design. In the present paper, the split Hopkinson pressure bar (SHPB) testing of the TiB₂-B₄C ceramics is performed using the pulse shaping technique and high-speed photography. Two typical failure modes of the TiB₂-B₄C ceramic under different loading rates are summerized, fragmentation and comminution, featuring single-peak and double-peak waveform curves respectively. From the ceramic fragments collected after the impact, the failure process of TiB₂-B₄C ceramics during loading is analysed from an energy perspective. The results showed that the first impact of the incident bar has a more significant effect on TiB₂-B₄C ceramics, and the energy utilisation ratio of the specimen is an important index to determine the degree of failure. Moreover, a calculation method is proposed to quantify the crushing process of ceramics based on the fractal theory.