Femtosecond laser drilling in nickel-based alloy assisted by ultrasonic vibration

High-temperature nickel-based alloys have excellent high-temperature strength, good oxidation and thermal corrosion resistance, good fatigue properties, fracture toughness and other comprehensive properties. In order to realize the processing of high-quality micro-holes in nickel-based high-temperature alloy (GH3536), this paper focuses on ultrasonic vibration-assisted femtosecond laser technology, and adopts the method of controlling variables to study the influence of different parameters on processing quality with/without ultrasonic, and draws out the influence law of different parameters on the processing quality of micro-holes by comparing the micro-hole inlet width, ablation depth, and degree of round deviation with other parameters including the number of laser single-layer scanning, laser single-layer scanning frequency, ultrasonic frequency, and ultrasonic power. The results indicate that as the number of scans increase, so do the ablation area of holes and rate of material removal; conversely, as single-layer scanning times increase, processing speeds drop, processed material removal rates rise, and the radius of material entry into the hole increases as well. With more consistent ablation of micropores, smoother inner wall edges, and less circular deviation than in absence of ultrasound, ultrasonic vibration contributes to better processing quality. During the processing process, using an ultrasonic power of 7.5W-11.25W and an ultrasonic frequency of 20kHz-50kHz may improve processing quality and satisfy the high temperature nickel base alloy processing requirements.