Water Flow Characteristics for Water-Assisted Laser Processing
X-L. Zhao, J. Zhou, Z-X. Zhong, Y-H. Long, Y-X. Huang and J-D Mao
In the solution-assisted laser processing technology, the motion characteristics on the target surface layer have a significant effect on the machining effect. Based on the hydrodynamics, to water-assisted devices in the water-assisted laser processing, the flow field characteristics of the fluid above the target are simulated by Fluent software. The influence of the water layer thickness on the water-assisted laser processing was analysed from the view of the water layer characteristics and the water-assisted laser processing technology was used to optimize by the liquid layer parameters. Simultaneously, the experiment of water-assisted laser processing was carried out, the etching depth, etching width and heat affected zone (HAZ) parameters were tested in the process with different liquid layer thickness, and the reason of the water flow characteristics influence on machining effect was analysed. Water layer flow analysis and experimental studies have shown, the water layer is laminar flow in the water layer thickness of 1 mm, the water layer is the most stable, and it is the most suitable for closed underwater laser processing. At the same time, the experimental results also verify the simulation results of flow field characteristics. This study provides a new idea for selecting the thickness of liquid layer, the location of the workpiece and selecting the inlet speed of fluid in the water-assisted laser processing.
Keywords: Fibre laser, water-assisted laser processing, Fluent, heat affected zone (HAZ), flow field characteristics, velocity field, simulation