Evolution of shock waves in hot-pressed ceramics of boron carbide and silicon carbide

In this paper we studied the evolution of shock compression waves in hot-pressed ceramics based on boron carbide and silicon carbide at a maximum compressive stress of 32 and 34 GPa, respectively, to determine the possible contribution of relaxation processes to the resistance to high-rate deformation. At a change in sample thickness from 0.5 to 8 mm, an appreciable decay of the elastic precursor was observed in boron carbide while an insignificant anomalous growth of the elastic precursor with a sample thickness was observed in the experiments with silicon carbide samples of various thickness. The measured value of the Hugoniot elastic limit of samples with a thickness of 8 mm was $\sigma_{\operatorname{HEL}}$ = 17.2 $\pm$ 1.3 GPa for boron carbide and $\sigma_{\operatorname{HEL}}$ = 17.2 $\pm$ 0.1 GPa for silicon carbide.