Physics of picosecond pulse laser ablation
| Autor: | Alexander M. Rubenchik, Nan Shen, Sonny Ly, Manyalibo J. Matthews, Jeff D. Bude, Raluca A. Negres, Rajesh N. Raman, Wesley J. Keller, James S. Stolken, Gabe Guss, Jae-Hyuck Yoo |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Physics Laser ablation business.industry medicine.medical_treatment General Physics and Astronomy 02 engineering and technology 021001 nanoscience & nanotechnology Ablation Laser 01 natural sciences Fluence law.invention Wavelength Full width at half maximum Optics law Cavitation 0103 physical sciences medicine 0210 nano-technology business Ejecta |
| Zdroj: | Journal of Applied Physics. 125:085103 |
| ISSN: | 1089-7550 0021-8979 |
| Popis: | This study investigates the physical processes involved in picosecond pulse (20-28 ps FWHM) laser ablation of Al 6061, 316L stainless steel, and undoped crystalline Si (〈100〉) over a range of laser wavelength (355 nm and 1064 nm) and fluence (0.1-40 J/cm2). Experimental measurements of material ablation rate show enhanced removal at the 355 nm wavelength, primarily due to laser-plasma interaction (LPI) within the ablative plume that approaches an order of magnitude increase over the measured removal at 1064 nm. A transition in the ablation rate at 355 nm is identified around ∼10 J/cm2 above which the removal efficiency increases by a factor of two to three. Multi-physics radiation hydrodynamic simulations, considering LPI effects and utilizing a novel mixed-phase equation of state model, show that the transition in ablation efficiency is due to the onset of melt ejection through cavitation, where laser-driven shock heating sets the depth of melt penetration and the ensuing release wave from the ablation surface drives cavitation through the imposition of tensile strain within the melt. High-speed pump-probe imaging of the ejecta and ejecta collection studies, as well as scanning electron microscopy of the ablation craters, support the proposed cavitation mechanism in the higher fluence range. The ablation process is critically influenced by LPI effects and the thermophysical properties of the material. |
| Databáze: | OpenAIRE |
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