Laser drilling is a conventional technology for drilling cooling holes into turbomachinery components such as turbine blades. The laser drilling process often causes microstructure changes and induces defects such as recast layers and cracks. These effects lead to a reduction of lifetime of the components. The defects are caused by the melt dominated drilling process by using pulse durations in the range of some 100 µm up to a few ms. A solution of this problem is the use of ultrashort pulsed laser radiation with pulse durations in the range of some 100 fs up to a few ps. Thus, thermal effects can be avoided. Unfortunately, this drilling process takes 2.5 min for one hole with a diameter of 500 µm and a length of 3 mm. Thus, the aim of this work is to combine the productive process by using ms pulsed fiber laser radiation with subsequent ablation of existing recast layers at the hole wall by using ultrashort pulsed laser radiation.

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Result report, Thermisch hochbelastete offenporige und gekühlte Mehrschichtsysteme für Kombi-Kraftwerke, SFB 561, RWTH Aachen University, Aachen, Germany
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Poprawe
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Springer
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Germany
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Friedrichs
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Verfahrenstechnische Grundlagen für das Bohren mit ultrakurzgepulster Laserstrahlung
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master seminar colloquium presentation
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31st March 2014
,
RWTH Aachen University
,
Aachen, Germany
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