427 / 2019-03-01 10:38:49

Spallation Study of Cerium by Ultra-high Energy Laser Induced Shock Loading

Spall, Laser, Cerium

全体主题 > High Pressure Physics and Materials Science

High energy induced shock loading is an efficient method to study mechanical properties of materials under ultra-high pressure and ultra-high strain rate. By applying high energy pulsed laser ablation, we studied spallation of 250μm thick Ce targets under several hundred GPa. The spall took place thoroughly and the spallation fragments flied off the targets. The as-loaded Ce targets were then characterized by SEM, FIB, XRD, TEM. The thickness of the spallation is estimated to be 50-70μm. Moreover, Melting of Ce took place at the loading side of the targets during laser ablation process, and a rapid cooling process happened thereafter. The rapid cooling process evidently reduced the grain size to less than 1μm and can efficiently depress the further oxidization of Ce. The thickness of the rapid cooling layer is about 6±2μm. Spallation and rapid cooling behaviour of Ce under laser induced shock loading was studied for the first time. To get the spall strength and to study the phase transformations of Ce under laser induced shock loading, more spallation experiments of Ce with in-situ characterization techniques and less thick targets are to be carried out .