采用速度干涉(VISAR)测试技术,对强激光辐照下纯铝的动态力学响应和层裂特性进行了实验测量和分析.样品厚度分别为200 μm 和485 μm,激光脉冲的半高宽约为10 ns,功率密度变化范围为10¹⁰～10¹¹ W·cm^-2.实测了样品自由面速度波形,反映了强激光加载作用下材料损伤演化过程以及损伤对材料动态响应的影响.计算得到了冲击波强度(2.0～13.4 GPa) 和不同拉伸应变率下铝的层裂强度(1.6～2.3 GPa).在所采用的实验条件和1维近似下,激光辐照产生的冲击波强度与激光功率密度之间成线性关系.最后讨论了层裂强度与拉伸应变率之间的关系,显示层裂强度随着拉伸应变率的增加而增大.

The mechanical behavior and tensile spallation of pure aluminium subjected to intense laser irradiation were studied experimentally. The thicknesses of the samples are 200 μm and 485 μm, respectively.The laser irradiation intensity was in the range of 10¹⁰～10¹¹ W·cm^-2 with the full-width a half maximum of 10 ns. The free surface velocity of the shocked samples in the 242~1 125 m·s^-1 range was measured by push-pull VISAR (velocity interferometer system for any reflector), which contained lots of information about the damage evolution and the influence on the mechanical behavior. The ablation pressure obtained on the front surface of the targets was in the range of 2.0~13.4 GPa. Based on the experimental and one dimension strain conditions, the linear relationship between the ablation pressure and the laser intensity was obtained. A spall strength of 1.6~2.3 GPa in aluminium was measured at different tensile strain rate, and an apparent increase of spall strength with tensile strain rate was observed.