Material removal rates in ultra-high-speed micro machining using a picosecond laser

Abstract

Ultrashort pulse lasers combined with megahertz level repetition rates allow use of higher production speeds. In this paper in presented experiments made with pulse laser to stainless steel and brass samples with high-speed machining up to about 30 m/s. Samples were attached to a high-speed rotating spindle, which can be rotated up to 80000 rpm with a small load. High machining speed is used to lower pulse overlap. With high pulse overlap, part of the beam power is reflected, scattered and absorbed into vaporizing metal ablated by the previous pulse. Additionally, heat conducted to the material decreases due shorter interaction to the material. The process efficiency was analyzed from the laser machined grooves. In addition, laser’s material removal rate was observed. Grooves were analyzed with a profilometer and an optical microscope, and material removal rates in the grooves were calculated.Ultrashort pulse lasers combined with megahertz level repetition rates allow use of higher production speeds. In this paper in presented experiments made with pulse laser to stainless steel and brass samples with high-speed machining up to about 30 m/s. Samples were attached to a high-speed rotating spindle, which can be rotated up to 80000 rpm with a small load. High machining speed is used to lower pulse overlap. With high pulse overlap, part of the beam power is reflected, scattered and absorbed into vaporizing metal ablated by the previous pulse. Additionally, heat conducted to the material decreases due shorter interaction to the material. The process efficiency was analyzed from the laser machined grooves. In addition, laser’s material removal rate was observed. Grooves were analyzed with a profilometer and an optical microscope, and material removal rates in the grooves were calculated.