在一级轻气炮上,利用光透射测量技术观测了石英玻璃在冲击(低于它的Hunoniot弹性极限)以及冲击后再卸载过程中的透射率随时间变化特征.发现石英玻璃在1·8GPa附近的冲击条件下,1·5μs内保持了良好的透明性.但处于压缩透明状态的石英玻璃在卸载波的作用下其透明状态仅维持约0·7μs,透射率在随后的0·8μs内下降了约30%.这一现象是由石英玻璃在卸载波的作用下发生损伤所致.透光性的时间效应与玻璃中局部损伤及演化特性密切相关,球状粒子的生长和散射模型对这一现象给出了合理解释.对Dolan等人[J.Chem.Phys.1219050]提出的水冲击晶化解释提出质疑.本文结论对冲击实验中其他窗口材料的透明性研究具有重要的参考价值.
Optical transmission of quartz glass is measured during loading and unloading process,and the stress was kept below their Hugoniot elastic limit. The results show that the quartz glass maintains good transparency for more than 1.5μs under loading processes of 1.8 GPa,then it starts to lose its transparency about 0.7μs after unloading,with 30% decrease of transmittance. This phenomenon,which reflects the growth and evolution of failure induced by unloading process in quartz glass,has been explained reasonably by the growth of spherical particles and the scattering model. The results are different from the explanation of liquid-solid phase transition given in literature [J. Chem. Phys. 2004, 121 9050]. This paper is significant for studying the transparency of other transparent material.