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 TiB2B4C ceramic under different loading rates are summerized, fragmentation and comminution, featuring singlepeak 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.

Automated summary

This study investigated the failure behavior of TiB2-B4C ceramics under impact loading using SHPB testing and high-speed photography, identifying two different failure modes and proposing a new energy utilization ratio as an evaluation index. Additionally, a calculation method based on fractal theory was introduced to quantify the ceramic crushing process.