Multi-energy field simulation and experimental research on backside water assisted laser processing for thin-walled irregular metal micro-holes

The cooling holes of the blade of aircraft engines play an important role in improving their performance. In this paper, a water-assisted laser machining method is proposed as a means of achieving high-quality manufacturing of the cooling holes. Multi-energy field simulations and extensive experiments were carried out to explore the processing effects of this new composite manufacturing technology. The mechanism of the backside water-assisted laser machining process was analyzed using finite element multi-energy field simulation. It was demonstrated that the cooling effect of the backside water flow became increasingly significant as the number of laser pulses increased. The experimental results of the backside water-assisted laser drilling for the straight and inclined circular, square and trapezoidal holes exhibited superior performance. It was demonstrated that the entrances and exits of the micro-holes prepared by the water-assisted laser drilling process exhibited increased dimensions, enhanced entrance morphology, superior quality of the hole wall, and a notable reduction in thermal defects. The interaction between the liquid and the laser enabled the secondary removal of the hole wall material, which in turn improved the quality of micro-hole.