Author:
Stafe Mihai,Vladoiu Ionut,Popescu Ion
Abstract
AbstractThe dependence of the ablation rate of aluminium on the fluence of nanosecond laser pulses with wavelengths of 532 nm and respectively 1064 nm is investigated in atmospheric air. The fluence of the pulses is varied by changing the diameter of the irradiated area at the target surface, and the wavelength is varied by using the fundamental and the second harmonic of a Q-switched Nd-YAG laser system. The results indicate an approximately logarithmic increase of the ablation rate with the fluence for ablation rates smaller than ∼6 μm/pulse at 532 nm, and 0.3 μm/pulse at 1064 nm wavelength. The significantly smaller ablation rate at 1064 nm is due to the small optical absorptivity, the strong oxidation of the aluminium target, and to the strong attenuation of the pulses into the plasma plume at this wavelength. A jump of the ablation rate is observed at the fluence threshold value, which is ∼50 J/cm2 for the second harmonic, and ∼15 J/cm2 for the fundamental pulses. Further increasing the fluence leads to a steep increase of the ablation rate at both wavelengths, the increase of the ablation rate being approximately exponential in the case of visible pulses. The jump of the ablation rate at the threshold fluence value is due to the transition from a normal vaporization regime to a phase explosion regime, and to the change of the dimensionality of the hydrodynamics of the plasma-plume.
Subject
General Physics and Astronomy
Reference24 articles.
1. J.F. Ready, Effects of high-power laser radiation (Academic Press, New York-London, 1971)
2. D. Bauerle, Laser processing and chemistry (Springer-Verlag, Berlin-Heidelberg-New York, 2000)
3. I.M. Popescu et al., Aplicatii ale laserilor, (Ed. Tehnica, Bucuresti, 1979, in Romanian)
4. D. Bauerle, Proceedings of an International Conference Laser Processing and Diagnostics, University of Linz (Springer-Verlag, Berlin Heidelberg, 1984)
5. M. von Allmen, A. Blatter, Laser-Beam Interactions with Materials (Springer-Verlag, Berlin, 1995)
Cited by
24 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献