Experimental investigation and optimization on trepanning drilling in K24 superalloy by femtosecond laser via orthogonal experiment

To optimize the hole-making process and minimize the cost of time and other expenses, this paper explores femtosecond laser trepanning drilling of K24 alloy, focus on the control of the laser process parameter groups on the diameter, circularity, taper and material removal rate (MRR) for the micro-hole formation. The laser power, repetition rate, focal position, and cutting speed are selected as independent design factor for Taguchi orthogonal array with four levels employed to design and conduct the experiments. The effect of laser parameters on processing performance is evaluated in terms of both mean response and signal-to-noise (S/N) ratio, which are used to investigate the effect of the levels of the four process variables on the results in order to optimize and control the output. The experimental results reveal that the exit circularity, taper and MRR are affected mainly by the laser power. In addition, the entrance diameter increases with the laser power, and the exit diameter is decreased with the cutting speed increasing. However, the repetition rate has no significant effect on the above processing performance within the range of values investigated. Finally, the experimental results verified that the optimized laser hole–making parameters can improve the shape and dimensional accuracies of the obtained micro-holes. This optimized combination of laser processing parameters provides an effective method to improve the hole-making quality and efficiency.