Simulation study on the flow field characteristics of abrasive water jet polishing at different angles based on fused quartz laser element

Abstract

The main factor affecting the laser damage resistance of optical components is the damage precursor introduced in the manufacturing process. Some studies have shown that the ideal intrinsic matrix of fused quartz has a laser radiation damage threshold of up to 100J/cm2, but the manufactured optical components are far below this index. Therefore, effectively inhibiting or even eliminating the damage precursor is the key to improve the anti-laser damage performance of optical components. Abrasive Water Jet Polishing (AWJP) technology mainly removes materials through the collision and shear between abrasive particles and the workpiece surface, which has the characteristics of non-damage and non-contact processing. However, due to the small size of Tool Influence Function (TIF) and low efficiency, it is still challenging to achieve widespread application. In this paper, we analyzed the flow field characteristics near the workpiece surface when different nozzle tilt angles were used for processing under two different machining methods: maintaining the jet length unchanged and maintaining the standoff distance unchanged and corrected the pressure distribution. It was found that the changes in pressure distribution and shear stress distribution in the impact zone under different nozzle tilt angle conditions will result in a change in the width of the Gaussian-shaped TIF obtained after nozzle rotation machining. In addition, under the condition of the same nozzle tilt angle, the TIF of Gaussian shape with larger size can be obtained by using the processing method that keeps the standoff distance constant.