冲击压缩下氧化铝陶瓷中的延迟破坏实验研究

A study on a delayed failure of alumina under impact compression

利用轻气炮对不同厚度的氧化铝陶瓷试件进行了平板冲击实验,并借助激光速度干涉仪(VISAR)测试了试件的自由面速度历程。实验结果显示,自由面速度曲线上存在表征破坏波出现的二次压缩信号。根据实验结果计算获得了破坏波穿过试件的运动进程,并确定了试件中破坏波的运动轨迹近似为一条直线,得出在冲击压力为7.16GPa时试件内破坏波波速约为5.051km/s,破坏延迟时间约为0.105μs。最后简单分析了该现象产生的物理机制。

A series of plate impact experiment with alumina specimens in different thicknesses were conducted on a gas gun in order to further investigate the delayed failure phenomenon under shock loading.With the aid of the VISAR technique,a evident recompression signal was observed in the history of rear free surface of specimen,which indicates the generation of the failure wave.According to the experimental results,the failure wave trajectory was explored.The results show that the failure wave is generated with a delayed time of about 0.105μs behind the shock wave front,and propagates into the stressed body with a velocity about 5.051km/s under the impact stress of 7.16GPa.The physical mechanism of this phenomenon is discussed in the end.