低孔隙度疏松铝的高压声速与冲击熔化

对含微孔洞疏松度m=1.04的疏松铝进行了冲击加载-卸载实验,利用DISAR(distance interferometer system for any reflector)测得了53至99 GPa五个冲击压力下疏松铝/LiF界面粒子速度波剖面,获得了各压力下的纵波声速和其中三个压力点的体波声速,确定出疏松铝的冲击熔化压力约为81 GPa,确定出高压下冲击熔化前的泊松比约为0.372.通过分析,微孔洞明显降低了冲击熔化压力,引起的非谐振效应明显,状态方程计算中考虑非谐效应,非谐因子l 关键词： 低孔隙度 疏松铝 声速 冲击熔化

Sound velocity and shock melting of low porosity aluminum

Shock loading-release is performed on the porous aluminum with micropore and porosity m=1.04. Time-resolved interfacial velocity between the porous aluminum and LiF window is measured with diatance interferometer system for any reflector (DISAR) under five pressures ranging from 53 GPa to 99 GPa . From the interfacial velocity, the Euler longitudinal sound velocities under five pressures and the bulk sound velocities under 53 GPa, 72 GPa and 91 GPa are obtained. The melting pressure of the material is about 81 GPa. The poisson ratio before shock melting is about 0.37. From the analysis, the existence of the micropore in the material reduces the the shock melting obviously. So, its induced anharmonic effect cannot be neglected. Considering anharmonic effect into the equation of state, the anharmonic parameter is calculated to be about 30.