Experimental Study of Water-Assisted Nanosecond Laser Processing of Microvias in IN718 High-Temperature Alloy

In this paper, the optimal parameters of the laser concentric circle (from outside to inside) scanning processing method are investigated by infrared nanosecond laser perforation of nickel-based high-temperature alloy (IN718) in air. Based on the optimal parameters, the effects of the backwater assisted and different graded scanning optimization on the morphology of microvias are investigated, and the advantages of the optimized scanning method are summarized. The results show that the laser energy distribution on the material surface can be adjusted by scanning path graded optimization in air to eliminate the negative effect of excessive heat accumulation in the center of the scanning path to improve the taper of the microporous holes, and the combined effect of water-assisted water evaporation and boiling scouring, water buoyancy, and impact force generated by the collapse of bubbles can reduce the scope of the heat-affected zone and reduce the melt buildup and spraying of the microporous holes at the inlet and outlet of the microporous holes. The combined effect of water buoyancy and the impact force generated when the bubble collapses can reduce the scope of the heat-affected zone and minimize the accumulation of melt and spatter at the inlet and outlet of the microvia. It provides a reference for water-assisted infrared nanosecond laser processing and its optimization process.