"Quartz (Dielectric) and Galvanized Iron (Metal) were tested with respect to their response when irradiated with 120 fs laser pulses at various pulse energies and pulse numbers. Theoretical models governing their ablation mechanisms were reported and comparative results on the investigations were analyzed. The experiments were carried out in air within fluence ranges between 0.7 J/mm2 to 700 J/mm2. A combination of energy per pulse between 0 .0lxl0-3 W to 0 .2 x10-3 W and number of pulses between 1 and 50 were used. The changes induced in the surface morphologies were analyzed with Optical Microscope, SEM and FESEM. From the experimental data and calculated incident energy density, damage threshold diameters and ablation depth were calculated to explain lateral & vertical precision and published modeling results were verified. After the observations, it was concluded that low fluence regime below 70 J/mm2 with a combination of low energy per pulse (< 0.1 x 10-3 W) and moderate number of pulses (between 10 & 25) is a better way to machine the target materials using the Femtosecond laser machining system addressed in this work. Finally, considering the fact that laser ablated areas undergo severe thermal and mechanical stresses which results in increased hardness & elasticity, a method to preferentially fabricate materials with desired hardness on surfaces is proposed"--Abstract, p. iii
Miller, F. Scott, 1956-
Mechanical and Aerospace Engineering
M.S. in Mechanical Engineering
University of Missouri--Rolla
xi, 58 pages
© 2007 Naveen Kumar Kondameedi, All rights reserved.
Thesis - Restricted Access
Laser pulses, Ultrashort
Print OCLC #
Kondameedi, Naveen Kumar, "A comparative study on surface modifications induced in a dielectric material and a metal using femtosecond laser" (2007). Masters Theses. 5974.
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