脉冲激光烧蚀氩晶体颗粒的分子动力学模拟

采用分子动力学方法对氩晶体颗粒在皮秒脉冲激光照射下内部发生的传热过程以及相变现象进行模拟研究.通过记录氩原子速度和原子位置随时间的变化情况分析了颗粒内热量的传递过程,并计算了单位体积内氩原子数目的空间分布情况以及随时间的变化规律,从而分析了颗粒内部的相变过程.研究结果表明:当激光强度较低时,晶体内部仅仅发生传热过程而没有熔化发生,加入的激光能量随时间由外向内传递;当激光强度增加到足够晶体熔化的时候会发生相变,此时固液相态之间并没有明显的界面,而是存在一个纳米级别的过渡区域;当照射的激光强度增加时,过渡区域的移动速度和移动深度都将增加.

Molecular Dynamics Simulation of Argon Crystal Particle Irradiated by Pulsed Laser

The phenomena of heat transfer and phase change of solid argon crystal irradiated by pulsed laser was studied through the molecular dynamics simulation.In order to analyze the process of heat transfer inside the particle,the changes of velocities and locations of atoms were recorded at different time.Then the process of phases change was discussed through analyzing the variation of the number of argon molecules per unit volume.The calculation results show that when the laser intensity is low,no melting will happen.When the laser energy is increased enough,the phase change occurs and a transitional area of nanometer level instead of a clear interface is revealed between solid and liquid phase.The moving speed and moved depth of the transition zone increase with the increasing of laser intensity.