Investigation of the process parameter effects on the hole geometry characteristics in laser drilling of Hastelloy X superalloy

In recent years, laser drilling is used as a new process for micro drilling with high precision, less time and high aspect ratio in various industries, particularly in the aerospace industry. To improve the quality of drilling process, identification of the process parameters and investigation of their influence on the output characteristics are necessary. In present study, laser percussion drilling process was performed on Hastelloy X nickel-based superalloy and the effect of process parameters including laser frequency, pulse width and laser beam keeping time was investigated on the hole geometry characteristics (hole entrance and exit diameter, hole entrance and exit circularity and hole taper). The results indicate that by increasing the laser frequency, hole entrance and exit diameter increases but hole entrance and exit circularity and hole taper decrease. By increasing the pulse width, hole entrance and exit diameter increases but hole entrance and exit circularity decreases. Also, with increasing the pulse width, hole taper decreases. When the laser beam keeping time increases, hole entrance and exit diameter increases but hole entrance and exit circularity and hole taper decrease.