Highspeed Laser Micro Processing using Ultrashort Laser Pulses

摘要

This paper discusses results obtained in highspeed laser micro processing of zirconium oxide ce-ramic and stainless steel. High-PRF (pulse repetition frequency) femtosecond laser systems were joined together with fast galvanometer scanner systems. A high average laser power (31.7 W) and fast scan speeds (17.1 m/s) were applied in order to increase material removal. The influence of av-erage laser power, laser energy and repetition rate on both the volume ablation rate and the machin-ing quality was studied. The maximum volume ablation rate for zirconium oxide was 70.3 μm3 per pulse, obtained with pulses of 5.9 μJ energy and 1.02 MHz. It is demonstrated that material removal on zirconium oxide will be strongly affected by heat. Stainless steel was irradiated with a maximum laser power of 31.7 W and various repetition rates. The maximum material removal rate was found to be 6.8 mm3 / min, achieved with laser pulses of 0.85 J/cm2 fluence. The feasibility of the high-speed laser technology in micro processing is verified by machining examples. In addition, a de-monstrator of 80 x 80 mm2 was machined with a processing rate as high as 25 cm2 / min.