| Autor: |
Menold, T., Ametowobla, M., Köhler, J. R., Werner, J. H. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 2018, Vol. 124 Issue 16, pN.PAG-N.PAG, 11p, 1 Black and White Photograph, 3 Diagrams, 3 Charts, 8 Graphs |
| Abstrakt: |
Spot laser melting of monocrystalline silicon leads to characteristic surface structures that are defined by a peak and a quasi-periodic ripple structure. The structures are created by a 50–100 μ s pulsed infrared fiber laser and are approximately 30–100 μ m in size. We present an analytical model explaining the creation of the peak by the density anomaly of silicon. Additionally, we show that the quasi-periodic ripple structure stems from a frozen capillary wave, which allows us to determine the resolidification velocity from the ripple radii. For a structure of molten radius R m e l t = 41.5 μ m , we determine a resolidification velocity v r e = 56.6 ± 9.2 cm / s. A numerical model for the same structure yields v r e = 49.2 cm / s , which agrees with the value determined from the ripple pattern. The capillary wave is excited in the melt pool due to thermocapillary convection. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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