Measurement of laser absorptivity for operating parameters characteristic of laser drilling regime
| Autor: | Matthieu Schneider, Rémy Fabbro, Laurent Berthe, Maryse Muller |
|---|---|
| Přispěvatelé: | Laboratoire Procédés et Ingénierie en Mécanique et Matériaux (PIMM), Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM) |
| Rok vydání: | 2008 |
| Předmět: |
Matériaux [Sciences de l'ingénieur]
Acoustics and Ultrasonics laser drilling 02 engineering and technology 01 natural sciences [SPI.MAT]Engineering Sciences [physics]/Materials law.invention Optics law reflectivity 0103 physical sciences Vaporization [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering Rayleigh–Taylor instability Absorption (electromagnetic radiation) Optique / photonique [Sciences de l'ingénieur] 010302 applied physics Chemistry business.industry Génie des procédés [Sciences de l'ingénieur] Molar absorptivity 021001 nanoscience & nanotechnology Condensed Matter Physics Laser Surfaces Coatings and Films Electronic Optical and Magnetic Materials Attenuation coefficient [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic absorptivity 0210 nano-technology business Intensity (heat transfer) Laser drilling |
| Zdroj: | Journal of Physics D: Applied Physics Journal of Physics D: Applied Physics, IOP Publishing, 2008, 41 (15), pp.6. ⟨10.1088/0022-3727/41/15/155502⟩ |
| ISSN: | 1361-6463 0022-3727 |
| Popis: | Publisher version : http://iopscience.iop.org/0022-3727/41/15/155502/ Laser drilling in the percussion regime is commonly used in the aircraft industry to drill sub-millimetre holes in metallic targets. Characteristic laser intensities in the range of 10 MW cm−2 are typically employed for drilling metallic targets. With these intensities the temperature of the irradiated matter is above the vaporization temperature and the drilling process is led by hydrodynamic effects. Although the main physical processes involved are identified, this process is not correctly understood or completely controlled. A major characteristic coefficient of laser–matter interaction for this regime, which is the absorptivity of the laser on the irradiated surface, is still unknown, because of the perturbing effects due to laser beam geometrical trapping inside the drilled hole. So, by using time resolved experiments, this study deals with the direct measurement of the variation of the intrinsic absorption of aluminium, nickel and steel materials, as a function of the incident laser intensity up to 20 MW cm−2. We observe that for this incident intensity, the absorptivity can reach up to 80%. This very high and unexpected value is discussed by considering the microscopic behaviour of the heated matter near the vapour–liquid interface that undergoes possible Rayleigh–Taylor instability or volume absorption |
| Databáze: | OpenAIRE |
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