激光等离子体法清洗微纳颗粒的物态变化研究

为了探究激光等离子体冲击波清洗过程中微纳颗粒的物态变化特性，针对单晶硅表面Al微纳颗粒进行了清洗实验；结合等离子体传播规律与有限元法模拟了颗粒内部的应力和温度变化情况，得到了颗粒相变和演化的规律。结果表明，大颗粒与中颗粒数量明显减少，尺寸由原来的0.5μm~3μm变为0.1μm~1μm；颗粒的物态变化主要是冲击波瞬时高温高压作用所致，颗粒内最大应力达到1GPa，最大温度达到1100K；颗粒在冲击波作用下发生了破裂与相变，细小颗粒数量增多并粘附在样品表面，增大了清洗难度。此研究可为激光清洗颗粒的理论和应用提供参考。

Study on the state change characteristics of cleaning micro-nano particles by laser plasma method

In order to explore the characteristics of the state change of micro-nano particles during the laser plasma shock wave cleaning process, cleaning experiments were carried out for Al micro-nano particles on the surface of single crystal silicon; combined with the plasma propagation law and finite element method, the internal stress and temperature changes of the particles were simulated under the circumstances, and the law of phase transition and evolution of particles was obtained. The results show that the number of large and medium particles is significantly reduced, and the size is changed from 0.5μm~3μm to 0.1μm~1μm; the change in the state of the particles is mainly caused by the instantaneous high temperature and high pressure of the shock wave, and the maximum stress in the particles reaches 1GPa. The maximum temperature reaches 1100K; therefore, the particles break and phase change under the action of the shock wave, and the number of fine particles increases and adheres to the sample surface, which increases the difficulty of cleaning. This research can provide reference for the theory and application of laser cleaning particles.