为实现准等熵压缩的波阻抗梯度飞片的实验研究

A study on generating quasi-isentropic compression via graded impedance flyer

采用粉末冶金方法 ,制备出波阻抗沿厚度方向呈特定分布的W Mo Ti体系梯度飞片 ,在二级轻气炮上进行了梯度飞片击靶实验的初步研究 .结果表明 ,利用梯度飞片可以实现对靶样品的准等熵压缩 ,击靶后产生的波阵面是平缓、连续上升的 ,明显不同于冲击压缩的陡峭波阵面 ,靶面压力峰值最高达到了 16 7GPa.

Quasi-isentropic compression techniques via graded impedance flyers allow investigations of material properties in a high-pressure, low-temperature regime which is inaccessible by conventional shock wave experiments. In the present study, quasi-isentropic experiments were performed on a two-stage light gas gun by using W-Mo-Ti system graded impedance flyers. The histories of the free surface velocity in targets were measured by VISAR. Effects of impedance distributions of the flyers on wave profiles were discussed mainly. It is found that the wave profiles with a smoothly-rising front were created and the maximum pressure peak reached 167GPa. The flyer with parabolic distribution of impedance can produce a better compressive wave profile.