反向碰撞法测量Bi的低压Hugoniot数据

在火炮和二级轻气炮上利用反向碰撞技术,通过测量飞片击靶速度以及飞片/窗口的界面粒子速度,获得了金属铋(Bi)在10-45 GPa压力范围内的Hugoniot数据. 该方法克服了电探针法在测量低压Hugoniot数据时由于导通一致性差而不能准确得到冲击波速度的难题,同时又避免了精确测量样品中冲击波走时的问题. 实验获得的冲击波速度(D)-波后粒子速度(u)Hugoniot数据表明,Bi在粒子速度u=0.9 km/s附近D-u曲线发生了明显拐折,产生这一拐折的原因推测与冲击导致的Bi的固-液相变有关. 关键词： Hugoniot数据 反向碰撞 冲击相变 铋

Measurement of low-pressure Hugoniot data for bismuth with reverse-impact geometry

Hugoniot data for Bi are determined through measuring the impact velocity and the particle velocity at the sample/window interface on a powder gun or a two-stage light gas gun in a shock pressure range from 10 to 45 GPa, using reverse-impact geometry. The used experimental technique avoids the difficulty in accurately measuring the shock wave velocity resulting from the poor start synchronigm of electric pins under low shock pressure. The obtained Hugoniot data (shock wave velocity D versus particle velocity u) indicates that the D-u curve does have a discontinuity at a particle velocity of ~0.9 km/s, which is likely to be caused by the shock-induced solid-liquid phase transformation.