氮化硅陶瓷层裂强度的研究

 用一级轻气炮冲击加载装置，对氮化硅陶瓷进行了冲击性能实验研究。发展了一种新的方法用于研究层裂特性，即通过在样品中埋设电磁粒子速度计来记录氮化硅陶瓷内部的层裂特性。该方法不同于常用的VISAR激光干涉法和锰铜计法，记录的是样品内部粒子速度的变化特征，位于层裂面后方的粒子速度计能清晰地表征材料的层裂特性。通过实验，得到了密度为3.12 g/cm³的氮化硅陶瓷的层裂强度为0.73 GPa，和Nahme等得到的强度较为接近，对称碰撞得到的裂片厚度与该次实验的飞片厚度相当。实验表明，电磁粒子速度计的方法可以用于研究非磁屏蔽材料的层裂特性。由于采用多个计进行记录，还得到了材料在弹性区内（1.8~3.6 GPa）的Hugoniot冲击绝热线。

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.