Abstract
In order to study the yielding property etc. under shock compression of the Si3N4 ceramics, the Hugoniot curve measuring experiments were performed in the pressure range up to 35GPa. Two different kinds of sintered specimen (the normal and fine sintered ones) were used to examine the effect of fine structure on the yielding property. The Hugoniot parameters were measured by the inclined-mirror method combined with the keyed-powder gun. The Hugoniot-elastic limit (HEL) stresses of the normal and fine sintered ones were determined to be 10.2-15.5 and 15.0-22.0GPa, respectively, and both Hugoniot compression curves converge each other in the plastic region. As a result, it was found that, although these Si3N4 ceramics behave as elastoplastic solids under shock compression, the Hugoniot-elastic limits are strongly influenced by its fine structure.
