A Study on the Spallation Behavior of Silicon Nitride

Shock behavior of silicon nitride ceramic was investigated by using a onestage light gas gun facility. A new technique is developed to measure the spall characteristics of materials with embedded electro-magnetic particle velocity gauges in the sample. This method measures the particle velocity profiles inner the sample and particularly, the gauge located behind the spalling plane will disclose clearly the message of spallation of the sample, which differs from the usual methods such as VISAR and manganin gauge. By this method, we obtained experimentally the spall strength of silicon nitride ceramic of density 3.12 g/cm3 as 0.73 GPa, which fit the data of Nahme et al. The scab thickness was almost equal to the flyer thickness in the experiments, since the symmetry impact was used. The experimental results indicate that the particle velocity gauge method can be used to study the spllation behavior of non-electromagnetism materials. Since we used three gauges in one shot to record velocity profiles at different locations, so the Hugoniot data up to 3.6 GPa (as in elastic range) was also obtained.