High aspect ratio cutting of metals using water jet guided laser

We report on high aspect ratio cutting of aluminum, titanium, and steel using a water jet guided laser system equipped with a frequency doubled Nd:YAG laser. The influence of the laser power, pulse repetition rate, and number of passes on the cutting depth is investigated. High cutting depth can be achieved with high laser powers, low pulse repetition rates, and a high number of passes. The maximum cutting depth is determined to 8 mm in aluminum, 4.7 mm in titanium, and 1.5 mm in steel, respectively. The effective cutting velocity of 8 mm aluminum with 40 W laser power, in a multi pass process is determined to 0.1 mm/s. The kerf width is independent of both the chosen process parameters and the cutting depth, being in the range between 100 and 120 mu m. This results in high aspect ratios of up to 12.5 in steel, 39.2 in titanium, and 66.7 in aluminum.