飞秒激光辐照铝材料的分子动力学数值模拟

Molecular dynamics simulation of radiation effects in Al foilirradiated by femtosecond laser beams

采用大尺度分子动力学方法对飞秒激光辐照金属铝材料的效应进行了数值模拟。利用分子动力学方法给出了飞秒激光辐照后,材料表面发生熔化和喷溅,冷凝后形成一层很薄的多孔介质的物理图像,及产生的应力波传播过程等。数值模拟结果表明分子动力学方法可以用于飞秒激光对材料辐照效应的研究。

A large scale molecular dynamics(MD) method has been employed to reveal the atomistic information of the femtosecond laser ablation of an Al foil surface. A 12.15nm×12.15nm×81nm supercell involving more than 700,000 atoms is arranged to simulate the ablation process in the center area of the foil. According to the simulation an ablation stress wave of magnitude 8GPa results in the foil irradiated with laser energy 11943J/m^2. The simulation results show that a porous layer and a glass-like layer are formed on the foil surface due to the laser ablation and the condensation afterwards and it is consistent with the laser ablated specimen’s metallographic analysis.