On the characterisation of the dynamic compressive behaviour of silicon carbides subjected to isentropic compression experiments

Abstract

Abstract. Ceramic materials are commonly used as protective materials particularly due to their very high hardness and compressive strength. However, the microstructure of a ceramic has a great influence on its compressive strength and on its ballistic efficiency. To study the influence of microstructural parameters on the dynamic compressive behaviour of silicon carbides, isentropic compression experiments have been performed on two silicon carbide grades using a high pulsed power generator called GEPI. Contrary to plate impact experiments, the use of the GEPI device and of the lagrangian analysis allows determining the whole loading path. The two SiC grades studied present different Hugoniot elastic limit (HEL) due to their different microstructures. For these materials, the experimental technique allowed evaluating the evolution of the equivalent stress during the dynamic compression. It has been observed that these two grades present a work hardening more or less pronounced after the HEL. The densification of the material seems to have more influence on the HEL than the grain size.

A pulse-shaping technique to investigate the behaviour of brittle materials subjected to plate-impact tests

“…The ceramic material considered in this investigation is silicon carbide (Hexoloy). This material was previously experimentally tested using shockless isentropic compression by means of the GEPI pulse power generator as discussed by Zinszner et al [28,9,29]. The first proposed experimental method is illustrated in figure 2a.…”

“…Ceramic materials can also be characterized using these generators. Indeed, Zinszner et al [28,29] have performed ICE on silicon carbides using the GEPI device and obtained longitudinal stresses in the ceramic material greater than 20 GPa. The same device was used by LaLone & Gupta [20] to characterize the elastic limit of x-cut quartz.…”