水下激光加工的爆发沸腾实验研究

The Explosive Boiling Experiment Study on Underwater Laser Processing

为了探寻水下脉冲激光加工的合适焦点位置,并与空气中的加工效果进行对比,采用改变激光焦点位置轰击导热硅胶片的方法进行实验。用激光扫描共聚焦显微镜测量凹坑尺寸,并绘制了凹坑深度、宽度与焦点位置趋势图。用高速摄影仪拍摄水下激光加工现象,得到了等离子体闪光及其诱导产生的空化泡现象,并进行了理论分析和实验验证。结果表明:当焦点位置在材料表面以下时,水下激光加工是热传导、等离子体冲击波及空化泡冲击波共同作用的结果,激光加工效率与激光焦点位置密切相关。

In order to find an appropriate focus position of underwater pulse laser processing,and then compared with the processing effect in the air,the experiment by changed the laser focal distance to bombardment thermal conductive silicone piece was carried out. Used a laser scanning confocal microscope to measure the pit size,and draw the pit depth/width-focus distance trend chart. Used a high-speed photography to shoot underwater laser processing phenomenon,got the phenomenon of plasma flash and cavitation bubbles,this phenomenon had been theoretical analysis and experimental verification. The results show that when the focus position is below the surface of the material,mechanism of underwater laser processing is heat transfer,the plasma shock wave and cavitation bubble burst combination result. Laser machining efficiency is closely related with the laser focal position.