Forscherverbund: Grundlagen der präzisen, optischen Behandlung von Festkörpern (PROBE). Teilvorhaben

: Franz, U.; Luft, A.; Kaspar, J.; Emsermann, A.

Abstract
The report given focuses on a comparative study of laser-drilled micro holes which were produced in metals, silicon and fused silica using different short-pulse lasers (copper vapour laser, Nd:YAG laser, Nd:YLF-laser, Ti:sapphire laser) under a wide range of processing parameters (pulse widths: 50 ns to 100 fs, fluencies 10 J/cm2 to 1000 J/cm2, peak power densities 108 W/cm2 to 1015 W/cm2, pulse repetition rates 10 Hz to 7 kHz). Typically, the laser-drilled holes were 0,1 mm to 1 mm deep with entrance d e production of percussion-drilled holes with a high rate of material ablation (about 1 5m per pulse) does not lead to any appreciable reduction in the melt component, material re-deposition or thermal load on the wall of the hole. Using small pulse energies it is possible to reduce the mechanical loads on the material due to the laser-induced pressure in the drill channel whereas the formation of heat affected zones and of thermal stresses due to cooling down of heat affectedzones can be reduced.

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